MODELS VSP6020, VSP2050, VSP4030 & VSP12010 High Power Switching DC Power Supplies Instruction Manual TABLE OF CONTENTS SECTION DESCRIPTION PAGE NO. 1 TEST INSTRUMENT SAFETY 1 2 GENERAL INFORMATION 2 3 INSTALLATION 6 4 OPERATING INSTRUCTION 10 5 MAINTENANCE 19 6 REMOTE INTERFACE 21 7 CUSTOMER SUPPORT 63 8 WARRANTY INFORMATION 64 9 SERVICE INFORMATION 65 Section 1 Test Instrument Safety WARNING Normal use of test equipment exposes you to a certain amount of danger from electrical shock because testing must sometimes be performed where exposed voltage is present. An electrical shock causing 10milliamps of current to pass through the heart will stop most human heartbeats. A Voltage as low as 35 volts dc or ac (rms.) should be considered dangerous and hazardous since it can produce a lethal current under certain conditions. Higher voltages pose an even greater threat because such voltage can more easily produce a lethal current. Your normal work habits should include all accepted practices to prevent contact with exposed high voltage and to steer current away from your heart in case of accidental contact with high voltage. You will significantly reduce the risk factor if you know and observe the following safety precaution. 1. Don't expose high voltage needlessly. Remove housings and covers only when necessary. Turn off equipment while making test connections in high voltage circuits. Discharge high voltage capacitors after removing power. 2. If possible, familiarize yourself with the equipment being tested and the location of its high voltage points. However, remember that high voltage may appear at unexpected points in defective equipment. 3. Use an insulated floor material or a large, insulated floor to stand on and an insulated work surface on which to place equipment and make certain such surfaces are not damp or wet. 4. Use the time proven "one hand in the pocket" technique while handling an instrument probe. Be particularly careful to avoid contacting a nearby metal object that could provide a good ground return path. 5. When testing ac powered equipment, remember that ac line voltage is usually present on some power input circuits such as the on-off switch, fuses, power transformer etc. any time the equipment is connected to an ac outlet, even if the equipment is turned off. 6. Some equipment with a two-wire ac power cord, including some with polarized power plugs, is the "hot chassis" type. This includes most recent television receivers and audio equipment. A plastic wooden cabinet insulates the chassis to protect the customer. When the cabinet is removed for servicing, a serious shock hazard exists if the chassis is touched. Not only does this present a dangerous shock hazard, but damage to test equipment. Always connect an isolation transformer between the ac outlet and the equipment under test. The B&K Precision Model TR-110 or 1604A Isolation Transformer or Model 1653A or 1655A AC Power Supply is suitable for most applications. To be on the safe side, treat all two-wire ac equipment as "hot chassis" unless you are sure it is isolated chassis or an earth ground chassis. 7. On test instruments or any equipment with a 3-wire ac power plug, use only a 3-wire outlet. This is a safety feature to keep the housing or other exposed elements at earth ground. 8. B&K Precision products are not authorized for use in any application involving direct contact between our product and the human body or for use as a critical component in a life support device or system. Here "direct contact" refers to any connection from or to our equipment via any cabling or switching means. A "critical component" is any component of a life support device or system whose failure to perform can be reasonably expected to cause failure of that device or system or to affect its safety or effectiveness. Never work all alone. Someone should be nearby to render aid if necessary. Training in CPR (cardiopulmonary resuscitation) first aid is highly recommended. 1 Section 2 General information 2.1 INTRODUCTION 2.2 FEATURE 2.3 MARKINGS 2.4 INTERFACE 2.5 SPECIFICATION 2.6 ORDERING INFORMATION 2.1 INTRODUCTION The VSP SERIES power supplies are designed to deliver power in constant voltage and constant current mode by switch mode conversion in sleek 1U high cabinet and in a 19'' rack construction. This series comprises the two device soft switching technology that yields very high efficiency of conversion for dc-to-dc converter part. Also it comprises power factor correction circuity, which shapes the input current to follow the voltage to maintain almost unity power factor at full load, and limits the current harmonics in the input line. It provides the user the option of isolated analog voltage, current and resistance programming with built-in isolation amplifiers. It gives the option to monitor the isolated signals with the option to change either from 0 to 5 Volts or from 0 to 10 Volts, for output voltage and current from 0 to full-scale level. It provides the display of the output voltage, over voltage set level and current with 3-digit LED displays. Piggyback series pass device ensures the ripple and noise levels to very low values. Current sharing facility in the module gives the advantage to increase the power with ease and the vents in the front and the rear enables it with absolutely zero stacking. The module can be switched on/off through the front panel ON/OFF switch or remote switch on rear panel. VSP series provides digital interface options for remote programming from PC. The digital interface provides 12-bit resolution for control as well as monitoring the output. 2 Some of the features of the power supply are listed below: 2.2 FEATURES MAINS OPERATED, WITH WIDE INPUT RANGE. POWER FACTOR CORRECTED INPUT. ISOLATED D.C. OUTPUT. 1200-WATT OUTPUT POWER CONSTANT VOLTAGE OPERATION FROM 0 TO FULL-SCALE LEVEL. CONSTANT CURRENT OPERATION FROM 0 TO FULL-SCALE LEVEL. OVER VOLTAGE CONTROL FACILITY. REMOTE SENSING FACILITY. PARALLELABLE CURRENT SHARING OUTPUT. HIGH OVERALL EFFICIENCY - 80% TYPICAL. VERY LOW OUTPUT RIPPLE AND NOISE. INPUT EMI FILTERING TO MEET EN55022 CLASS A. 20 MILLISECOND HOLD-UP TIME. TWO FRONT PANEL DPMS. FOR V / O.V AND I. MULTI TURN POTENTIOMETERS FOR V, O.V AND I SET. FRONT PANEL OUTPUT TERMINALS FOR MONITORING. SLEEK, 1U HIGH, 19 INCH RACK CONSTRUCTION. INTERNAL FORCED AIR COOLING WITH ZERO STACKING. ISOLATED ANALOG VOLTAGE, CURRENT AND RESISTANCE PROGRAMMING AND MONITORING. REMOTE ON/OFF FACILITY. RS232/ GPIB/ INTERFACE. 2.3 MARKINGS The unit has the name PROGRAMMABLE PFC DC SUPPLY written clearly on the top of the front panel. The Model Number and ratings are also clearly written on the front panel. The ratings are clearly written on the rear panel, just near the output terminals. 2.4 INTERFACE The unit has both local as well as remote controls. For Remote operation, the series offers analog as well as digital interface or both. Both RS 232 or GPIB digital interfaces can be provided. 3 2.5 SPECIFICATIONS Output Specification Model Power Output Voltage Output Current Ripple rms. (10Hz to 1MHz) Noise (10Hz to 20MHz) Programming Resolution Voltage Current VSP6020* 1.2KW 0-60V 0-20A <10mV <45mVpp VSP2050* 1.2KW 0-20V 0-50A <15mV <45mVpp VSP4030* 1.2KW 0-40V 0-30A <10mV <45mVpp VSP12010* 1.2KW 0-120V 0-10A <20mV <45mVpp (Digital Interface), LSB (not LED displays) 20 mV 10 mV 10 mV 100 mV 10 mA 20 mA 10 mA 10 mA Output Programming Accuracy Voltage Current (Analog Programming 0 To 5V & 0 To 10V) 0.5 % of F. S. 1 Digit (spec. for all VSP models) 0.5 % of F. S. 1 Digit (spec. for all VSP models) Meter Accuracy Voltage Current +/- 0.2% of F.S. +/- 3 Digit. (spec. for all VSP models) +/- 0.2% of F.S. +/- 3 Digit. (spec. for all VSP models) Regulation CV Line Regulation (mV) CC Line Regulation (mV) CV Load Regulation (mA) CC Load Regulation (mA) 0.1 % of F.S (spec. for all VSP models) 0.1 % of F.S (spec. for all VSP models) 0.1 % of F.S (spec. for all VSP models) 0.1 % of F.S (spec. for all VSP models) Output Specification Stability Efficiency< Transient Response 0.05% 80% Minimum 250 microseconds for load change from 40% to 90% Mode Of Operation Local Mode Digital Interface Through front panel potentiometer for voltage, current and over voltage and Push switch for Output ON/ OFF control. Remote Mode Interface Analog programming of voltage and current.Voltage: 0 - 5 volts or 0 - 10 volts for output voltage and current, selection through DIP-switch. Resistance: 0 - 4.85k ohms from 0 to full-scale level. RS-232 / GPIB * = Specification also apply to corresponding GPIB model F.S = Full Scale. Full scale will be different for each model. Example: If you have a VSP2050 and you are measuring the voltage meter accuracy, the meter can not off more than 0.3V (20V + 0.2% +3 digit). Note: 3 digits refferes to the power supply displays least significant digit. 4 Protections Over voltage protection Over temperature protection Programmable through POT in local mode and through digital interface in remote mode. Through 90 C. thermal switch on heat sink. Input specifications Mains Input Range Input Frequency Input Power Factor Inrush Current 95Vac to 264Vac. 47 To 63 Hz 0.99 On Full Load At Nominal Input. Limited By NTC Operating Environment Temperature Relative Humidity Storage Temperature Warm-up Time 0 - 50C < 80% rh - non condensing - 20C. to + 70C. 15 minutes. Safety Standards EMI Filtering Safety Class EN55022 Class-A EN60950 Mechanical Specifications Weight (approx.) Dimensions (WxHxD) Dimensions with rubber feet 13.7lbs. (6.2 KG.) 19 x 1.75 x 18" (483 x 44.5 x 457mm) 19 x 2.13 x 20" (483 x 54 x 457mm) 2.6 ORDERING INFORMATION: MODEL NO DESCRIPTION VSP6020 60V, 20A power supply with opto-isolated analog interface and RS-232 VSP6020GPIB 60V, 20A power supply with opto-isolated analog interface and GPIB VSP4030 40V, 30A power supply with opto-isolated analog interfaceandRS-232 VSP4030GPIB 40V, 30A power supply with opto-isolated analog interface and GPIB VSP2050 20V, 50A power supply with opto-isolated analog interface and RS-232 VSP2050GPIB 20V, 50A power supply with opto-isolated analog interface and GPIB VSP12010 120V, 10A power supply with opto-isolated analog interface and RS232 VSP12010GPIB120V, 10A power supply with opto-isolated analog interface and GPIB 5 Section 3 Installation 3.1 INTRODUCTION 3.2 UNPACKING 3.3 INPUT POWER REQUIREMENTS 3.4 SYSTEM CONFIGURATION 3.5 INSTALLATION 3.6 TEST EQUIPMENT REQUIREMENTS 3.1 Introduction VSP series power supply is configured, calibrated and tested prior to shipment. This unit is therefore ready for immediate use upon receipt. The initial physical inspections should be made to ensure that no damage has been sustained during shipment. 3.2 Unpacking Inspect the shipping container before accepting it from the carrier. If damage to the container is evident, remove the instrument from the container and visually inspect it for damage to the instrument case and parts. If damage to the instrument is evident, a description of the damage should be noted on the carrier's receipt and signed by the driver or carrier agent. Save all shipping containers and material for inspection. Forward a report of any damage to the factory or the agent through which the unit is procured. Retain the original packing container if subsequent repackaging for return to the factory were required. Repackaging is straightforward and is essentially the reverse of the unpacking. Only subassemblies need to be repackaged for reshipment, use the original containers. Remove the Source module from its shipping container and inspect for any damage to the front panel and display module. Also check for any optional parts which may have been ordered by you. If the switch or display is heavily damaged or is broken then DO NOT switch-ON the instrument. Check the rear of the instrument for damage to Sockets or Fuse Holders. Inspect also the POWER-ON switch on the front panel. 6 3.3 Input Power Requirements The Model VSP power supply is configured at the factory to operate from 95-264 VAC at 47-63 Hz power line. 3.4 System Configuration The Model VSP series power supply comes in ready to use fashion and does not require any configuration in the field for operation in the local mode. For analog interface refer to the connector details for the connections. 3.5 Installation 1. AC Input Power Connection Connect a 3-pin power mains cord to the available line supply. Before connecting line ensure the following: a) The available line supply is compatible to your unit. b) The available line supply point is capable of supplying the maximum peak current and power. 2. Load Connections Refer fig.3.1A for load connection in local and remote sensing mode, the unit has 5mm brass studs on the rear panel for load connections for model up to 30A. The bus bar is provided from 30A onwards. For remote sensing and the current sharing option it is provided with separate 6 way terminal block. This is required if your load is far away & regulation needs to be maintained at load terminals. An output cable should be able to handle the full load current and maximum voltage and power under worst case conditions of temperature, humidity, mechanical abuse, and effects of long term aging. 3. Analog Interface Connections A 25 pin D type connector & DIP switch is provided for remote analog interface to the unit. There is 8 pin DIP switch associated with the function of analog interface. Refer to section 4.3.5 of chapter 4 for switch settings. 4. Turn-On Switch the POWER ON switch to the ON position. Soon the DPM will be turned on & the output voltage & current are displayed, if output on-off switch is in ON position. Voltmeter should display the voltage set by voltage control. Check the current meter. It must show zero (very low) current under no load. If not then please switch off the unit and call the service personnel. For details of TURN ON CHECK refer section 4.5 of CHAPTER 4. 7 3.6 Test Equipment Requirements The following instruments will be required to test the complete installation of the unit. 1). A four and half digit or better digital multimeter for verifying the voltage and current output of the unit. 2). A 20 MHz dual channel oscilloscope for verifying the Ripple in Output of the Source. 3). A Resistive load or an Electronic Load to take an input to suit the maximum output from the unit depending on the model and capacity of the channel of the Source. 8 Fig 3.1a : CONNECTION DETAILS IN LOCAL & REMOTE INTERFACE LOCAL MODE 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 REMOTE ON/OFF 17 AMX 18 VMX 19 AGND3 20 NC 21 VPSET 22 VMSET 23 IPSET 24 IMSET 25 NC NC VPROGI VPIN VPROGR AGND3 NC NC IPIN IPROGI IPROGR NC NC NC +12V AGND3 +S + -S NC CS BUS SWITCH CONFIGURATION (ON REAR PANEL) 12345678 O N 1 2 3 4 5 6 +S + -S NC CS BUS Output +VE 1 2 3 4 5 6 Output +VE Output -VE Output -VE LOAD LOCAL SENSING LOAD REMOTE SENSING 9 Section 4 Operating instruction 4.1 INTRODUCTION 4.2 FRONT PANEL DESCRIPTION 4.3 REAR PANEL DESCRIPTION 4.4 POWER ON CHECK 4.5 OPERATING INSTRUCTIONS IN LOCAL MODE 4.6 OPERATING INSTRUCTIONS IN ANALOG REMOTE INTERFACE 4.7 OPERATING INSTRUCTIONS IN DIGITAL INTERFACE 4.8 TRIP INDICATIONS 4.1 INTRODUCTION The VSP series Model is a variable switch mode power supply to provide wide range of DC supply from 0 to full-scale specified voltage. This chapter explains the operating procedure of the unit. The operation is very simple by providing POT control for voltage, current limit and over voltage protection limit and 8 way DIP switch along with 25 Pin D type connector for the remote programming interface. Optional RS232 interface or GPIB interface can be provided as per the order placed. In case of RS232 interface, a slide switch no. 7 on 8 pin DIP switch array on the rear panel facilitates either LOCAL/ RS232 communication interface or Analog programming. The unit is internally fan cooled. The air inlet vents are provided on the front panel. The air outlet is a rectangular slotted area on the 1U high rear panel, and is located between the A.C. input and D.C.output connectors. The instrument front panel and rear panel are described first in detail, explaining the layout, identification, function and usage of each item on the panel. The Turnon sequence and the procedure to use the major functions and operation of unit in digital interface are also explained. At the end all the ALARM indications, errors and warning signals are explained. In the same section procedures to clear the TRIP and ALARM conditions are discussed. 10 4.2 FRONT PANEL DESCRIPTION Figure 4.1 shows layout of front panel. On the front panel following controls and indicators are provided. 1. 2. 3. 4. 5. 6. 7. 8. 9. Main ON/OFF switch with neon indication. 3 digit display for Voltage/ Set Voltage/ Set Over Voltage indication 3 digit display for Current/ Set Current indication. 10 turn POT for voltage control. 10 turn POT for current control. 10 turn POT for over voltage protection control. Push switch to view set parameters in SET mode. Latch type Push switch for Output ON/OFF control. LED indications for CV, CC, Output ON, Trip, Remote, V set, I set, O/V set and Set mode. - The display shows 3 digit value for voltage and current parameters. The resolution of indication is 0.1 volt and 0.1 amp for voltage and current parameters. The display is used to show actual output voltage and current or to show set values of voltage, over voltage and set current limit in the set mode. The set mode is activated using Set key during output OFF condition. - CV LED indicates the constant voltage operation of power supply. - CC LED indicates constant current operation of power supply. - TRIP LED becomes ON either for over voltage trip condition or for over temperature trip condition. - Output ON/OFF can be controlled by push button switch (latch type) and LED turns ON if output is available. - Remote LED is provided for the digital interface option. It lights up when the power supply is controlled by external digital interface. - To view the set values of POT on the display press the SET key. Also LED's for each POT and common SET MODE Led is provided. - Also monitoring terminals of output are provided on front panel so that user can verify the output with calibrated meter. Additional earth terminal is also provided on front panel. 4.3 REAR PANEL DESCRIPTION The rear panel of the unit is shown in fig 4.2. The mains input connection is made through a mains cord and is located on the right side of the unit at the rear. A 20A fuse of type 'F' is used for line input range 95Vac to 264Vac,) provided at input. At the center are the oval shaped ventilation slots for air exhaust, for D.C. output 5mm brass studs or bus bars (as per the current specifications) are provided, next to it is 6 way terminal block for remote sensing and current share bus. Further is the 25 pin D-type connector for analog interfacing & the associated 8 pin DIP switch for selection of analog mode operation and it's associated modes of operation. Above the 25 pin D-type connector the provision is made for digital interface connection, which can be either GPIB or RS232. 11 12 13 1 14 15 6 2 16 12 7 3 11 4 8 17 10 17 19 20 9 17 18 5 21 22 24 26 23 Sr. No. 1 2 3 Description Input Line Cable Input Fuse Input R. F. Filter 4 5 6 7 8 9 10 11 12 13 VSP-PFC-1.2KW-1103D, PCB Input ON/OFF Switch Heat Sinks PFC Choke DC DC Converter Transformer VSP-DPM-CONT-1204D, PCB VSP-FAN-CNT-1103C, PCB VSPDDC-1.2KW-0704E, PCB Digital Interface PCB Output Power Terminals Sr. No. 14 15 16 17 18 19 20 21 22 23 24 25 26 25 26 Description Output Sense Terminals Analog Interface Connector DIP switches for Analog Interface selection Cooling Fans SBC-IEB-0504A, PCB (For GPIB) VSP-POT-IMON-0604A, PCB VSP-FPDAC CONV-0604A, PCB Voltage Monitoring Terminals VSP-DPM-1UFP-0604D, PCB Potentiometers for control SET, ON/OFF switch Assembly Earth Terminal Handles GENERAL ASSEMBLY DRAWING OF VSP SERIES POWER SUPPLY 13 4.3.1 LINE INPUT The mains input range is clearly indicated on rear panel. The unit comes standard with a U.S. standard plug and a mains input rating of 95VAC to 265VAC, 50/60Hz. 4.3.2 INPUT FUSE This fuse protects the unit against short circuits and over loading. The 20A fuse of type 'F' is used for line input range 95Vac to 264Vac. 4.3.3 DC OUTPUT TERMINALS VSP models with upto 30 amp output ratings have a pair of 5mm brass studs is provided on the rear panel. Models above 30 amps have bus bars are provided. Output polarity is shown near the terminal. 4.3.4 REMOTE SENSE CONNECTOR 6 Way terminals block is provided for remote sensing and current share option. 1. +S: - Positive Sense terminal for remote sensing. 2. +Output: - Positive DC output terminal. 3. -Output: - Negative DC output terminal. 4. -S: - Negative Sense terminal for remote sensing. 5. NC 6. CS Bus: - Current share bus for parallel operation. 4.3.5 ANALOG INTERFACE CONNECTOR (Reference Fig. 4.1a and 4.1b in back of manual) 25 Pin D type connector is provided for remote analog interface, it is factory set to operate through the front panel controls. Pin no. 1: Pin no. 2: Pin no. 3: Pin no. 4: Pin no. 5: Pin no. 6: Pin no. 7: Pin no. 8: Pin no. 9: Pin no.10: Pin no.11: Pin no.12: Pin no.13: N.C. N.C. VPROGI-1 mA (typical) Current source for voltage programming. VPIN - Input for voltage programming. VPROGR - Resistance programming (0 to 4.85KOhms for full-scale voltage) AGND3 - Common terminal for remote programming. N.C. N.C. IPIN - Input for Current programming. IPROGI- 1mA (typical) Current source for Current programming. IPROGR - Resistance programming (0 to 4.85KOhms for full-scale current) N.C. N.C. 14 Pin no.14: Pin no.15: Pin no.16: Pin no.17: Pin no.18: Pin no.19: Pin no. 20: Pin no. 21: Pin no. 22: Pin no. 23: Pin no. 24: Pin no. 25: 4.3.6 N.C. +12 V- Remote on/off relay supply +ve. AGND3 - Common terminal for remote programming. Remote On/Off - Remote on/off relay. AMX- Output Current monitoring. (Factory set to 0 to 5 volts for full scale) VMX - Output Voltage monitoring. (Factory set to 0 to 5 volts for full scale) AGND3 - Common terminal for remote monitoring. N.C. VPSET - External programming option set for output voltage. VMSET -External-monitoring option set for monitoring the output voltage. IPSET - External programming option set for output current. IMSET - External monitoring option set for current. DIP SWITCH DETAILS. DIP Switch is provided on the rear panel to facilitates remote analog interface as well as local mode interface in the power supply by just changing the switch positions Switch no. 1 & 2 are associated with voltage programming Switch no. 3 & 4 are associated with current programming Switch no. 5 is associated with 0-5V & 0-10V programming Switch no. 6 is associated 0-5V & 0-10V monitoring Switch no. 7 is Local/RS232 and Analog interface selection Switch no. 8 is associated with remote ON-OFF. 4.3.7 DIGITAL COMMUNICATION INTERFACE (optional) Digital communication interface either GPIB or RS-232 interface can be incorporated with the system as per the order placed. As per the ordered digital communication interface, the slots are available on the rear panel The slide switch no. 7 on 8 pin DIP switch array selects the LOCAL/RS232 or Analog interface & 9 pin D-Type connector is provided on rear panel to connect the unit to PC. NOTE: Refer Chapter 5 For Details Of Digital Communication Interface. 4.4 POWER ON CHECK Keep the DIP switch settings for local mode operation. (Refer to 4.5) After switching ON the unit, the display will show the actual voltage and current at the output if output ON/OFF switch is in pressed position. If the switch is in OFF position then the output voltage goes to 0V & displays zero. Also LED associated with key shows the condition of output. If TRIP LED is ON then display show zero values and LED associated with ON/OFF key remains off. 15 4.5 OPERATING INSTRUCTIONS IN LOCAL MODE These are the instructions for operating the source in local mode. Initially after Power ON Unit work in local mode.In local mode the power supply can be controlled through front panel potentiometers. Also Refer to the settings of 8Way DIP Switch provided on rear panel to operate in Local mode. Switch No. 1 Position On 2 On 3 On 4 On 5 On 6 OFF 7 On 8 On Refer fig. 3.1a for connection details in local & remote interface Normally user can vary the V SET POT to change the output voltage while working in constant voltage mode operation. I SET POT is used to set the output current while working in constant current mode operation. 4.5.1 SET MODE OPERATION IN LOCAL MODE User can view the set parameters using set mode operation before turning the output ON. To enter the SET mode, switch off the ON/OFF switch. When SET key is pressed for the first time then SET LED turns ON and display shows OVP value and OVP POT LED keeps on flashing. In this mode the OVP POT can be used to change the over voltage limit. On pressing the SET key again the display shows the set voltage and VSET POT LED keeps on flashing. In this mode the VSET POT can be used to change the output voltage. On pressing the SET key again the display shows the set current and ISET POT LED keeps on flashing. In this mode the ISET POT can be used to change the output current. Set mode operation ends after pressing SET key fourth time & displays zero if the output on / off switch is off. At any instant, while in set mode, if output on / off switch is pressed the display displays the output voltage & current. 16 4.6 OPERATING INSTRUCTIONS IN ANALOG REMOTE INTERFACE The Remote analog interface is Provided to control the power supply with external analog signals.Before using the interface check the type of digital interface provided with the system. A slide switch no. 7 on 8 pin DIP switch array is provided at the rear panel to bypass digital and front panel pot controls. Ensure the position of slide switch is in off position when operating with external analog controls. When GPIB interface is used then internal adjustment is required to bypass the GPIB interface. Refer to GPIB section of Chapter 6. Following are the positions of switches for the operating the source in remote mode by external analog voltage and resistance. 4.6.1 Voltage Programming Apply the input programming voltage of 0 to 5Volts or 0 to10 Volts between pin 4 & common control pin 6 of 25 pin D type connector for voltage programming & for current programming between 9 & 6 (common control pin) of 25 pin D-Type connector. 8 pin DIP switch on rear panel: Switch No. 1 2 3 Position Off Off Off 4 Off 5 6 7 off 8 On 5 = ON for 0-5V programming 5 = OFF for 0-10V programming 6 = OFF for 0-5V monitoring 6 = ON for 0-10V monitoring Refer fig. 4.1a for remote voltage and current programming and monitoring It also explains load connections required in this mode. Note: Factory set for 0 to 5 volts for full scale output programming and monitoring. 4.6.2 Resistance Programming For resistance programming standard resistor used is 4.85KOhms. Following shows the DIP switch configuration required in this mode & explains the connection of the resistor to the 25 pin D-type connector. 8 pin DIP switch on rear panel: Switch No. 1 2 3 Position Off On Off 4 On 6 = OFF for 0-5V monitoring 6 = ON for 0-10V monitoring 17 5 On 6 7 off 8 On Refer figure 4.1b for external resistance programming 0 to 4.85kohms for full scale voltage and current . It also shows the load connections required in this mode. As shown in the figure for Voltage Control connect the resistance of 4.85 K ohms at pin 4 & common control pin 6 of 25 pin D Type connector & for Current control connect resistance between pin 9 & pin 6 (common control pin) of 25 pin D Type connector. 4.6.3 Remote ON/OFF: A 25 pin D type connector & DIP switch is provided for remote analog interface to the unit. There is 8 pin DIP switch associated with the function of analog interface. SW no. 8 on the rear 8 pin DIP switch is Remote ON/OFF control & must be always on for terminal voltage ON when operated from the local controls. For the remote control keep SW no. 8 OFF and connect switch across pin no. 16 & 17 of 25 pin D type connector. 4.7 OPERATING INSTRUCTIONS IN DIGITAL INTERFACE To enable remote interface, the command for system to enter remote mode must be entered through remote P.C. This will cause the remote LED on front panel to glow; now no key on front panel will be detected. However the display will be updated to indicate the entered value. In GPIB interface proper address must be given. To change the output voltage while working in constant voltage mode operation or to set the output current while working in constant current mode operation, user has just to enter command (as specified in chapter 5) through remote PC. There are simple commands to take the unit either in remote or local mode. The status of the power supply can be easily read using specific commands. The output can be turned ON or OFF as per requirements. Output ON is indicated by ON LED on the front panel. Also the over voltage limit can be set. Whenever the output voltage exceeds this maximum limit the trip condition occurs thereby resetting the output. The command summary is given in detail in chapter 5. 4.8 TRIP INDICATIONS The VSP series power supplies has provision of Over Voltage & Over Temperature protection. If at any time one of these conditions occurs, the unit will be tripped. This means that the output voltage is made to be zero. This condition is indicated by the Trip LED blinking. 4.8.1 RESETTING THE TRIP CONDITION Assess as to why the trip has occurred. Then isolate the fault e.g., over voltage trip condition can be reset by lowering the output voltage than OV trip level & then toggling the input power will reset trip condition. For resetting the over temp condition allow some time for cooling the heat sinks to change the status of thermal switch. 18 Section 5 Maintenance 5.1 INTRODUCTION 5.2 PREVENTIVE MAINTENANCE 5.3 SERVICE INFORMATION 5.1 Introduction This chapter contains the problems that may occur in the field in the event of long use. The procedure to test the unit is explained under the proper section. The individual is advised to use the correct procedure provided for the purpose of operating the particular sequence to set proper voltages and current required to test the proper working of the unit. This unit has few boards and interconnections and the reliability is very high. However, if a failure occurs the user himself might be able to fix the unit by following the remedies given under particular complaint. Read the manual completely in order to understand your unit better. 5.2 Preventive Maintenance Please follow the following preventive steps to ensure the proper operation of your instrument. * Allow enough natural cooling (ventilation) around the unit. * Avoid keeping tools, equipment etc. on the top cover. * Keep the working area neat and clean always. * Do not exceed the input/output limits at any time. 5.3 Complaints and Service Information Some of the common problems that may occur and the remedy to put back the instrument back in to a working condition as fast as possible are given below: 19 When the unit is not turning ON. Check if the power ON/OFF switch is turned ON. Check whether fuse mounted on the rear panel is OK? If fuse is good then check the power cord. Please make sure that the power cord connecting to the unit is properly connected. Please also check the mains switch. Check the switch 8 on rear panel, it must be always in ON position for terminal voltage ON. When the Trip LED turns On and output turns OFF Check the settings of the over voltage potentiometer. It should not be less than the output set potentiometer. Check the loads at the output. Check whether the temperature inside the unit is not increased abnormally. No Voltage Output available at the output Terminal The possibility is that the Output module itself has failed. The output series pass section may be faulty, therefore check the series pass device & control IC. No display on the front panel meters Check the input conditions and the actual output on the terminals. If it is OK, then the supply to the meters may not be proper or displays may be damaged. Further service information is provided in "Service Information" located at the end of this instruction manual. 20 Section 6 Remote interface 6.1 INTRODUCTION 6.2 RS232C INTERFACE 6.3 RS232C OPERATION 6.4 IEEE-488 OPERATION 6.5 INTRODUCTION TO SCPI LANGUAGE 6.6 COMMAND SUMMARY 6.7 MANDATORY COMMANDS 6.8 INSTRUMENT COMMANDS 6.9 IEEE-4888 COMPLIANCE INFORMATION 6.10 SRQ HANDLING DETAILS 6.11 ERROR MESSAGES & REPORTING 6.12 APPLICATION PROGRAM EXAMPLES 6.1 Introduction VSP series power supplies are configured for either RS232C or GPIB as per the order placed (refer chapter 1 for ordering information). When the unit is first TURNED ON it will enter into LOCAL mode of operation. If the unit is configured for RS232 interface, then by proper slide switch setting & by connecting a serial port of P.C to 9- pin D-type connector on rear panel of the unit, executing RS232 interface commands can operate the power supply. If the unit is configured for GPIB interface, proper address settings are required. Standard commands, which are defined in following sections, through remote PC can operate the power supply. Following sections cover each interfaces separately & explains the operations, configurations & commands of each interface. To use any of the digital interfaces mentioned above, proper setup is required. For RS232 interface setup requirement is a PC with functioning serial port whereas for GPIB interface PC with functioning parallel port is necessary. 21 6.2 RS232C INTERFACE: The basic principle of RS232C operation is achieved by 3-wire interface. The 3-wire interface comprises of transmit pin (abbreviated as TXD), receive pin (abbreviated as RXD) and a common ground pin (GND). TXD pin of host is connected to the RXD pin of the instrument and the RXD pin of the host is connected to the TXD pin of the instrument and the third line connects the GROUNDs of the two sides. I.e. the TXD and RXD lines are cross-connected to the Host controller. Hardware HANDSHAKE lines are not used. The RS232 communications is based on the SEND and RECEIVE signals only. It does not provide the handshaking protocol. The instrument is designed to receive all data without missing any of them with the baud rate specified. Standard baud rate being 9600. The host or the controller (Central Computer) should take care to read the data at the same speed of the instrument as defined by the baud rate. The following communication parameters are FIXED for this particular instrument when operating in the RS232C mode. : POWER ON BAUD RATE CHARACTER LENGTH STOP BITS PARITY HANDSHAKING 6.3 9600 BAUD 8 BITS 1 BIT NO PARITY NO HANDSHAKING RS232C Operation The default communication parameters for RS232C are as follows: 1) BAUD RATE: The default baud rate is 9600 Baud. At present the provision for changing the baud rate in LOCAL mode is not available. 2) CHARACTER LENGTH: The character length is 8 BITS. This is also fixed and cannot be changed by instrument commands. 3) STOP BITS: The instrument generates 1 stop BIT after each character transmission and checks for the same during reception. This parameter is also fixed. 4) PARITY: No PARITY checking is provided. This default configuration is also fixed. 5) HANDSHAKING: No HANDSHAKING is provided. So the host can send all the data at the defined baud rate. And at the same time it should be ready to receive the data or response without any delay. 22 6.3.1 RS232 Data Format One Start Bit 6.3.2 8 Data Bits No Parity Bit 1 Stop Bit RS232 Connector Details On the rear panel of the unit, a 9 pin D-type male connector is provided for the RS232 communication. The DSR and DTR handshake lines are not used. But the interface cable which connects the COMM INTF on the instrument to the PC COM port (COM 1 or COM 2) should interconnect the RXD and the TXD line, such that the RXD input the instrument is the TXD output of the host controller or PC. Swapping is done internally to avoid confusion in the connection. The connector definition of the `COMM INTF' (as marked on the rear panel) are given below: PIN NUMBER DESCRIPTION PIN 2 Receive Data (RXD) PIN 3 PIN 5 Transmit Data (TXD) Ground (GND) Fig. 6.1 Since the RS232 communication does not use the handshaking the DSR input of the controller should be tied up to a signal that is always TRUE. However this implies that your BUS CONTROLLER must always be ready to accept the data. So the interface cable has to be a customized one. Refer fig 6.1. 23 6.3.3 INSTALLATION OF RS232 CARD The RS232 Interface (ISO_RS232_CONV-1103 Card) card may come already installed, if ordered. If this interface is to be installed later, the card can be mounted on the rear panel of the unit using L-clamp provided on the card itself & following cards &cables shall be provided along. Cards: ISO_RS232_CONV-1103 VSP-FP-DAC-1003 Cables: 3 PIN serial communication (Tx, Rx) data cable (J10) on ISO_RS232_CONV-1103 +10V supply cable to be connected on 3 PIN connector (J3) on ISO_RS232_CONV-1103 Following is the procedure to install the card. : Release the TOP COVER of the unit by unscrewing 6 screws at the top & 6 screws at the side panel of the unit. Remove the TOP COVER (upper plate) of the unit by sliding it out. You will see a number of cards inside the unit. Please do not touch any of these. Remove the existing communication card / Connector, which is connected to the slot at the back of the unit marked as `DIGITAL INTF'. Fit the card "ISO_RS232_CONV-1103" on the rear panel of the unit using L-clamp provided on the card itself. Check if the link at JP1 is open Initially disconnect the 26-pin cable from J4 on "VSP-DPM CONT1003" card. Insert the card "VSP-FP-DAC-1003" onto the "VSP-DPM CONT-1003" such that 16-pin DIL female (J3) & 26-pin DIL female (J1) on "VSP-FP-DAC-1003" are plugged in 16-pin DIL male (J7) & 26-pin DIL male (J4) on the "VSP-DPM CONT-1003" card respectively. Now connect the 26-pin flat cable, which was removed from J4 on "VSP-DPM CONT1003" to the 26-pin DIL male (J2) on "VSP-FP-DAC-1003" card. So now the 26-pin DIL male (J1) on "VSP-POT-IMON-0703 "is connected to 26-pin DIL male (J2) on "VSP-FPDAC-1003" card. Do not change the connection between 26-pin DIL male (J2) on "VSP- POT-IMON-0703 " & 26-pin DIL male (J6) of "VSPDDC-1.2KW-1003D" Connect 3-pin SIL connector (J3) on "VSP-POT-IMON-0703" to the 3-pin SIL connector (J2) on "ISO_RS232_CONV-1103" card, which is connected to the switch on rear panel, which decides to select either remote or RS 232 interface. Two connectors are connected to 4-pin SIL connector (J2) on the "VSPDDC-1.2KW1003D" one of which is 4-pin SIL connector (J4) on "VSP-POT-IMON-0703" & other is 3pin SIL connector (J3) on "ISO_RS232_CONV-1103" card Using 3-pin SIL connector connect J10 of on the "ISO_RS232_CONV-1103" card with J10 on "VSP-DPM CONT-1003" card, which are the Transmit & receive signals along with common ground signal. Verify the signal connections again & select RS232 Interface using slide switch provided on rear panel. Turn on the unit & test its functionality. Replace the TOP COVER and close the instrument. 24 6.3.4 RS232 Commands Following section deals with the commands set for RS232 interface. It specifies the syntax of each command, which reads the status of power supply or configures it to the requirements of users. NOTE: The command uses following notations <SP> = Indicates Null or space character (20H) <AARD> = Indicates Arbitrary ASCII Response Data <NR.DATA> = Indicates Numeric Data <EOS> = Indicates End of string character (ODH) 1. Command : READ? <EOS> Description: Read Output Voltage and Current Query. Function: This command reads back the output voltage & current of the unit in <AARD> format. The units for Voltage and Current are VOLTS and AMPS respectively. If the unit is in CV (Constant Voltage) or in CC (Constant Current) mode of operation, this status is also indicated on console. The entire response is terminated with <EOS> byte. For example if the Query sent is READ? <EOS> Then the response can be as follows: +14.99V 00.02A CV<EOS> or +14.00V 10.00A CC<EOS> 2. Command : VOLT<SP><NR.DATA><EOS> Description: Set the Output Voltage for that Channel(s). Function: This command sets the Output Voltage of the Power Supply output with the <NR.DATA> given in the command in Volts. The input VOLTAGE data is in Numeric Data format. For example to set 10.5 Volts then send the command as VOLT 10.50<EOS> 3. Command : CURR<SP><NR.DATA><EOS> Description: Set the Output Current Limit for that Channel(s). Function: This command sets the Output Current of the Power Supply output with the <NR.DATA> given in the command in AMPS. The input CURRENT data is in Numeric Data format. For example to set 2.3 Amps send the command as CURR 02.30<EOS> 25 4. Command: VOLT: PROT<SP><NR.DATA><EOS> Description: Set Over Voltage Protection Limit of OUTPUT Function: This command sets the Over Voltage Protection Limit of the Power Supply output with the <NR.DATA> given in the command in Volts. The input VOLTAGE data is in Numeric Data format. Once this OVP limit is set, any time if the actual Output Voltage of the channel exceeds the OVP limit, the OUTPUT will be `TRIPed'. I.e. the OVP operates to protect the output and the O/P voltage will be made zero and the OUTPUT ON/OFF relay will be switched OFF. For example to set OVP of 31.50 V for output, send the command as VOLT: PROT 31.50<EOS> 5. Command : OUTP<SP>ON<EOS> Description: Turn ON the output of power supply. Function: This command is used to make the OUTPUT available at the output terminals. 6. Command : OUTP<SP>OFF<EOS> Description: Turn OFF the output of power supply. Function: This command is used to switch OFF the output & thus to make the OUTPUT zero at the output terminals. 7. Command : SYST: REM<EOS> Description: Takes the instrument into Remote Mode of operation Function: This command will explicitly take the unit to remote mode. All the front panel controls are disabled. 8. Command : SYST: LOC<EOS> Description: Take the instrument to Local mode of Operation. Function: This command will take the unit to Local mode of operation & ALL the front panel controls are enabled. 26 9. Command : STAT? <EOS> Description: Read Status Query. Function: This command reads the status of various events occurred in the system. The definition of events is given below B0: B1: B2: B3: B4: B5: B6: B7: Over voltage Trip Over Temperature Trip Power On event (Sets when unit is turn ON. The bit gets cleared after the quarry.) Internal Failure Always 1 (THIS STATUS BIT MAY BE CHANGED IN FUTURE) Always 1 (THIS STATUS BIT MAY BE CHANGED IN FUTURE) Command Error (Sets if invalid command received by unit. The bit gets cleared after the quarry.) Always 0 The response to the quarry is single character followed by EOS. For example after power On condition the response to the quarry STAT? Will be 4<EOS>. If Over voltage trip condition occurs then the response will be 1<EOS>. 6.4 IEEE-488 OPERATION: The IEEE-488 (GPIB) interface option allows the instrument to connect and form part of an Automated Test System. The instruments are instructed over a Parallel Data Bus, so that their facilities can be selected remotely. The ADDRESS concept, Parallel Data Bus and Handshaking are the main advantages over the RS23C interface, by which at a time more than one instrument (up to 31 instruments) can be connected on the IEEE-488 bus and only the Addressed instrument can be made to LISTEN or TALK without losing any data. The communication will be faster because of parallel data transfer. The IEEE-488 bus has standard 24 PIN flat cable, in which each line is dedicated to a special BUS activity. The CONTROLLER can send messages or receive responses from all or any one instrument by proper BUS activation and handshaking. 27 6.4.1 IEEE-488 Interface Configuration The IEEE-488 Interface is a parallel BUS for Communication in the Programmable Instruments. Multiple instruments can be connected on the same BUS and can be hooked up to a single HOST controller or computer. In order that instruments from different manufacturers can be built into the same system, it was necessary that all interfaces be compatible. To ensure this, the interfaces were made to conform to a standard specification as detailed in the publication ANSI/IEEE Std. 4881978 called `IEEE Standard Digital Interface for Programmable Instrumentation' (And also to ANSI/IEEE std.488.1-1987) and this came to be known as IEEE-488 or GPIB Interface. The following list highlights the salient characteristics of the IEEE-488 Interface: DATA RATE 1 MB/Sec. MAX. NO. OF DEVICES 31 MAX. BUS LENGTH 20 Meters. MAX. DATA LENGTH 8 BITS / 1 BYTE 28 6.4.2 IEEE-488 Connector Details The instrument provides a standard 24 pin GPIB connector (marked as COMM INTF on the rear panel of the instrument) to connect it with the standard GPIB (IEEE488) bus. Refer FIG. 6.3 for connector types definition diagram. Description of the GPIB Signals is given below. PIN NO. 1 2 3 4 5 6 7 8 9 10 11 12 NAME DIO 1 DIO 2 DIO 3 DIO 4 EOI DAV NRFD NDAC IFC SRQ ATN SHIELD 13 14 15 16 17 18 19 20 21 22 23 24 DIO 5 DIO 6 DIO 7 DIO 8 REN GND 6 GND 7 GND 8 GND 9 GND 10 GND 11 LOGIC DESCRIPTION Data Input Output Line 1 Data Input Output Line 2 Data Input Output Line 3 Data Input Output Line 4 End or Identify Data Valid Not ready for Data Not Data Accepted Interface Clear Service Request Attention Screening on cable (connected to Instrument Safety Ground). Data Input Output Line 5 Data Input Output Line 6 Data Input Output Line 7 Data Input Output Line 8 Remote Enable Gnd wire of twisted pair with DAV. Gnd wire of twisted pair with NRFD. Gnd wire of twisted pair with NDAC. Gnd wire of twisted pair with IFC. Gnd wire of twisted pair with SRQ. Gnd wire of twisted pair with ATN. GND Instrument Logic Ground. TABLE 6.1 29 6.4.3 IEEE-488 Operational Sequence Guidelines Most interface communication tasks require a sequence of coded messages to be sent over the interface. It is recommended that a careful study of the available controller capabilities be made many of them assigning one programming instruction to these sequences. Different controllers will not necessarily have identical sequences or program instructions. The following sequences are recommendations only. DATA TRANSFER ATN DATA FUNCTION 1 1 UNL (LAD) 1 (LAD) n 0 (TAD) Inhibits all current listeners 1Each address sent enables a specific device re ceives future data bytes More than one address may be sent if multiple listeners desired. The address sent enables a specific device to send data 0 (DAB) 1 UNT UNL LAD TAD DAB UNT = = = = = Data bytes sent by currently enabled talker to all currently enabled listeners. Disables the talker on receipt of last character. Unlisten Listen address of specific device Talk address of specific device Data bytes Untalk SERIAL POLL ATN DATA FUNCTION 1 1 UNL SPE 1 (LAD) n 0 (TAD)n Prevents other devices listening to status sent Puts interface into serial poll mode during which all devices send status instead of data when addressed. More than one address may be sent if multiple listeners desired. Enable a specific device to send status. Within these loop devices should be sequentially enabled. 1 SBN or SBA 1 1 SPD UNT Status byte sent by enabled device. If SBN sent, loop should be repeated. If SBA sent, the enabled device is identified as having sent SRQ over the Interface and will automatically remove it. Disables Serial Poll mode Disable Last Talker. 30 UNL SPE SPD SBN SBA 6.4.4 = = = = = Unlisten Serial Poll Enable Serial Poll Disable Status Byte Negative, where BIT 6 = 0 (BIT 7 is the MSB) Status Byte Affirmative, where BIT 6 = 1 (BIT 7 is the MSB) Installation procedure for GPIB interface option in the VSP series power Refer to the general assembly layout of the VSP series power supplies. In the standard units RS232 interface is provided by default. Accordingly, at the location no. 12 the RS232 interface card (ISO-RS232 CONV-0304A) is installed. Also the control card required for GPIB option (SBC-IEB-0504A) is not installed at location no. 18. The connectors required for its control supply are secured on the spacers provided for mounting. The GPIB installation kit contains the following cards and the cables. 1)GPIB control card: SBC-IEB-0504A - 1 No. 2)GPIB interface card: INSTR- TO - GPIB - 1188 3)26 pin FRC cables: 2 no. 4)16 in FRC cable: 2 no. Following procedure should be followed for the GPIB option installation: 1) Remove the top cover of the unit in which the GPIB option needs to be installed by unscrewing the mounting screws. (3 screws on each side and 6 screws on the top) Please do not remove the screw provided for the top cover earthing on the rear top of the cover. Remove the spade connector provided for top cover earth connection, after removing the cover to take it out. 2) Refer to general assembly drawing for the detailed description of the cards inside the unit. 3) Remove RS232 interface card (ISO-RS232 CONV-0304A) at the location no.12. (2 screws from the rear panel and one from the top) 4) Remove VSP-DAC-CONV-0604A, at the location no. 20 by removing the `L' type clamp provided in the new version units or by removing the cable tie in the old version unit. 5) For serial interface (RS232), the micro-controller on the front panel control board is served as the main controller accordingly it is flash programmed. For GPIB option, the SBC - IEB -0504A card has an EPROM with the main program burned in. The controller on the front panel control board is served as slave controller for displaying the control parameters. Accordingly, it needs to reprogram for the same. Please follow the procedure for reprogramming. 6) Reprogramming of front panel control PCB for GPIB option: a) Make sure that the folder named msp_vsp_gpib exists in the pc where the IAR embedded workbench is installed. b) Connect the JTAG connector to J1 of VSP-DPM-CONT-1204D (location no. 9). Please make sure that pin no. 1 of female connector (16 pin) corresponds to pin no. 1 of male connector (14 pin). c) Run IAR embedded workbench. d) Open the project named VSP_INTG from the msp_vsp_gpib folder. e) Select the correct path for GEN.xcl (d:msp_vsp-gpib\gen.xcl). 31 f) Compile the project. g) Connect line input to the unit. Keep the front panel output ON/OFF switch in OFF position. Turn the unit on with the input `Line' switch. h) Run CSPY to download program in flash memory of the controller. i) j) Press the RESET button in the window and exit from CSPY. Turn OFF the unit & remove JTAG connector. This will complete the software installation for GPIB option. 7) Again turn the unit ON & confirm the polarity of the supplies on the supply connector provided for GPIB option. (At 3 pin connector connected to J7 of SBC-IEB-0504A, Pin no. 1 is + ve, pin no. 2 is common and pin no. 3 is -Ve supply. The Voltage is approximately 10 Volts. At 4-pin connector connected to J5 of SBC-IEB-0504A, Pin no. 1 is + ve and pin no. 4 is -Ve supply. The Voltage is approximately 10 Volts. ) Turn The unit OFF. 8) For the GPIB option, there is provision of the jumper links on the VSP-DPM-CONT1204D for the hardware correction. Remove JP6 near IC U4 (This will disconnect the +5V supply presently sourced from display board). 9) Remove jumpers JP2, JP3, JP4 & JP5. (This will isolate CV, CC, OVP and OT signals from connector J4) 10) Install jumper JP1 for GPIB mode. (By default, this jumper is open and need to install in GPIB option). 11) Mount the INSTR-TO-GPIB-1188 pcb on the location 12 with the rear 2 screws. 12) Before mounting the SBC-IEB-0504A pcb make sure that FRC connectors provided for interconnection are placed according to following table. Also place the insulation paper below the pcb & route the cables below the pcb. 13) Sr. No. 01 Cable Type 26 Pin FRC (Long) Connector No. on SBC-IEB-0504A PCB To J6 J1 of INSTR-TO-GPIB-1188 02 26 Pin FRC J8 J1 of VSP-POT-IMON-0604A (Location no. 19) 03 16 Pin FRC J2 J7 of VSP-DPM-CONT-1204D 04 16 Pin FRC J3 J5 of VSP-DPM-CONT-1204D 05 3 Pin SIL J7 Existing in the unit wired for GPIB option. 06 4 Pin SIL J5 Existing in the unit wired for GPIB option. 14) Please make sure that the pin no. 1 of all the connectors are properly installed to the pin no 1 of destination connector. 15) Now the unit is set for GPIB option. Turn the unit ON with `Line' switch. Display will show the blank digits for a while and after a small delay it is ready to work in the LOCAL mode of operation. 16) Check the GPIB interface with the standard available PCI-GPIB interface software. Turn the unit OFF. 17)Now reconnect the earth connection to the top cover & reinstall the top cover. This will complete the installation of GPIB interface. 32 Remove JP2,JP3, JP4 & JP5 From J3 of SBC-IEB Install JP1 From J2 Remove Jumper Link here. VSP-DPM-CONT To J7 To J5 To J1 of VSP-POT-IMON To J1 of INSTR-TO-GPIB 6.4.5 IEEE-488 Instrument Address Selection The instrument address is set manually using an eight way miniature switch near the interface connector on the rear panel. This DIP switch is normally marked with A0 to A7 to identify the proper switch. In our system, we refer A0 as switch 1 and an A7 as switch 8. The OPEN (OFF) condition of the switches will simulate logic 1 and CLOSE (ON) condition will simulate logic 0. These states are marked on the panel as ON (0) and OFF (1). Five of the switches (A0 to A4) are used to set the address using the binary code. This enables any address in the range 00 (00 HEX) to 31 (1F HEX) to be used. E.g. 11010 is address 26 (1A HEX). The switch no A5 is not used. The remaining two switches (A6, A7) are used to say whether the installed IEEE-488 Interface card has to be honored or not. In easy terms, if switches A6 and A7 are CLOSED (ON) simultaneously, the installed IEEE-488 Interface card is ENABLED. If switches A6 and A7 are not simultaneously CLOSED (ON), then the IEEE-488 Interface card will be DISABLED even if the address is set properly. NOTE: THE CONFIGURATION OF IEEE-488 INTERFACE CARD AND THE ADDRESS SETTING OF THE INSTRUMENT HAS TO BE DONE BEFORE THE INSTRUMENT IS SWITCHED ON. AFTER POWER ON, CHANGING OF THE SWITCH SETTINGS ON THE IEEE-488 INTERFACE CARD WILL NOT HAVE ANY EFFECT ON REMOTE OPERATION OF THE INSTRUMENT. 33 ADDRESS SWITCHES SWITCHES A4 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 A3 0 0 0 0 0 0 0 0 1 1 1 1 1 1 1 1 0 0 0 0 0 0 0 0 1 1 1 1 1 1 1 A2 0 0 0 0 1 1 1 1 0 0 0 0 1 1 1 1 0 0 0 0 1 1 1 1 0 0 0 0 1 1 1 A1 0 0 1 1 0 0 1 1 0 0 1 1 0 0 1 1 0 0 1 1 0 0 1 1 0 0 1 1 0 0 1 5-BIT DECIMAL CODE A0 0 1 0 1 0 1 0 1 0 1 0 1 0 1 0 1 0 1 0 1 0 1 0 1 0 1 0 1 0 1 0 00 01 02 03 04 05 06 07 08 09 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 HEX CODE 00 01 02 03 04 05 06 07 08 09 0A 0B 0C 0D 0E 0F 10 11 12 13 14 15 16 17 18 19 1A 1B 1C 1D 1E TABLE 6.2 The Other three switches (A7 A6 A5) must be kept to 000 (ON, ON, ON). 34 6.4.6 Special Notes For the Controller Software Writer This section will provide some valuable hints to the controller software program writer for interfacing this Programmable Unit, through the communication interface. 1). Normal communication is in ASCII. The unit will accept both the lower case and upper case characters. 2). All commands for the units are in the IEEE-488.2 and SCPI format. 3). All mandatory commands for IEEE-488.2 are implemented in the unit. 4). Also the command has to be sent with proper terminator (The Program Message Terminator is either = 0AH (NEWLINE) OR EOI message OR both of the above). Else the command processing will not start. 5). For the responses of query commands, the Response Message Terminator or EOS character will be OAH (New Line) character. 6). For all commands <AARD> means Arbitrary ASCII Response Data and <NR.DATA> means Numeric Data. 7). For wrong commands, the command error bit will be set & an error message is put into Error Queue. 8). Unit will go to remote mode for all valid commands. Queries will not force the unit into remote mode. 9). The GPIB `GTL' command will send the unit into Local mode. 10). IEEE-488 device clear commands `SDC' & `DCL' will generate a communication soft reset to the unit. Present communication buffer will be flashed out. But, the unit will maintain the last settings. 11). When the unit has received MLA (My Listen Address) with REN line true, it will go to remote mode as per the RL2 function requirements. 12). The unit provides complete SRQ function. Refer section 5.10 for details. When the controller polls the SRQ response byte, it is found in case of some controllers that this response byte gets latched in the controllers data in buffer causing an extra character while reading the next message through GPIB. So, it is advisable to give a dummy listen to the controller GPIB controller chip with sufficient time-out to flash out such character if pending any. 35 13). Before sending the unit into talk mode it is also advisable to Flush out the controller's data-in buffer by giving a dummy read. This is required because some controller can keep the last data latched into its data-in Buffer. 14). If you send more than one query in a <PROGRAM MESSAGE>, only the LAST correct query will be processed and response will be given for last query. 15). No response can be read without giving a query. Otherwise the query error bit will be set & an error message is generated. 6.5 An Introduction to SCPI Language Standard Commands for Programmable Instruments (SCPI) defines how you communicate with an instrument from a BUS controller. The SCPI language uses a hierarchical structure similar to the file systems used by many bus controllers. The command "TREE" is organized with root-level commands (also called "SUBSYSTEMS") positioned at the top, with multiple levels below each root level command. You must specify the complete path to execute the individual lower-level commands. USING A COLON (:) When a colon is the first character of a command keyword, it indicates that the next command mnemonic is a root-level command. When a colon is inserted between two-command mnemonics, the colon moves the path down one level in the present path (for the specified root-level command) of the command tree. You must separate the command mnemonics from each other using a colon. You can OMIT the leading COLON if the command is the first of a new program line. USING A SEMICOLON (;) Use a semicolon to separate two commands within the same command string. The semicolon does not change the present path specified. For example the following two statements are equivalent. : SOURce:VOLTage 10.55:SOURce:CURRent 2.50 : SOURce: VOLTage 10.55;CURRent 2.50 USING A COMMA (,) If a command requires more than one parameter, you must separate the adjacent parameters using a comma. 36 USING WHITESPACE You must use Whitespace characters, [tab], or [space] to separate a parameter from a command keyword. Whitespace characters are generally ignored only in parameter lists. USING "?" COMMANDS The BUS controller may send commands at any time, but an SCPI instrument may only send responses when specifically instructed to do so. Only QUERY com mands (commands that end with a "?") will instruct the instrument to send a response message. Queries return either measured values or internal instrument settings or some ERROR messages. CAUTION IF YOU SEND MORE THAN ONE QUERY COMMAND WITHOUT READING THE RESPONSE FROM THE EARLIER ONES, AND THEN ATTEMPT TO READ THE RESPONSE FROM THE LAST QUERY, YOU MAY OR MAY NOT RECEIVE SOME DATA FROM THE EARLIER RESPONSES. BUT YOU WILL RECEIVE COMPLETRESPONSE FOR THE LAST QUERY. TO AVOID THIS DO NOT SEND A NEXTQUERY COMMAND BEFORE READING THE RESPONSE FROM THE FIRST ONE. USING "*" COMMANDS Commands starting with a "*" are called Common Commands (Mandatory commands for IEEE-488.2). They are required to perform the identical function for all instruments that are compliant with the IEEE-488.2 Interface Standard. The "*" Commands are used to control reset, Self-Test and status operation and reporting in the present instrument. 6.5.1 SCPI Data Types The SCPI language defines the different data formats for use in program messages and response messages. Instrument is flexible listeners and can accept commands and parameters in various formats. However, SCPI instruments are PRECISE talkers. This means that the SCPI instruments will always respond to a particular query in a predefined, rigid format. NUMERIC PARAMETERS: Commands that require numeric parameters will accept all commonly used decimal representations of numbers including optional signs, decimal points and scientificnotation. Special values for numeric parameters like MAXimum, MINimum and DEFault are also accepted. You can also send engineering unit suffixes (M, k, or u) with numeric parameters. If only specific numeric values are accepted, the instrument will automatically round the input numeric parameters. 37 DISCRETE PARAMETERS: Discrete parameters are used to program settings that have a limited number of values (like BUS, EXTernal, NORmal, and INVerted). They have a short forms and a long form just like command keywords. You can mix upper case and lower-case letters. Query responses will always return the short form in upper-case letters. BOOLEAN PARAMETERS: Boolean Parameters represent a single binary condition that is either TRUE or FALSE. For a false condition the instrument will accept "OFF" or "0". For a true condition this instrument will accept "ON" or "1". When you query a Boolean setting, the instrument will always return a "0" or "1". STRING PARAMETERS: String Parameters can contain virtually any set of ASCII characters. A STRING must begin and end with matching quotes, either with a single Quote or with a double quote. You can include the quote delimiter as part of the string by typing it twice without any characters in between. 6.5.2 Input Message Terminators Program Messages sent to an SCPI instrument must terminate with a < NEWLINE > character. The IEEE-488 EOI (END OR IDENTITY) signal is interpreted as a < NEWLINE > character and may also be used to terminate a message in place of the < NEWLINE > character. Many programming languages allow you to specify a message terminator character or EOI state to be automatically sent with each BUS transaction. Message termination will always set the current path back to the root-level. 6.5.3 SCPI Goals The goal of Standard Commands for Programmable Instruments (SCPI) is to reduce Automatic Test Equipment (ATE) program development time. SCPI accomplishes this goal by providing a consistent programming environment for instrument control and data usage. This consistent Programming environment is achieved by the use of defined program messages, instrument responses and data formats across all SCPI instruments, regardless of manufacturer. The advantage of SCPI for the ATE system programmer is reducing the time learning how to program new SCPI instruments after programming their first SCPI instrument. By providing a consistent programming environment, replacing one SCPI instrument with another SCPI instrument in an ATE system will usually require less effort than with non-SCPI instruments. 38 6.5.4 SCPI Status Model All SCPI instruments implement status registers in the same way. The status system records various instrument conditions in three register groups: The Status Byte register The Standard Event register and The Questionable Data register. The status byte register records high level summary information reported in the other register groups. The diagram on the next page illustrates the SCPI status system. Event Registers: The standard and the questionable data registers have event registers. An event register is a read-only register that reports defined conditions within the instrument. Bits in the event registers are latched. Once an event bit is set, subsequent state changes are ignored. Bits in an event register are automatically cleared by a query of that register (such as *ESR? or STAT: QUES: EVEN?) or by sending the *CLS (clear status) command. A reset (*RST) or device clear will not clear bits in event registers. Querying an event register returns a decimal value, which corresponds, to the binary weighted sum of all bits set in that register. Enable Registers: An enable register defines which bits in the corresponding event register are logically Ored together to form a single summary bit. Enable registers are both readable and writable. The *CLS (clear status) command does not clear enable registers but it does clear the bits in the event registers. The STATus:PRESet command will clear the questionable data enable register. Querying an enable register will not clear it. To enable bits in an enable register, you must write a decimal value, which corresponds, to the binary weighted sum of bits you wish to enable in a register. 39 SCPI STATUS SYSTEM 40 The Status Byte Register The status byte summary register reports conditions from other status registers.Query data that is waiting in the instrument's output buffer is immediately reported through the "message available" bit (bit 4). Bits in the summary registers are not latched. Clearing an event register will clear the corresponding bits in the status byte summary register. Reading all messages in the output buffer, including any pending queries will clear the message available bit. BIT DEFINITIONS-STATUS BYTE REGISTER BIT VALUE 0 1 2 DESCRIPTION DEFINITION Not Used Not Used Questionable Data DECIMAL 3 4 Not Used Message Available 8 16 5 Standard Event 32 6 Request Service 64 7 Not Used 128 1 2 4 Always set to 0. Always set to 0. One or more bits are set in the Questionable Data register (bits must be "enabled" in enable Register) Always set to 0. Data is available in the Instrument's output buffer. One or more bits are Set in the Standard Event register (bits must be "enabled" in enable regist). The Instrument is requesting the SERVICE (Serial Poll). Always set to 0. The Status byte summary register is cleared when: You execute a * CLS (clear status) command. Querying the standard event and questionable data registers will clear only the respective bits in the summary register. The status byte enable register (request service) is cleared when: * You turn on the power to the instrument. * You execute a *SRE 0 command. USING *STB? TO READ THE STATUS BYTE The *STB? (Status byte query) command is similar to a serial poll except it is processed like any other instrument command. The *STB? Command returns the same result as an IEEE-488 serial poll except that the "request service" bit (bit 6) is not cleared if a serial poll has occurred. The *STB? Command is not handled automatically by the IEEE-488 bus interface hardware and the command will be executed only after previous commands have completed. Polling is not possible using the *STB? Command. Using the *STB? Command does not clear the status byte summary register. 41 TO INTERRUPT YOUR BUS CONTROLLER USING SRQ * * * * * Send a bus device clear message. Clear the event registers with the *CLS (clear status) command. Set the *ESE (standard event register) & *SRE (status byte register) enable masks. Send the *OPC? (Operation complete query) command and enter the result to assure synchronization. Enable your bus controller's IEEE-488 SRQ interrupt. TO DETERMINE WHEN A COMMAND SEQUENCE IS COMPLETED. * * * * * * Send a device clear message to clear the instrument's output buffer. Clear the event registers with the *CLS (clear status) command Enable "operation complete" using the *ESE 1 command (standard event register) Send the *OPC? (Operation complete query) command and enter the result to assure synchronization. Send your programming command string and place the *OPC (Operation complete) command as the last command. Use a serial poll to check to see when bit 5 (standard event) is set in the status byte summary register. You could also configure the instrument for an SRQ interrupt by sending *SRE 32 (status byte enable register, bit 5). HOW TO USE THE MESSAGE AVAILABLE BIT (MAV) You can use the status byte "message available" bit (bit 4) to determine when data becomes available to read into your bus controller. The instrument sets bits 4 when the first reading becomes ready (which can be READ?). The instrument subsequently clears bit 4 only after all messages have been read from the output buffer. The message available (MAV) bit can only indicate when first reading is available following a READ? Or following a *TST? Query command. This can be helpful because you do not know when the Self-Test will be completed after the *TST? Command is given. THE STANDARD EVENT REGISTER The standard event register reports the following types of instrument events: power-on detected, command syntax errors, command execution errors, self-test or calibrationerrors, query errors, or when an *OPC command is executed. Any or all of these conditions can be reported in the standard event summary bit through the enable register. You must write a decimal value using the *ESE (event status enable) command to set the enable register mask. 42 Note: An error condition (standard event register bits 2,3,4 or 5) will always record one or more errors in the instrument's error queue. Read the error queue using SYSTem: ERRor? The standard event register is cleared when: * You send a *CLS (clear status) command. * You query the event register using the *ESR? (Event status register) command. The standard event enable register is cleared when: * * You turn on the power to the instrument. You execute a *ESE 0 command. BIT DEFINITIONS-STANDARD EVENT REGISTER BIT VALUE 0 DESCRIPTION DEFINITION Operation Complete DECIMAL 1 Not Used 2 2 Query Error 4 3 Device Error 8 4 5 6 7 Execution Error Command Error Not Used Power On 16 32 64 128 1 All commands prior to and including an *OPC command have been executed. The instrument tried to read the output buffer but it was empty. Or a new command line was received before a previous query has been read. Or, both the input and output buffers are full. The controller tried to read the O/P buffer of the instrument without giving the Query first or wrong Channel list was supplied in query. A Self-Test, Calibration Or Channel TRIP error occurred. An execution error occurred. A command syntax error has occurred. Always set to 0. Power has been turned off and on since the last time the event register was read or cleared. THE QUESTIONABLE DATA REGISTER The Questionable Data Register provides information about the FAULTS on the different CHANNELS of the Source unit. When a CHANNEL TRIP occurs the reason as to what caused the TRIP on that CHANNEL could be obtained from this register. The CHANNEL can have Over Voltage trip or Over Current trip or Over Temperature trip. Any or all of these conditions can be reported in the questionable data summary bit through the enable register. You must write a decimal value to enable that particular event using the command STATus: QUEStionable: ENABle < DATA > 43 BIT DEFINITIONS-QUESTIONABLE DATA REGISTER BIT VALUE 0 2 3 5 6 7 8 10 11 13 14 15 DESCRIPTION DEFINITION OVP trip OT trip OVP trip OT trip Not Used Not Used OVP trip OT trip OVP trip OT trip Not Used Not Used DECIMAL 1 4 8 32 64 128 256 1024 2048 8192 16384 32768 Channel 1 Over Voltage Trip Channel 1 Over Temperature Trip Channel 2 Over Voltage Trip Channel 2 Over Temperature Trip Always Set to 0 Always Set to 0 Channel 3 Over Voltage Trip Channel 3 Over Temperature Trip Channel 4 Over Voltage Trip Channel 4 Over Temperature Trip Always Set to 0 Always Set to 0 The questionable data event register is cleared when: * You execute a *CLS (clear status) command. * You query the event register using STATus: QUEStionable: EVENt? The questionable data enable register is cleared when: * You turn on the power to the instrument. * You execute the STATus: PRESet command * You execute the STATus: QUEStionable: ENABle 0 command. 6.6 COMMAND SUMMARY This section summarizes the SCPI commands available for this Programmable Instrument. Refer to the later sections in this chapter for more complete details on each command. Throughout this manual, the following conventions are used for SCPI command syntax. Square brackets ([ ]) indicate optional keywords or parameters. Braces ({}) enclose parameters within a command string. Triangle brackets (< >) indicate that you must substitute a value for the enclosed parameter. 44 SR NO. 1 2 3 4 5 6 7 8 9 10 11 12 13 IEEE-488.2 COMMON COMMANDS *CLS *ESE<SP><NR.DATA> *ESE? *ESR? *IDN? *OPC *OPC? *RST *SRE<SP><NR. DATA> *SRE? *STB? *TST? *WAI SR NO. 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 STATUS REPORTING COMMANDS SYSTem: ERRor? STATus: QUEStionable: EVENt? STATus: QUEStionable: ENABle? STATus: QUEStionable: CONDition? STATus :QUEStionable:ENABle<SP><NR.DATA> STATus: OPERation: EVENt? STATus: OPERation: ENABle? STATus: OPERation: CONDition? STATus:OPERation:ENABle<SP><NR.DATA> STATus:PRESet *CLS *ESE<SP><NR.DATA> *ESE? *ESR? *OPC *OPC? *SRE<SP><NR.DATA> *SRE? SR NO. 1 2 3 4 5 6 7 8 SYSTEM RELATED COMMANDS READ? [SOURce:] VOLTage<SP><NR.DATA><Channel_list> [SOURce:] CURRent<SP><NR.DATA> <Channel_list> [SOURce:] VOLTage:LIMit<SP><NR.DATA><Channel_list> [SOURce:] VOLTage:PROTection<SP><NR.DATA> <Channel_list> OUTPut[:STATe]<SP>ON<Channel_list> OUTPut[:STATe]<SP>OFF<Channel_list> 45 NOTE: <SP> <AARD> <NR.DATA> <EOS> <Channel_list> 6.6.1 = Null or space character (20H) = Arbitrary ASCII Response Data = Numeric Data = End of string character (OAH) = Channel Number operation. The format for giving the channel list is (@1) : Channel number 1 (@1,2) : Channel nos. 1 & 2. (@1,2:4) : Channel numbers 1,2,3,4. Brackets are compulsory. SPECIAL NOTES ON THE COMMANDS FOR VSP SERIES: 1). All commands for the unit are in the IEEE-488.2 and SCPI format. 2). All mandatory commands for IEEE-488.2 are implemented in unit. 3). Also the command has to be sent with proper terminator. Else the command processing will not start. 4). For the responses of query commands, the Response Message Terminator or EOS character will be OAH (New Line) character. 5). For all commands <AARD> means Arbitrary ASCII Response Data and <NR.DATA> means Numeric Data. 6). For wrong commands, the command error bit will be set & an error message is put into Error Queue. 7). Unit will go to remote mode for all valid commands. Queries will not force the unit into remote mode. 8). If you send more than one query in a <PROGRAM MESSAGE>, only the LAST correct query will be processed and response will be given for last query. 9). The Channel list in the command is optional for single channel power supply. 10). No response can be read without first giving a query. Otherwise the query error bit will be set & an error message is generated. 11). The local lockout can be set when the instrument is in remote mode of operation. 12). The address of the IEEE-488 interface is default set to 0. 46 6.7 MANDATORY COMMANDS This section explains in detail the IEEE-488.2 and SCPI MANDATORY common commands, which are supported by this Programmable Instrument. NOTE: <SP> <AARD> <NR.DATA> <EOS> <Channel_list> = Null or space character (20H) = Arbitrary ASCII Response Data = Numeric Data = End of string character (OAH) = Channel Number operation. The format for giving the channel list is (@1) : Channel number 1 (@1,2) : Channel nos. 1 & 2. (@1,2:4) : Channel numbers 1,2,3,4. Brackets are compulsory. 1. Command : Description : Function : *CLS Clear Status command This will clear status Data Structure & forces the Instrument to OCIS and OQIS state. 2. Command : Description : Function : *ESE<SP><NR.DATA> Standard Event Status Enable command. This <NR.DATA> is from 0-255 & will set or reset the bits of Standard Event Status Enable Register. 3. Command : Description : Function : *ESE? Standard Event Status Enable Query This query command reads the contents of Stan dard Event Status Enable register in < NR.DATA>(0255) data format. 4. Command : Description : Function : *ESR? Standard Event Status Register Query This query command reads the contents of the Standard Event Status Register in <NR.DATA> Numeric Data (0-255) format. 47 5. Command : Description : Function : *IDN? Identification Query This query command will read back the specific information about device. There are 4 fields in the response separated by commas. Field 1: Manufacturer (DEL) Field 2: Model number (XXXXXXX) Field 3: Serial number (0 if not available) Field 4: Version number (XX.YY) 6. Command : Description : Function : *OPC Operation complete command This command tells the device to generate the operation complete message in the Standard Event register when all the pending selected device operations have been completed. 7. Command : Description : Function : *OPC? Operation Complete Query When this query is sent if the <NR.DATA> response received is `1', then it implies that the device has completed all pending operations. 8. Command : Description : Function : *RST Reset Command This Reset command performs a Device reset & forces the device into OCIS state & OQIS state and sets the device specific functions to a known state. (Please refer to section 5.7.1 for the Details of *RST Conditions.) 9. Command : Description : Function : *SRE<SP><NR.DATA> Service Request Enable Command. This command sets the bits in the Service Request Enable Register as per the data sent in the <NR.DATA> (0255) data format. 48 10. Command : Description : Function : 11. Command : Description : : This query command reads back the contents of the Status Byte Register in the <NR.DATA> Numeric Data format ranging from 0-255. Command : Description : Function : *TST? Self-Test Query. This query command causes an internal Self Test & reports whether the Test was completed successfully ( <NR.DATA> = 0 ) or detected any of the errors in the Self Test ( <NR.DATA> = non-zero ), which are discussed in detail under section 5.11 of this chapter. Function 12. *SRE? Service Request Enable Query. This query command reads back the contents of the Service Request Enable Register in the <NR.DATA> Numeric data format (0-255). *STB? Read Status Byte Query. NOTE: Before running the Self-Test with the *TST? Command set the OVP and OCP Limits to maximum. Or else the unit will TRIP. 13. Command : Description : Function : *WAI Wait to continue command. This command shall prevent the device from executing any further commands or readings till the No-operation pending Flag is set true. 14. Command : Description : Function : SYSTem: ERRor? System Error condition Query. This command returns the error number & error description from the error queue of the instrument. If the ERROR QUEUE is empty, 0,"No error" will be the response. The error queue can hold up to 6 messages. If the entire buffer is full and an ERROR occurs at this moment then the last message in the Error Queue will be replaced with -350,"Queue overflow" When a message is read from the queue using the SYSTem:ERRor? Query, the first one is cleared and all the messages are shifted one to the start again. 49 15. 16. Command : Description : Function : STATus:QUEStionable:EVENt? Status Questionable Event Register Query. This query command returns the <NR.DATA> format (032767) value of the Questionable Event Register, (16 bit register) specific to instrument, to give the reason for Error. After this QUERY reads the register, the contents of the Status Questionable Data Event Register are cleared. Command STATus:QUEStionable:ENABle<SP> <NR.DATA> Set Enable bits for status Questionable Enable Register. This command takes <NR.DATA> input & puts the corresponding HEX data to status Questionable Enable Register (to enable the corresponding events in Status Questionable Event Register). Since the enable register is also a 16-bit register, the <NR.DATA> can be in the 0-32767 range. If the input data is out of range then an "Execution error" will be generated. : Description : Function : 17. Command : Description : Function : STATus:QUEStionable:ENABle? Read Status Questionable Enable Register Query. This query command reads the contents of the Status Questionable Enable Register, in the <NR.DATA> (032767) format, whose corresponding HEX value represents the bit pattern of the Register. 18. Command : Description : Function : STATus:QUEStionable:CONDition? Read Status Questionable condition register query. This query will give the contents of status questionable condition register in <NR.DATA> (0-32767) format, whose HEX value represents the Bit pattern of the register. This will always read as `0' (ZERO). 19. Command : Description : Function : STATus:OPERation:EVENt? Read Status operation Event Register Query. This query returns the contents of the Status Operation Event register in <NR.DATA> format (0-32767) whose 16 Bit HEX value represents the Bit pattern of register. This will always read as `0' (ZERO). 20. Command STATus:OPERation:ENABle<SP> <NR.DATA> Set the Enable Bits of status operation Enable Register. This command takes <NR.DATA> input and puts the corresponding HEX data to Status Operation Enable Register (to enable the corresponding events in Status Operation Event Register). Since the enable register isalso a 16-bit register, the <NR.DATA> can be in the Description : Function : : 0- 32767 range. If the input data is out of range then an "Execution error" will be generated. 50 21. Command : Description : Function : 22. Command : STATus:OPERation:CONDition? Description : Read Status Operation condition register query. Function : This query will give the contents of Status Operation Condition Register in <NR.DATA> (0-32767) format, whose HEX value represents the Bit pattern of the register. This will always read as `0' (ZERO). 23. Command : Description : Function 6.7.1 : STATus:OPERation:ENABle? Read Status Operation Enable Register Query. This query command reads the contents of the Status Operation Enable Register, in the <NR.DATA> (0-32767) format, whose corresponding HEX value represents the bit pattern of the Register. STATus:PRESet Resets the Enable Bits of Status Operation and Questionable Enable Register. This command puts the data as `0' (ZERO) so that corresponding HEX data (00 Hex) will CLEAR the Status Operation Enable and Status Questionable Enable Registers. (to disable all the corresponding events in the Status Operation Event Register and Status Questionable Data Event Register ). *RST Conditions The following conditions are defined for the PROGRAMMABLE DC POWER SUPPLY on receiving the *RST command and execute it. 6.8 1). The Baud Rate of the instrument for RS232 operation is set to 9600 BAUD, which is variable through Remote mode commands. 2). The output Voltage, Current, OVP Limit and OCP Limit for all the Channels are set to the same values as programmed in the Configuration setup, stored in the EEPROM installed inside the unit. 3). The output ON/OFF relays for all the Programmable Channels are switched to `OFF' position. INSTRUMENT (SYSTEM RELATED) COMMANDS This section explains in detail the Instrument Specific or the System Related Commands, which are used to Program different parameters of the system. All commands, except the last two commands (For selecting the Internal or External SENSE for the output) are SCPI APPROVED commands. But the last two are SCPI CONFIRMED commands. For this instrument there is NO command, which are not part of the SCPI definition. 51 NOTE: <SP> <AARD> <NR.DATA> <EOS> <Channel_list> 1. 2. Command : Description : Function : Command : Description : Function : = Null or space character (20H) = Arbitrary ASCII Response Data = Numeric Data = End of string character (OAH ) = Channel Number operation. The format for giving the channel list is (@1) : Channel number 1 (@1,2) : Channel nos. 1 & 2. (@1,2:4) : Channel numbers 1,2,3,4. Brackets are compulsory. READ?<Channel_list> Read Output Voltage and Current Query. This command reads back the output voltage & current of the unit in <AARD> format. The units for Voltage and Current are VOLTS and AMPS respectively. If the specified CHANNEL(S) is in CV (Constant Voltage) mode of operation, no special indication is given. But if it is in CC (Constant Current) mode of operation then the word `CC` is put at the end of the response. The entire response is terminated with <EOS> byte. Response is in Arbitrary ASCII Response Data format. <Channel_list> indicates for which all CHANNELS the DATA has to be read. The responses of two channels are separated by the RMUS (Response Message Unit Separator), which is SEMICOLON (;). The sequence of the Response for more than one channel is the same as the Sequence of the channel numbers specified in the <Channel_list>. If no such Channel_list> is provided the READ? query will always read from channel 1. For example if the Query sent is READ?(@2,1) then the response can be as follows: +14.99V 00.02A;+00.35V 01.99A CC<EOS> which indicates that CHANNEL 1 is in CC mode. [SOURce:]VOLTage<SP><NR.DATA> <Channel_list> Set the Output Voltage for that Channel(s). This command sets the Output Voltage of the Power Supply output with the <NR.DATA> given in the command in 52 Volts. The input VOLTAGE data is in Numeric Data format. The <Channel_list> above, indicates for which all CHANNELS the DATA has to be SET. The same data will be set on all the specified CHANNEL(S). If no such <Channel_list> is provided the SOURce command will always SET to channel 1. For example to set 10.5 Volts on Channel 2, send the command as: SOURce:VOLTage 10.50(@2) For example to set 30 Volts on Channels 1&2,send the command as: VOLTage 3.00 E+1(@1:2) 3. Command : Description : Function : [SOURce:]CURRent<SP><NR.DATA> <Channel_list> Set the Output Current Limit for that Channel(s). This command sets the Output Current of the Power Supply output with the <NR.DATA> given in the command in AMPS. The input CURRENT data is in Numeric Data format. The <Channel_list> above, indicates for which all CHANNELS the DATA has to be SET. The same data will be set on all the specified CHANNEL(S). If no such <Channel_list> is provided the SOURce command will always SET to channel 1. For example to set 2.3 Amps on Channels 1&2 send the command as: SOURce: CURRent 2.300 E+0(@1,2) For example to set 1 Amp on Channel 1 only, send the command as: CURR 1 For example to set 1.99 Amps on Channel 2, send the command as: SOUR:CURR 199 E-2(@2) 4. Command : Description : Function : [SOURce:]VOLTage:LIMit<SP> <NR.DATA><Channel_list> Set the Upper Limit of O/P Voltage for that Channel(s). This command sets the Soft Upper Limit for Output Voltage of the specified CHANNEL(S) of the Power Supply output with the <NR.DATA> given in Volts. The input VOLTAGE data is in Numeric Data format. The <Channel_list> above, 53 indicates for which all CHANNELS the LIMIT has to be SET. The same data will be set on all the specified CHANNEL(S). Once this limit is set, from that point onwards the output voltage can not be set to higher values than this. If you try to set higher value using SOURce:VOLTage command, the " Execution error " will be generated. At the same time the LIMITS can not be set to a value, which is more than the MAXimum ratings of the CHANNEL(S). Also the read value of Voltage is checked with the Soft Limit Voltage value all the time and if the reading exceeds the Channel will be TRIPPed, giving the reason for TRIP as S/W OVP TRIP. For example to set Limit of 30.80 Volts on Channel 2, send the command as : SOURce:VOLTage:LIMit 30.80(@2) OR VOLT:LIM 3.08 E+1(@2) 5. Command Description : Function : : [SOURce:]VOLTage:PROTection<SP> <NR.DATA><Channel_list> Set Over Voltage Protection Limit for that Channel(s). This command sets the Over Voltage Protection Limit for that CHANNEL of the Power Supply output with the <NR.DATA> given in the command in Volts. The input VOLTAGE data is in Numeric Data format. The <Channel_list> above, indicates for which all CHANNELS the OVP has to be SET. The same data will be set on all the specified CHANNEL(S). If no such <Channel_list> is provided the PROTection command will always SET to channel 1 OVP. Once this OVP limit is set on a channel, any time if the actual Output Voltage of the channel exceeds the OVP limit, the CHANNEL(S) will be `TRIPed'. I.e. the OVP operates to protect the channel and the O/P voltage will be made zero and the OUTPUT ON/OFF relay will be switched OFF. For example to set OVP of 31.50 V on Channel 2, send the command as : SOURce:VOLTage:PROTection 31.50(@2) 54 6. Command : Description : Function : OUTPut[:STATe]<SP>ON <Channel_list> Set the Output relay to ON state for the specified channels. This command is used to switch on the output relay & thus to make the OUTPUT available at the output terminals. 7. Command : Description : Function : OUTPut[:STATe]<SP>OFF<Channel_list> Set the Output relay to OFF state for the specified channels. This command is used to switch OFF the output relay & thus to disconnect the OUTPUT available at the output terminals. 8. Command : Description : Function : SYSTem:REMote Takes the instrument into Remote Mode of operation This command will explicitly take the unit to remote mode. All the front panel controls are disabled. It is advisable to put the unit into REMOTE mode of operation using this command, before using the instrument in Remote mode. 9. Command : Description : Function : SYSTem:LOCal Take the instrument to Local mode of Operation. This command will take the unit to Local mode of operation & ALL the front panel controls are enabled. 6.9 IEEE-488 COMPLIANCE INFORMATION Dedicated Hardware Lines: ATN IFC REN SRQ Attention Interface Clear Remote Enable Service Request Interrupt Universal Commands: ATN Addressed Commands: SDC END GTL Selected Device Clear End Message Go to Local 55 DCL Device Clear Attention IFC Interface Clear LLO Local Lock-Out IEEE-488 INTERFACE COMPATIBILITY : Although the IEEE-488 Interface specification is called a standard, variations in implementation within the specifications are permitted. These variations determine the capabilities of the particular interface and a list of abbreviations are defined in the Standard Document to indicate to the User which Interface capabilities have been designed in. The TABLE 6.3 below gives the options, which are implemented in this instrument. CODE SH1 AH1 T6 TE0 L4 LE0 SR1 RL1 PP0 DC1 DT0 C0 E1 INTERFACE FUNCTION Source Handshake Complete Capability Acceptor Handshake Complete Capability Talker Function.(Basic Talker, Serial Poll, Unaddressed to Talk if Addressed to Listen). No Address Extension Talker Mode Listener Function.(Basic listener, Unaddressed to listen if Ad dressed to Talk). No Address Extension Listener Mode Service Request Complete Capability Remote / Local Complete Capability (Including Local Lock Out). No Parallel Poll Capability. Device Clear Complete Capability (Accepts DCL & SDC commands and generates a communica tion soft reset and flashing out the buffer). No Device Trigger Capability No Controller Capability Tristate driver (Jumper selectable between tristate and open collector). TABLE 6.3 6.10 SRQ HANDLING DETAILS This Programmable Instrument has been configured for SR1 function (Complete SRQ Capability). To make use of this feature you must configure your BUS controller to respond to the IEEE-488 Service Request (SRQ) Interrupt. This unit does not support Parallel Poll capability. THE SERVICE REQUEST ENABLE (SRE) REGISTER The Service Request Enable (SRE) register will enable only those events in the Status Byte Register to generate an SRQ, when the corresponding bit in the SRE register is set to `1'. Thus by writing the required data in the SRE register using the command *SRE<SP><NR.DATA>, the reasons to generate an SRQ can be defined. The following table gives the bit definitions of the Service Request Enable (SRE) Register. 56 BIT DEFINITIONS-SERVICE REQUEST ENABLE (SRE) REGISTER BIT VALUE 0 1 2 DESCRIPTION DEFINITION Not Used Not Used Questionable Data 1 2 4 3 4 Not Used Message Available 8 16 5 6 7 DECIMAL Standard Event 32 Not Used 64 128 Always write with 0. Always write with 0. If this bit is set, an SRQ will be raised when one or more bits are set in the Questionable Data register (bits must be "enabled" in enable Register) Always write with 0. If this bit is written with `1' then an SRQ is raised when the data is available in the Instrument's output buffer. If this bit is written with `1' then an SRQ is raised when one or more bits are Set in the Standard Event register (bits must be "enabled" in enable register). Always write with 0. Always write with 0. The Service Request Enable (SRE) register is cleared when: * You turn on the power to the instrument. * You execute a *SRE 0 command. ENABLING THE SRQ GENARATION: First use the Service Request Enable ( SRE ) Register to select which summary Bits of the Status Byte Register will set the low-level IEEE-488 SRQ Signal. Now write the correct data in the SRE register, for enabling the SRQ reason in the Status Byte Register. For this the command *STB<SP><NR.DATA> can be used.After that the query *SRE? Command will return the same value, which was sent above. Now enable your BUS controller's SRQ interrupt. When the Status Byte Register " REQUEST SERVICE " bit (Bit 6) is set, an IEEE-488 SRQ Interrupt message is automatically sent to the BUS controller. The BUS controller may then POLL the instruments on the bus to identify which one of the instruments has raised the SRQ. The controller asks all the instruments on the BUS to place their SRQ message one by one. The one with Bit 6 SET in its Status Byte Register has requested the SERVICE. Now controller may take necessary action to service or cancel the SRQ. Reading the status byte using an IEEE-488 Serial Poll only clears the "REQUEST SERVICE" bit or by reading the Event Register whose Summary Bit (in the Status Byte) is causing the service request. 57 To read the Status Byte Summary Register, send the IEEE-488 Serial Poll Message. Querying the Summary Register will return a Decimal value, which corresponds, to the binary - weighted sum of the bits, set in the register. Serial Poll will automatically clear the " REQUEST SERVICE " bit in the Status Byte Summary Register. No other bits are affected. Performing a Serial Poll will not affect the instrument functioning. USING SERVICE REQUEST (SRQ) AND SERIAL POLL For example when the Self-Test is performed on this instrument using the command *TST? (using the IEEE-488 Remote interface ), it takes time for the instrument to conduct the test and report the results to the BUS controller. The response will be given at the end of the Self-Test. Here user may have to keep reading from the Output Buffer of the instrument to know the result. But by using the SRQ function one can do this task in a better way as explained below. : 1) Enable your BUS controller's SRQ interrupt. 2) Enable the SRQ reason "MAV" (Message Available Bit) in the Status Byte Register by sending the command as *SRE 16. 3) Send the command *TST? from remote for the Self-Test. 4) Wait till your BUS Controller detects an SRQ on the bus. 5) When an SRQ is detected, poll the SRQ from this instrument to read the SRQ response message as 80 (50 Hex). This means that the RQS bit is set and the MAV bit is set in the Status Byte Summary Register. 6) Now read the Output Buffer of the instrument from your BUS controller to get the Response Message of the Self-Test, which will be a 3 digit decimal number like 620 or 603 and so on. This unit provides complete SRQ function. When the Controller polls the SRQ Message, it is found that in case of some Controllers that this Response byte gets latched in the Controller's Data-out buffer causing addition of an extra character in the next message which is read against some query command. So it is advisable to give a Listen to the Controller Chip with sufficient time-out to flush out such character pending, if any. 6.11 ERROR MESSAGES AND REPORTING This section explains in short the Error Messages, which are stored in the ERROR QUEUE. and are reported when read through the SYSTem:ERRor? . The messages are stored when query command syntax or hardware errors have been detected. A record of up to 6 errors is stored in the instrument's error queue. Errors are retrieved in first-in-first-out (FIFO) order. 58 * No method is available to read the error queue from the front panel menu. * The error queue is cleared when power has been off or after a *CLS (clear status) command has been executed. * To read the error queue from the remote interface, send query as: SYSTem:ERRor? * Errors have the following format (the error string may contain up to 40 characters): -100,"Command error" ERROR QUEUE: As the errors and events are detected, they are placed in the queue. This queue is FIRST IN - FIRST OUT. If the queue overflows, the last error or event in the queue is replaced with the error -350,"Queue overflow" Any time the queue overflows, the least recent errors remain in the queue, and the most recent error or event is discarded. Reading an error from the head of the queue removes that error from the queue, and opens a position at the tail of the queue for a new error, if one is subsequently detected. When all errors have been read from the queue, further queries for this queue will return 0,"No error" till another error is recorded in the error queue. The error or event queue is cleared when any of the following occur: * Upon Power up. * Upon receipt of a *CLS command. * Upon reading the last item from the error queue. COMMAND ERRORS Message: -100,"Command error" An invalid command was found in the command string. You may have inserted a character such as #, $, or % in the command header or within a parameter or you have sent a command which is not supported by the instrument. This error is given for syntax errors, missing parameter, wrong header, and numeric data error etc. 59 EXECUTION ERRORS Message: -200,"Execution error" A valid command could not be executed because of the unrecoverable TRIP condition in the related channel(s) or the numeric data given in the command exceeds the maximum allowed hard limits or the Soft Upper Limits which were set by the Limit commands. In such cases the instrument generates the Execution error. DEVICE-SPECIFIC ERRORS Message: -300,"Device-specific error" A Device specific failure has occurred or some fault is detected on any one or more channels of the instrument. When the CHANNEL is `Tripped because of the Over Voltage Protection, Over Current Protection or Over Temperature Protection, this error is generated. To read the exact cause of the TRIP on that channel the Status Questionable Data Event Register contents have to be read. Message: -330,"Self-test failed" The instruments complete self-test failed from the remote interface (*TST? command). The result of the self-test is separately reported in the response of the *TST? query command. The decimal number, which is in response to the above query, indicates what exactly has failed in the Self-test. Refer to next page for more details. QUERY ERRORS Message: -400,"Query error" A Query error is reported when the controller tries to read the instrument's OUTPUT BUFFER without first, sending the query. For every response to be received, a query command has to be sent first. Also in the READ? query, if the <Channel_list> does not contain any valid CHANNEL number then also the Query error is recorded. 60 Fig 4.1a REMOTE VOLTAGE AND CURRENT PROGRAMMING AND MONITORING Factory Set for 0 to 5 Volts for full scale output programming and monitoring NC NC VPROGI VPIN VPROGR AGND3 NC NC IPIN IPROGI IPROGR NC NC NC +12V AGND3 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 REMOTE ON/OFF 17 AMX 18 VMX 19 AGND3 20 NC 21 VPSET 22 VMSET 23 IPSET 24 IMSET 25 External Voltage Control Input + Control Common External Voltage Control Input + SWITCH CONFIGURATION (ON REAR PANEL) 12345678 O N for Analoge Voltage Programming 0-5V 12345678 +S + -S NC CS BUS O N 1 2 3 4 5 6 for Analoge Voltage Programming 0-10V Output +VE Output -VE LOAD 61 Fig 4.1b EXTERNAL RESISTANCE PROGRAMMING 0 TO 4.85KOHMS FOR FULL SCALE VOLTAGE & CURRENT NC NC VPROGI VPIN VPROGR AGND3 NC NC IPIN IPROGI IPROGR NC NC NC +12V AGND3 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 REMOTE ON/OFF 17 AMX 18 VMX 19 AGND3 20 NC 21 VPSET 22 VMSET 23 IPSET 24 IMSET 25 +S + -S NC CS BUS Ext. Resistance for voltage control Control Common Ext. Resistance for voltage control SWITCH CONFIGURATION (ON REAR PANEL) 12345678 O N for Resistance Programming 0-5V 1 2 3 4 5 6 12345678 O N for Resistance Programming 0-10V Output +VE Output -VE LOAD 62 Section 7 Customer support B&K Precision offers courteous, professional technical support before and after the sale of their test instruments. The following services are typical of those available from our toll-free telephone number. 1-800-462-9832 l Technical advice on the use of your instrument. l Technical advice on special applications of your instrument. l Technical advice on selecting the test instrument for a given task. l Information on optional accessories for your instrument. l Information on instrument repair and re-calibration services. l Replacement parts ordering. l Availability on service publications. l Information on other B&K Precision instruments. l Information on other B&K Precision Catalog. The name of your nearest B&K Precision Distributor. Call toll free 800-462-9832 Monday through Thursday 8:00 A.M. to 5:00 P.M. Friday 8:00 A.M. to 12:00 P.M. Pacific Standard Time (Pacific Daylight Time Summer) 63 Section8 Warranty information Limited One-Year Warranty B&K Precision warrants to the original purchaser that its products and the component parts thereof, will be free from defects in workmanship and materials for a period of one year from date of purchase from an authorized B&K Precision distributor. B&K Precision will, without charge, repair or replace, at its option, defective product or component parts. Returned product must be accompanied by proof of the purchase date in the form of a sales receipt. To obtain warranty coverage in the U.S.A., this product must be registered by completing the warranty registration form on www.bkprecision.com within fifteen (15) days of purchase. Exclusions: This warranty does not apply in the event of misuse or abuse of the product or as a result of unauthorized alterations or repairs. The warranty is void if the serial number is altered, defaced or removed. B&K Precision shall not be liable for any consequential damages, including without limitation damages resulting from loss of use. Some states do not allow limitations of incidental or consequential damages. So the above limitation or exclusion may not apply to you. This warranty gives you specific rights and you may have other rights, which vary from stateto-state. B&K Precision 22820 Savi Ranch Parkway Yorba Linda, CA 92887 www.bkprecision.com 714-921-9095 64 Section9 Service Information Warranty Service: Please go to our website, www.bkpreicsion.com & click on the service/ repair button to obtain an RMA #. Return the product in the original packaging with proof of purchase to the address below. Clearly state in writing the performance problem and return any leads, probes, connectors and accessories that you are using with the device. Non-Warranty Service: Please go to our website, www.bkpreicsion.com & click on the service/repair button to obtain an RMA #. Return the product in the original packaging to the address below. Clearly state in writing the performance problem and return any leads, probes, connectors and accessories that you are using with the device. Customers not on open account must include payment in the form of a money order or credit card. For the most current repair charges please visit www.bkprecision.com and click on "service/repair". Return all merchandise to B&K Precision Corp. with pre-paid shipping. The flat-rate repair charge for Non-Warranty Service does not include return shipping. Return shipping to locations in North American is included for Warranty Service. For overnight shipments and nonNorth American shipping fees please contact B&K Precision Corp. B&K Precision Corp. 22820 Savi Ranch Parkway Yorba Linda, CA 92887 www.bkprecision.com 714-921-9095 Include with the returned instrument your complete return shipping address, contact name, phone number and description of problem. 65 PN: 481-529-9-001 Printed in India O2004 B&K Precision Corp. 22820 Savi Ranch Parkway Yorba Linda, CA 92887 USA TEL: 714-921-9095 FAX: 714-921-6422 www.bkprecision.com