Digital Triaxial Vibration Sensor with FFT Analysis and Storage ADIS16227 Data Sheet GENERAL DESCRIPTION Frequency domain triaxial vibration sensor Digital acceleration data, 70 g measurement range Digital range settings: 1 g, 5 g, 20 g, 70 g Sample rate: 100.2 kHz, 4 decimation filter settings FFT, 512 point, real valued, all three axes (x, y, z) Windowing options: rectangular, Hanning, flat top Programmable FFT averaging, up to 256 averages Storage, 16 FFT records on all three axes (x, y, z) Programmable alarms, 6 spectral bands 2-level settings for warning and fault definition Adjustable response delay to reduce false alarms Trigger modes: SPI command, timer, external trigger Multirecord capture for selected filter settings Manual capture mode for time-domain data collection Internal self-test with status flags Digital temperature and power supply measurements 2 auxiliary digital I/Os SPI-compatible serial interface Serial number and device ID Single-supply operation: 3.15 V to 3.6 V Operating temperature range: -40C to +125C 15 mm x 15 mm x 15 mm aluminum package, flex connector The ADIS16227 iSensor(R) is a complete vibration sensing system that combines wide bandwidth, triaxial acceleration sensing with advanced time domain and frequency domain signal processing. Time domain signal processing includes a programmable decimation filter and selectable windowing function. Frequency domain processing includes a 512 point, real-valued FFT for each axis, along with FFT averaging, which reduces the noise floor variation for finer resolution. The 16-record FFT storage system offers users the ability to track changes over time and to capture FFTs with multiple decimation filter settings. TE FEATURES B SO LE The 22 kHz sensor resonance and 100.2 kSPS sample rate provide a frequency response that is suitable for machine-health applications. The aluminum core provides excellent mechanical coupling to the MEMS acceleration sensors. An internal clock drives the data sampling and signal processing system during all operations, which eliminates the need for an external clock source. The data capture function has three modes that offer several options to meet the needs of many different applications. APPLICATIONS Vibration analysis Condition monitoring Machine health Instrumentation, diagnostics Safety shutoff sensing The SPI and data buffer structure provide convenient access to wide bandwidth sensor data. The ADIS16227 also offers a digital temperature sensor and digital power supply measurements. The ADIS16227 is available in a 15 mm x 15 mm x 15 mm module with a threaded hole for stud mounting with a 10-32 UNF screw. The dual-row, 1 mm, 14-pin, flexible connector enables simple user interface and installation. The ADIS16227 is footprint and pin-for-pin compatible with the ADIS16223. It has an extended operating temperature range of -40C to +125C. O FUNCTIONAL BLOCK DIAGRAM DIO1 DIO2 RST INPUT/ OUTPUT ADIS16227 VDD ALARMS POWER MANAGEMENT GND CS TRIAXIAL MEMS SENSOR CONTROL REGISTERS CONTROLLER SCLK SPI PORT TEMP SENSOR ADC CAPTURE BUFFER FILTER WINDOW FFT DIN DOUT 09425-001 SUPPLY RECORD STORAGE OUTPUT REGISTERS Figure 1. Rev. B Information furnished by Analog Devices is believed to be accurate and reliable. However, no responsibility is assumed by Analog Devices for its use, nor for any infringements of patents or other rights of third parties that may result from its use. Specifications subject to change without notice. No license is granted by implication or otherwise under any patent or patent rights of Analog Devices. Trademarks and registered trademarks are the property of their respective owners. One Technology Way, P.O. Box 9106, Norwood, MA 02062-9106, U.S.A. Tel: 781.329.4700 www.analog.com Fax: 781.461.3113 (c)2010-2012 Analog Devices, Inc. All rights reserved. ADIS16227 Data Sheet TABLE OF CONTENTS Spectral Alarms............................................................................... 13 Applications ....................................................................................... 1 Alarm Definition ........................................................................ 13 General Description ......................................................................... 1 Alarm Indicator Signals ............................................................. 14 Functional Block Diagram .............................................................. 1 Alarm Flags and Conditions ..................................................... 15 Revision History ............................................................................... 2 Alarm Status ................................................................................ 15 Specifications..................................................................................... 3 Worst-Condition Monitoring ................................................... 15 Timing Specifications .................................................................. 4 Reading Output Data ..................................................................... 16 Absolute Maximum Ratings............................................................ 5 Reading Data from the Data Buffer ......................................... 16 ESD Caution .................................................................................. 5 Accessing FFT Record Data ...................................................... 16 Pin Configuration and Function Descriptions ............................. 6 Data Format ................................................................................ 16 Theory of Operation ........................................................................ 7 Power Supply/Temperature ....................................................... 17 Sensing Element ........................................................................... 7 FFT Event Header ...................................................................... 17 Signal Processing .......................................................................... 7 System Tools .................................................................................... 18 User Interface ................................................................................ 7 Global Commands ..................................................................... 18 LE TE Features .............................................................................................. 1 Status/Error Flags ....................................................................... 18 SPI Write Commands .................................................................. 8 Operation Managment .............................................................. 18 SPI Read Commands ................................................................... 8 Input/Output Functions ............................................................ 19 Data Recording and Signal Processing ........................................ 10 Self-Test ....................................................................................... 19 Recording Modes........................................................................ 10 Flash Memory Management ..................................................... 20 B SO Basic Operation................................................................................. 8 Recording Times......................................................................... 10 Device Identification.................................................................. 20 Power-Down ............................................................................... 11 Applications Information .............................................................. 21 Record Storage Mode ................................................................. 11 Mounting Guidelines ................................................................. 21 Sample Rate Options .................................................................. 11 Getting Started ............................................................................ 21 Windowing Options................................................................... 11 Interface Board ........................................................................... 21 Range ............................................................................................ 12 Outline Dimensions ....................................................................... 22 Offset Correction........................................................................ 12 Ordering Guide .......................................................................... 22 FFT Averaging ............................................................................ 12 O FFT Record Flash Endurance ................................................... 12 REVISION HISTORY 5/12--Rev. A to Rev. B Changes to Table 10 ........................................................................ 10 2/12--Rev. 0 to Rev. A Changes to Dual Memory Structure Section ................................ 7 Change to Table 14 ......................................................................... 11 Changes to Alarm Trigger Settings Section, Enable Alarm Settings Section, Table 27, Table 28, Table 30, and Table 31 ............................................................................................ 14 Change to Alarm Indicator Section ............................................. 19 10/10--Revision 0: Initial Version Rev. B | Page 2 of 24 Data Sheet ADIS16227 SPECIFICATIONS TA = -40C to +125C, VDD = 3.3 V, unless otherwise noted. Table 1. Min TA = 25C TA = 25C, 0 g to 70 g range setting TA = 25C TA = 25C With respect to full scale 70 O Typ 1.192 2.384 5 0.2 2.6 1.5 TE With respect to package TA = 25C -19.1 TJ = 85C, see Figure 18 0.2 -40 -1 10 +19.1 0.8 1 -60 2.4 0.4 10,000 20 RST pulse low or Register GLOB_CMD[7] = 1 REC_CTRL[11:8] = 0x1 (SR0 sample rate selection) Operating voltage range, VDD Record mode, TA = 25C Sleep mode, TA = 25C 2 2.0 VIH = 3.3 V VIL = 0 V ISOURCE = 1.6 mA ISINK = 1.6 mA Max 5 467 3.3 7.75 9.0 13 14.25 26 22 TA = 25C, 100.2 kHz sample rate option TA = 25C, 10 Hz to 1 kHz X/Y-axes, 5% flatness X/Y-axes, 10% flatness Z-axis, 5% flatness Z-axis, 10% flatness -3 dB from 10 Hz magnitude B SO Sensor Resonant Frequency LOGIC INPUTS 1 Input High Voltage, VINH Input Low Voltage, VINL Logic 1 Input Current, IINH Logic 0 Input Current, IINL All Except RST RST Input Capacitance, CIN DIGITAL OUTPUTS1 Output High Voltage, VOH Output Low Voltage, VOL FLASH MEMORY Endurance 2 Data Retention 3 START-UP TIME 4 Initial Startup Reset Recovery 5 Sleep Mode Recovery CONVERSION RATE Clock Accuracy POWER SUPPLY Power Supply Current Test Conditions/Comments LE Parameter ACCELEROMETERS Measurement Range Sensitivity, FFT Sensitivity, Time Domain Sensitivity Error Nonlinearity Cross-Axis Sensitivity Alignment Error Offset Error Offset Temperature Coefficient Output Noise Output Noise Density Bandwidth 3.15 Unit g mg/LSB mg/LSB % % % Degree g mg/C mg rms mg/Hz kHz kHz kHz kHz kHz kHz V V A A mA pF V V Cycles Years 190 54 2.5 100.2 3 3.3 43 230 3.6 52 ms ms ms kSPS % V mA A The digital I/O signals are 5 V tolerant. Endurance is qualified as per JEDEC Standard 22, Method A117, and measured at -40C, +25C, +85C, and +125C. 3 Retention lifetime equivalent at junction temperature (TJ) = 85C as per JEDEC Standard 22, Method A117. Retention lifetime depends on junction temperature. 4 The start-up times presented reflect the time it takes for data collection to begin. 5 The RST pin must be held low for at least 15 ns. 1 2 Rev. B | Page 3 of 24 ADIS16227 Data Sheet TIMING SPECIFICATIONS TA = 25C, VDD = 3.3 V, unless otherwise noted. Table 2. Guaranteed by design, not tested. Unit MHz s ns ns ns ns ns ns ns ns 100 24.4 48.8 12.5 12.5 12.5 5 5 tSF tCS 2 3 4 SCLK 6 B SO tDAV 5 MSB DB14 DB13 tDSU R/W A6 DB12 DB11 A4 A3 tSFS 15 DB10 DB2 16 DB1 LSB tDHD A5 A2 D2 D1 09425-002 1 DIN Max 2.25 tSR CS DOUT Typ LE Timing Diagrams Min 1 0.01 15.4 48.8 LSB Figure 2. SPI Timing and Sequence tSTALL O CS SCLK Figure 3. DIN Bit Sequence Rev. B | Page 4 of 24 09425-003 1 Description SCLK frequency Stall period between data, between 16th and 17th SCLK Chip select to SCLK edge DOUT valid after SCLK edge DIN setup time before SCLK rising edge DIN hold time after SCLK rising edge SCLK rise time SCLK fall time DOUT rise/fall times CS high after SCLK edge TE Parameter fSCLK tSTALL tCS tDAV tDSU tDHD tSR tSF tDF, tDR tSFS Data Sheet ADIS16227 ABSOLUTE MAXIMUM RATINGS Table 4. Package Characteristics Table 3. Rating Package Type 14-Lead Module 2000 g 2000 g -0.3 V to +6.0 V -0.3 V to +5.3 V -0.3 V to +3.6 V -0.3 V to +3.6 V -40C to +125C -65C to +150C JA 31C/W JC 11C/W ESD CAUTION O B SO LE Stresses above those listed under Absolute Maximum Ratings may cause permanent damage to the device. This is a stress rating only; functional operation of the device at these or any other conditions above those indicated in the operational section of this specification is not implied. Exposure to absolute maximum rating conditions for extended periods may affect device reliability. TE Parameter Acceleration Any Axis, Unpowered Any Axis, Powered VDD to GND Digital Input Voltage to GND Digital Output Voltage to GND Analog Inputs to GND Operating Temperature Range Storage Temperature Range Rev. B | Page 5 of 24 Device Weight 6.5 grams ADIS16227 Data Sheet PIN CONFIGURATION AND FUNCTION DESCRIPTIONS aY aZ TOP VIEW LOOK THROUGH PINS ARE NOT VISIBLE FROM THIS VIEW TE aX 14 12 10 8 6 4 2 PIN 2 PIN 13 PIN 1 LE 1. THE ARROWS ASSOCIATED WITH aX, aY, AND aZ DEFINE THE DIRECTION OF VELOCITY CHANGE THAT PRODUCES A POSITIVE OUTPUT IN ACCELERATION OUTPUT REGISTERS. 2. MATING CONNECTOR EXAMPLE: SAMTEC P/N CLM-107-02-LM-D-A. 09425-004 13 11 9 7 5 3 1 Figure 4. Pin Configuration Table 5. Pin Function Descriptions 2 Type 1 S I I/O I/O I S I O2 I I S is supply, O is output, I is input, and I/O is input/output. DOUT is an output when CS is low. When CS is high, DOUT is in a three-state, high impedance mode. O 1 Mnemonic GND NC DIO2 DIO1 RST VDD DIN DOUT SCLK CS B SO Pin No. 1, 4, 9, 10 2, 6 3 5 7 8 11 12 13 14 Rev. B | Page 6 of 24 Description Ground No Connect Digital Input/Output Line 2 Digital Input/Output Line 1 Reset, Active Low Power Supply, 3.3 V SPI, Data Input SPI, Data Output SPI, Serial Clock SPI, Chip Select Data Sheet ADIS16227 THEORY OF OPERATION OUTPUT REGISTERS TEMP SENSOR ADC CONTROLLER MOVABLE FRAME FIXED PLATES B SO UNIT SENSING CELL UNIT FORCING CELL MOVING PLATE ANCHOR 09425-005 ACCELERATION PLATE CAPACITORS Figure 5. MEMS Sensor Diagram SIGNAL PROCESSING O Figure 6. Simplified Sensor Signal Processing Diagram USER INTERFACE TE SPI Interface The user registers manage user access to both sensor data and configuration inputs. Each 16-bit register has its own unique bit assignment and two addresses: one for its upper byte and one for its lower byte. Table 8 provides a memory map for each register, along with its function and lower byte address. The data collection and configuration command uses the SPI, which consists of four wires. The chip select (CS) signal activates the SPI interface, and the serial clock (SCLK) synchronizes the serial data lines. Input commands clock into the DIN pin, one bit at a time, on the SCLK rising edge. Output data clocks out of the DOUT pin on the SCLK falling edge. When the SPI is used as a slave device, the DOUT contents reflect the information requested using a DIN command. Figure 6 offers a simplified block diagram for the ADIS16227. The signal processing stage includes time domain data capture, digital decimation/filtering, windowing, FFT analysis, FFT averaging, and record storage. See Figure 13 for more details on the signal processing operation. Dual Memory Structure The user registers provide addressing for all input/output operations in the SPI interface. The control registers use a dual memory structure. The controller uses SRAM registers for normal operation, including user-configuration commands. The flash memory provides nonvolatile storage for control registers that have flash backup (see Table 8). Storing configuration data in the flash memory requires a manual flash update command (GLOB_CMD[6] = 1, DIN = 0xBE40). When the device powers on or resets, the flash memory contents load into the SRAM, and the device starts producing data according to the configuration in the control registers. MANUAL FLASH BACKUP NONVOLATILE FLASH MEMORY (NO SPI ACCESS) VOLATILE SRAM SPI ACCESS START-UP RESET Figure 7. SRAM and Flash Memory Diagram Rev. B | Page 7 of 24 09425-007 ANCHOR CLOCK LE Digital vibration sensing in the ADIS16227 starts with a wide bandwidth MEMS accelerometer core on each axis, which provides a linear motion-to-electrical transducer function. Figure 5 provides a basic physical diagram of the sensing element and its response to linear acceleration. It uses a fixed frame and a moving frame to form a differential capacitance network that responds to linear acceleration. Tiny springs tether the moving frame to the fixed frame and govern the relationship between acceleration and physical displacement. A modulation signal on the moving plate feeds through each capacitive path into the fixed frame plates and into a demodulation circuit, which produces the electrical signal that is proportional to the acceleration acting on the device. 09425-006 SENSING ELEMENT CONTROL REGISTERS SPI SIGNALS CAPTURE BUFFER TRIAXIAL MEMS SENSOR SPI PORT The ADIS16227 is a triaxial, wide bandwidth, vibration-sensing system. It combines a triaxial MEMS accelerometer with a sampling and advanced signal processing system. The SPIcompatible port and user register structure provide convenient access to frequency domain vibration data and many user controls. ADIS16227 Data Sheet BASIC OPERATION VDD 15 14 13 12 SCLK 13 SCLK MOSI 11 DIN MISO 12 DOUT IRQ1 5 DIO1 IRQ2 3 DIO2 CS 6 5 4 3 2 1 LOWER BYTE 10 0 CS LE 9 09425-008 4 7 TE SPI SLAVE 1 8 User control registers govern many internal operations. The DIN bit sequence in Figure 12 provides the ability to write to these registers, one byte at a time. Some configuration changes and functions require only one write cycle. For example, set GLOB_CMD[11] = 1 (DIN = 0xBF08) to start a manual capture sequence. The manual capture starts immediately after the last bit clocks into DIN (16th SCLK rising edge). Other configurations may require writing to both bytes. ADIS16227 14 9 SPI WRITE COMMANDS 8 SS 10 Figure 9. Generic Register Bit Definitions +3.3V SYSTEM PROCESSOR SPI MASTER 11 UPPER BYTE 09425-009 Table 8 provides a list of user registers with their lower byte addresses. Each register consists of two bytes that each have their own, unique 7-bit addresses. Figure 9 relates each register's bits to their upper and lower addresses. The ADIS16227 uses a SPI for communication, which enables a simple connection with a compatible, embedded processor platform, as shown in Figure 8. The factory default configuration for DIO1 provides a busy indicator signal that transitions low when an event completes and data is available for user access. Use the DIO_CTRL register (see Table 59) to reconfigure DIO1 and DIO2, if necessary. Figure 8. Electrical Hook-Up Diagram DIN Function Slave select Interrupt request inputs (optional) Master output, slave input Master input, slave output Serial clock Figure 10. SPI Sequence for Manual Capture Start (DIN = 0xBF08) SPI READ COMMANDS A single register read requires two 16-bit SPI cycles that also use the bit assignments in Figure 12. The first sequence sets R/W = 0 and communicates the target address (Bits[A6:A0]). Bits[D7:D0] are don't care bits for a read DIN sequence. DOUT clocks out the requested register contents during the second sequence. The second sequence can also use DIN to set up the next read. Figure 11 provides a signal diagram for all four SPI signals while reading the PROD_ID register (see Table 63) pattern. In this diagram, DIN = 0x5600 and DOUT reflect the decimal equivalent of 16,227. B SO Pin Name SS IRQ1, IRQ2 MOSI MISO SCLK 09425-010 SCLK Table 6. Generic Master Processor Pin Names and Functions The ADIS16227 SPI interface supports full duplex serial communication (simultaneous transmit and receive) and uses the bit sequence shown in Figure 12. Table 7 provides a list of the most common settings that require attention to initialize a processor serial port for the ADIS16227 SPI interface. Table 7. Generic Master Processor SPI Settings CS Description ADIS16227 operates as a slave. Bit rate setting. Clock polarity/phase (CPOL = 1, CPHA = 1). Bit sequence. Shift register/data length. SCLK O MSB-First 16-Bit DIN DOUT DOUT = 0011 1111 0110 0011 = 0x3F63 = 16,227 = PROD_ID Figure 11. Example SPI Read, PROD_ID, Second Sequence CS SCLK DOUT R/W DB15 A6 A5 A4 A3 A2 A1 A0 DB14 DB13 DB12 DB11 DB10 DB9 DB8 D7 D6 D5 D4 D3 D2 D1 D0 DB7 DB6 DB5 DB4 DB3 DB2 DB1 DB0 NOTES 1. DOUT BITS ARE BASED ON THE PREVIOUS 16-BIT SEQUENCE (R/W = 0). Figure 12. Example SPI Read Sequence Rev. B | Page 8 of 24 R/W DB15 A6 A5 DB14 DB13 09425-012 DIN 09425-011 Processor Setting Master SCLK Rate 2.25 MHz SPI Mode 3 Data Sheet ADIS16227 Table 8. User Register Memory Map Address 0x00 0x02 0x04 0x06 0x08 0x0A 0x0C 0x0E 0x10 0x12 0x14 0x16 0x18 0x1A 0x1C 0x1E 0x20 0x22 0x24 0x26 0x28 0x2A 0x2C 0x2E 0x30 0x32 0x34 0x36 0x38 0x3A 0x3C 0x3E 0x40 0x42 0x44 0x46 0x48 0x4A 0x4C 0x4E 0x50 to 0x51 0x52 0x54 0x56 0x58 0x70 0x72 0x74 0x76 Default N/A 0x0000 0x0000 0x0000 N/A 0x8000 0x8000 0x0008 0x0000 0x0000 0x8000 0x8000 0x8000 0x0000 0x1130 0x0000 0x0000 0x0000 0x0000 0x0000 0x0000 0x0000 0x0000 0x0000 0x0000 0x0000 0x0080 0x000F 0x0000 N/A 0x0000 N/A 0x0000 0x0000 0x0000 0x0000 0x0000 0x0000 0x0000 0x0000 N/A N/A N/A 0x3F63 N/A 0x0000 0x0000 0x0000 N/A O Function Status, flash memory write count X-axis accelerometer offset correction Y-axis accelerometer offset correction Z-axis accelerometer offset correction Record flash write/erase counter Output, power supply during capture Output, temperature during capture Control, number of FFT records to average Control, buffer address pointer Control, record address pointer Output, buffer for x-axis acceleration data Output, buffer for y-axis acceleration data Output, buffer for z-axis acceleration data Control, record counter Control, record control register Control, record period (automatic mode) Alarm, spectral band lower frequency limit Alarm, spectral band upper frequency limit Alarm, x-axis, Alarm 1 level Alarm, y-axis, Alarm 1 level Alarm, z-axis, Alarm 1 level Alarm, x-axis, Alarm 2 level Alarm, y-axis, Alarm 2 level Alarm, z-axis, Alarm 2 level Alarm, spectral alarm band pointer Alarm, system alarm level Alarm, configuration Control, functional I/O configuration Control, general-purpose I/O Reserved Status, system error flags Control, global command register Alarm, x-axis, status for spectral alarm bands Alarm, y-axis, status for spectral alarm bands Alarm, z-axis, status for spectral alarm bands Alarm, x-axis, peak value (most severe alarm) Alarm, y-axis, peak value (most severe alarm) Alarm, z-axis, peak value (most severe alarm) Record time stamp, lower word Record time stamp, upper word Reserved Lot identification code Lot identification code Product identifier; convert to decimal = 16,227 Serial number Alarm, x-axis, frequency of most severe alarm Alarm, y-axis, frequency of most severe alarm Alarm, z-axis, frequency of most severe alarm Record settings TE Flash Backup Yes Yes Yes Yes No Yes Yes Yes Yes Yes No No No No Yes Yes N/A N/A N/A N/A N/A N/A N/A N/A Yes Yes Yes Yes Yes N/A No No N/A N/A N/A N/A N/A N/A N/A N/A N/A Yes Yes Yes Yes N/A N/A N/A N/A LE Access Read only Read only Read only Read only N/A Read only Read only Read/write Read/write Read/write Read only Read only Read only Read/write Read/write Read/write Read/write Read/write Read/write Read/write Read/write Read/write Read/write Read/write Read/write Read/write Read/write Read/write Read/write N/A Read only Write only Read only Read only Read only Read only Read only Read only Read only Read only N/A Read only Read only Read only Read only Read only Read only Read only Read only B SO Register Name FLASH_CNT X_NULL Y_NULL Z_NULL REC_FLSH_CNT SUPPLY_OUT TEMP_OUT FFT_AVG BUF_PNTR REC_PNTR X_BUF Y_BUF Z_BUF REC_CNTR REC_CTRL REC_PRD ALM_F_LOW ALM_F_HIGH ALM_X_MAG1 ALM_Y_MAG1 ALM_Z_MAG1 ALM_X_MAG2 ALM_Y_MAG2 ALM_Z_MAG2 ALM_PNTR ALM_S_MAG ALM_CTRL DIO_CTRL GPIO_CTRL Reserved DIAG_STAT GLOB_CMD ALM_X_STAT ALM_Y_STAT ALM_Z_STAT ALM_X_PEAK ALM_Y_PEAK ALM_Z_PEAK TIME_STAMP_L TIME_STAMP_H Reserved LOT_ID1 LOT_ID2 PROD_ID SERIAL_NUM ALM_X_FREQ ALM_Y_FREQ ALM_Z_FREQ REC_INFO Rev. B | Page 9 of 24 Reference Table 61 Table 18 Table 18 Table 18 Table 20 Table 48 Table 50 Table 19 Table 43 Table 44 Table 45 Table 45 Table 45 Table 13 Table 10 Table 11 Table 24 Table 25 Table 26 Table 27 Table 28 Table 29 Table 30 Table 31 Table 23 Table 32 Table 22 Table 59 Table 60 N/A Table 58 Table 57 Table 33 Table 34 Table 35 Table 36 Table 37 Table 38 Table 54 Table 55 N/A Table 62 Table 62 Table 63 Table 64 Table 39 Table 40 Table 41 Table 53 ADIS16227 Data Sheet DATA RECORDING AND SIGNAL PROCESSING The ADIS16227 provides a number of registers for configuring its data collection and signal processing operation (see Table 9). Figure 13 provides a signal flow diagram, which describes many of these settings. Table 9. Sampling/Signal Processing Register Summary Address 0x02 0x04 0x06 0x08 0x0E 0x1A 0x1C 0x1E 0x3E Description X-axis offset correction Y-axis offset correction Z-axis offset correction Record, flash write cycle counter Record, FFT averages Record, counter Record, data processing Record, automatic mode period Trigger, record commands Table 11. REC_PRD Register Bit Descriptions Bits [15:10] [9:8] Table 10. REC_CTRL Bit Descriptions [3:2] [1:0] Description (Default = 0x1130) Not used Window setting: 00 = rectangular, 01 = Hanning, 10 = flat top, 11 = N/A SR3, fs / 512 (1 = enabled for analysis) SR2, fs / 64 (1 = enabled for analysis) SR1, fs / 8 (1 = enabled for analysis) SR0, fs (1 = enabled for analysis) Power-down between each recording (1 = enabled) Not used Signal range: 00 = 0 g to 1 g, 01 = 0 g to 5 g, 10 = 0 g to 20 g, 11 = 0 g to 70 g Storage method: 00 = none, 01 = alarm trigger, 10 = all, 11 = N/A Recording mode: 00 = manual, 01 = automatic, 10 = manual time, 11 = N/A O [11] [10] [9] [8] [7] [6] [5:4] RECORDING TIMES The automatic recording period (REC_PRD) must be greater than the total recording time. Use the following equations to calculate the recording time: Manual time mode TR = TS + TPT + TST + TAST FFT modes B SO Bits [15:14] [13:12] [7:0] LE The record control register is REC_CTRL (see Table 10), which provides external controls for sample rates, dynamic range, record storage, recording mode, and power management. Description (Default = 0x0000) Not used Scale for data bits 00 = 1 second/LSB 01 = 1 minute/LSB 10 = 1 hour/LSB Data bits, binary format, range = 0 to 255 TE Register X_NULL Y_NULL Z_NULL REC_FLSH_CNT FFT_AVG REC_CNTR REC_CTRL REC_PRD GLOB_CMD For example, set DIO_CTRL[7:0] = 0x2F (DIN = 0xB62F) to configure DIO2 as a positive external trigger input and maintain the DIO1 factory default configuration as a positive busy indicator. In manual mode, the start command triggers a recording for an averaged FFT and stops after the recording is complete. In automatic mode, the start command executes a recording, and a timer continues to trigger recordings based on the record period setting in REC_PRD (see Table 11). RECORDING MODES REC_CTRL[1:0] provides three modes for triggering: (1) manual, (2) automatic, and (3) manual time domain. The manual and automatic modes produce FFT events, which include data collection, filtering, windowing, FFT analysis, and record storage (if selected). The manual time domain mode produces time-domain data in the buffer. All three modes require an external trigger, using either the SPI interface or one of the auxiliary digital I/O lines, DIO1 or DIO2. For the SPI external trigger option, set GLOB_CMD[11] = 1 (DIN = 0x3F08). For the digital I/O option, use the DIO_CTRL register (see Table 59) to configure either DIO1 or DIO2 as an external trigger input. TR = N F x (TS + TPT + TFFT ) + TST + TAST The storage time (TST) applies only when a storage method is selected in REC_CTRL[3:2]. See Table 10 for more details on the record storage setting. The alarm scan time (TAST) applies only when the alarms are enabled in ALM_CTRL[4:0]. See Table 22 for more details on enabling the alarms. Table 12. Available Records Function Sample Time, TS Processing Time, TPT FFT Time, TFFT Number of FFT Averages, NF Storage Time, TST Alarm Scan Time, TAST Rev. B | Page 10 of 24 Time (ms) See Table 15 10.4 26.6 See Table 19 120.0 2.21 Data Sheet ADIS16227 Table 14. Sample Rate Settings and Filter Performance Set GLOB_CMD[1] = 1 (DIN = 0xBE02) to power down the ADIS16227. To reduce power consumption, set REC_CTRL[7] = 1 to automatically power down after a record has completed. Toggle the CS line from high to low to wake the device up and place it in an idle state, where it waits for the next command. When configured as an external trigger option, toggling DIO1 or DIO2 can wake the device up as well. Using DIO1 or DIO2 for this purpose avoids the potential for multiple devices contending for DOUT when waking up with the CS line approach. After completing the record cycle, the device remains awake. Use GLOB_CMD[1] to put it back to sleep after reading the record data. RECORD STORAGE MODE Sample Rate (SPS) 100,189 12,524 1566 196 Bin Width (Hz) 196 25 3.1 0.38 Bandwidth (Hz) 26,000 6,262 783 98 Noise (mg) 467 260 100 38 Table 15 provides the data sampling time (TS) for each sample rate setting. This represents the time it takes to record data for all three axes of vibration data. Table 15. Sample Times, TS Sample Rate Setting SR0, REC_CTRL[8] = 1 SR1, REC_CTRL[9] = 1 SR2, REC_CTRL[10] = 1 SR3, REC_CTRL[11] = 1 Sample Time (ms), TS 5.27 42.15 337.17 2697.39 If more than one sample rate setting is active in REC_CTRL[11:8], the sample rate setting automatically updates after each FFT event and waits for the next trigger input. The order of priority starts with the highest sample rate enabled and works toward the lowest after each REC_CTRL[11:8] write cycle. When used in conjunction with automatic trigger mode and record storage, FFT analysis for each sample rate option requires no further user inputs, except for collecting the data. Depending on the number of FFT averages, the time period between each sample rate selection may be quite large. Note that selecting multiple sample rates reduces the number of records available for each sample rate setting, as shown in Table 16. B SO LE After the ADIS16227 finishes processing FFT data, it stores the data into the FFT buffer, where it is available for external access using the SPI and x_BUF registers. REC_CTRL[3:2] provides programmable conditions for writing buffer data into the FFT records, which are in nonvolatile flash memory locations. Set REC_CTRL[3:2] = 01 to store FFT buffer data into the flash memory records only when an alarm condition is met. Set REC_CTRL[3:2] = 10 to store every set of FFT data into the flash memory locations. The flash memory record provides space for a total of 16 records. Each record stored in flash memory contains a header and frequency domain (FFT) data from all three axes (x, y, and z). When all 16 records are full, new records do not load into the flash memory. The REC_CNTR register (see Table 13) provides a running count for the number of records that are stored. Set GLOB_CMD[8] = 1 (DIN = 0xBF01) to clear all of the records in flash memory. Setting SR0 SR1 SR2 SR3 TE POWER-DOWN Table 13. REC_CNTR Bit Descriptions Bits [15:5] [4:0] Description (Default = 0x0000) Not used Total number of records taken, range = 0 to 16, binary Table 16. Available Records Number of Sample Rates Selected 1 2 3 4 Available Records 16 8 5 4 WINDOWING OPTIONS The analog-to-digital converter (ADC) samples each accelerometer sensor at a rate of 100.2 kSPS (fs). REC_CTRL[11:8] provide four different sample rate options for FFT analysis: SR0 (fs), SR1(fs / 8), SR2 (fs / 64), and SR3 (fs / 512). The reduced rates come from a decimation filter, which reduces the bandwidth and bin widths. See Figure 13 for the filter location in the signal processing diagram and Table 14 for the performance trade-offs associated with each sample rate setting. REC_CTRL[13:12] provide three options for pre-FFT windowing of time data. For example, set REC_CTRL[13:12] = 01 to use the Hanning window, which offers the best amplitude resolution of the peaks between frequency bins and minimal broadening of peak amplitudes. The rectangular and flat top windows are also available because they are common windowing options for vibration monitoring. The flat top window provides accurate amplitude resolution with a trade-off of broadening the peak amplitudes. O SAMPLE RATE OPTIONS Rev. B | Page 11 of 24 ADIS16227 Data Sheet RANGE FFT AVERAGING REC_CTRL[5:4] provide four range options for scaling acceleration data prior to the FFT analysis stage. For example, set REC_CTRL[5:4] = 10 to set the peak acceleration (AMAX) to 5 g. See Table 17 for the resolution associated with each setting and Figure 13 for the location of this operation in the signal flow diagram. The FFT averaging function records a programmable number of FFTs and combines them into a single, averaged FFT record. This function is useful in reducing the variation of the FFT noise floor, which enables detection of lower vibration levels. To enable this function, write the number of averages to FFT_AVG. Setting FFT_AVG = 0x0000 has the same effect as setting FFT_AVG = 0x0001: no averaging. Setting FFT_AVG 0x0100 results in a setting of 256. Therefore, set FFT_AVG[15:8] = 0x01 (DIN = 0x8F01) to establish the maximum average setting of 256. Another example configuration is to set FFT_AVG = 0x00F0 (DIN = 0x8F00, DIN = 0x8EF0) to establish an average setting of 240. Table 17. Range Setting and LSB Weights Time Mode (mg/LSB) 0.0305 0.1526 0.6104 2.3842 FFT Mode (mg/LSB) 0.0153 0.0763 0.3052 1.1921 TE Table 19. FFT_AVG Register Bit Descriptions Bits [15:9] [8:0] OFFSET CORRECTION The x_NULL registers (see Table 18) contain the offset correction factors generated when using the internal, autonull command. They represent the KO factor in Figure 13 and follow the digital format in Table 18. Set GLOB_CMD[0] =1 (DIN = 0xBE01) and wait for 681 ms to execute this function. LE FFT RECORD FLASH ENDURANCE The REC_FLSH_CNT register (see Table 20) increments each time that all 16 records have FFT data. Table 18. X_NULL, Y_NULL, and Z_NULL Bit Descriptions Table 20. REC_FLSH_CNT Bit Descriptions Description (Default = 0x0000) Offset correction factor, twos complement, 2.3842 mg/LSB Bits [15:0] B SO Bits [15:0] Description (Default = 0x0008) Not used Number of FFT averages for a single record, NF in Figure 13, range = 1 to 256, binary RANGE-SCALE SETTING Ks= AMAX / 215 AMAX = PEAK FROM REC_CTRL[5:4] OFFSET CORRECTION KO = X_NULL, Y_NULL, Z_NULL SAMPLE RATE SETTING REC_CTRL[11:8] 100kSPS 1 NA Ks WINDOW SETTING REC_CTRL[13:12] FFT RECORDS--NONVOLATILE FLASH MEMORY FFT RECORD 0 xK K=1 /N A + WINDOW FFT RECORD 1 NF = # OF AVERAGES NF = FFT_AVG[8:0] Na O TRIAXIS MEMS ACCEL Ko Description Flash write cycle count, record data only, binary FFT FFT AVERAGE (NF) Figure 13. Signal Flow Diagram, REC_CTRL[1:0] = 00 or 01, FFT Analysis Modes Rev. B | Page 12 of 24 FFT RECORD m FFT RECORD 15 m = REC_CNTR REC_CTRL[3:2] FFT BUFFER BUFFER REGISTER AND SPI 09425-016 Range Setting (g) (REC_CTRL[5:4]) 0 to 1 0 to 5 0 to 20 0 to 70 Data Sheet ADIS16227 SPECTRAL ALARMS The ALM_CTRL register (see Table 22) provides control bits that enable each axis' spectral alarms, configures the system alarm, sets the record delay for the spectral alarms, and configures the clearing function for the DIAG_STAT error flags. Table 22. ALM_CTRL Bit Descriptions Description (Default = 0x0080) Not used Response delay, range: 0 to 15; represents the number of spectral records for each spectral alarm before a spectral alarm flag is set high Latch DIAG_STAT error flags, which requires a clear status command (GLOB_CMD[4]) to reset the flags to 0 (1 = enabled, 0 = disabled) Enable DIO1 as an Alarm 1 output indicator and enable DIO2 as an Alarm2 output indicator (1 = enabled) System alarm comparison polarity 1 = trigger when less than ALM_MAGS[11:0] 0 = trigger when greater than ALM_MAGS[11:0] System alarm, 1 = temperature 0 = power supply Alarm S enable (ALM_S_MAG), 1 = enabled, 0 = disabled Alarm Z enable (ALM_Z_MAG), 1 = enabled, 0 = disabled Alarm Y enable (ALM_Y_MAG), 1 = enabled, 0 = disabled Alarm X enable (ALM_X_MAG), 1 = enabled, 0 = disabled O Bits [15:12] [11:8] [7] [6] [5] [4] [3] [2] [1] [0] ALM_F_LOW ALM_x_MAG2 ALM_F_HIGH ALM_x_MAG1 1 2 3 4 5 FREQUENCY 6 09425-020 LE Description Alarm frequency, lower limit Alarm frequency, upper limit X-Alarm Trigger Level 1 (warning) Y-Alarm Trigger Level 1 (warning) Z-Alarm Trigger Level 1 (warning) X-Alarm Trigger Level 2 (fault) Y-Alarm Trigger Level 2 (fault) Z-Alarm Trigger Level 2 (fault) Alarm pointer System alarm trigger level Alarm configuration Alarm status X-alarm status Y-alarm status Z-alarm status X-alarm peak Y-alarm peak Z-alarm peak X-axis alarm frequency of peak alarm Y-axis alarm frequency of peak alarm Z-axis alarm frequency of peak alarm B SO Address 0x20 0x22 0x24 0x26 0x28 0x2A 0x2C 0x2E 0x30 0x32 0x34 0x3C 0x40 0x42 0x44 0x46 0x48 0x4A 0x70 0x72 0x74 The alarm function provides six programmable spectral bands, as shown in Figure 14. Each spectral alarm band has lower and upper frequency definitions for all four sample rate options. It also has two independent trigger level settings, which are useful for systems that value warning and fault condition indicators. TE Table 21. Alarm Function Register Summary Register ALM_F_LOW ALM_F_HIGH ALM_X_MAG1 ALM_Y_MAG1 ALM_Z_MAG1 ALM_X_MAG2 ALM_Y_MAG2 ALM_Z_MAG2 ALM_PNTR ALM_S_MAG ALM_CTRL DIAG_STAT ALM_X_STAT ALM_Y_STAT ALM_Z_STAT ALM_X_PEAK ALM_Y_PEAK ALM_Z_PEAK ALM_X_FREQ ALM_Y_FREQ ALM_Z_FREQ ALARM DEFINITION MAGNITUDE The alarm function offers six spectral bands for alarm detection. Each spectral band has high and low frequency definitions, along with two different trigger thresholds (Alarm 1 and Alarm 2) for each accelerometer axis. Table 21 provides a summary of each register used to configure the alarm function. Figure 14. Spectral Band Alarm Setting Example, ALM_PNTR = 0x03 Select the spectral band for configuration by writing its number (1 to 6) to ALM_PNTR[2:0] (see Table 23). Then, select the sample rate setting using ALM_PNTR[9:8]. This number represents a binary number, which corresponds to the x in the SRx sample rates settings associated with REC_CTRL[11:8] (see Table 10). For example set ALM_PNTR[7:0] = 0x05 (DIN = 0xB005) to select Alarm Spectral Band 5 and set ALM_PNTR[15:8] = 0x02 (DIN = 0xB102) to select the SR2 sample rate option from Table 14, 1,566 SPS. Table 23. ALM_PNTR Bit Assignments Bits [15:10] [9:8] [7:3] [2:0] Rev. B | Page 13 of 24 Description (Default = 0x0000) Not used Sample rate setting, range: 0 to 3 Not used Spectral band number, range: 1 to 6 ADIS16227 Data Sheet After the spectral band and sample rate settings are set, program the lower and upper frequency boundaries by writing their bin numbers to the ALM_F_LOW (see Table 24) and ALM_F_HIGH (see Table 25) registers. Use the bin width definitions in Table 14 to convert a frequency into a bin number for this definition. Calculate the bin number by dividing the frequency by the bin width associated with the sample rate setting. For example, 3400 Hz, divided by 196 Hz/bin (SR0 setting), rounded to the nearest integer, is equal to 17, or 0x12. Therefore, set ALM_F_LOW[7:0] = 0x11 (DIN = 0xA011) to establish 3400 Hz as the lower frequency for the SR0 sample rate setting. Table 24. ALM_F_LOW Bit Assignments Bits [15:8] [7:0] Bits [15:0] Table 30. ALM_Y_MAG2 Bit Assignments Bits [15:0] Description (Default = 0x0000) Y-axis Alarm Trigger Level 2, 16-bit unsigned; see REC_CTRL[5:4] and Table 17 for the scale factor Description (Default = 0x0000) Z-axis Alarm Trigger Level 1, 16-bit unsigned; see REC_CTRL[5:4] and Table 17 for the scale factor LE Bits [15:0] Description (Default = 0x0000) System alarm trigger level, data format matches target from ALM_CTRL[4] Enable Alarm Settings Before configuring the spectral alarm registers, clear their current contents by setting GLOB_CMD[9] = 1 (DIN = 0xBF02). After completing the spectral alarm band definitions, enable the settings by setting GLOB_CMD[12] = 1 (DIN = 0xBF10). The device ignores the save command if any of these locations have already been written to. B SO O ALM_X_MAG2 > ALM_X_MAG1 ALM_Y_MAG2 > ALM_Y_MAG1 ALM_Z_MAG2 > ALM_Z_MAG1 ALARM INDICATOR SIGNALS DIO_CTRL[5:2] and ALM_CTRL[6] provide controls for establishing DIO1 and DIO2 as dedicated alarm output indicator signals. Use DIO_CTRL[5:2] to select Alarm function for DIO1 and/or DIO2; then set ALM_CTRL[6] = 1 to enable DIO1 to serve as an Alarm 1 indicator and DIO2 as an Alarm 2 indicator. This setting establishes DIO1 to indicate Alarm 1 (warning) conditions and DIO2 to indicate Alarm 2 (critical) conditions. Table 26. ALM_X_MAG1 Bit Assignments Description (Default = 0x0000) X-axis Alarm Trigger Level 1, 16-bit unsigned; see REC_CTRL[5:4] and Table 17 for the scale factor Table 27. ALM_Y_MAG1 Bit Assignments Bits [15:0] Description (Default = 0x0000) X-axis Alarm Trigger Level 2, 16-bit unsigned; see REC_CTRL[5:4] and Table 17 for the scale factor Table 32. ALM_S_MAG Bit Assignments The ALM_x_MAG1 and ALM_x_MAG2 registers provide two independent trigger settings for all three axes of acceleration data. They use the data format established by the range setting in REC_CTRL[5:4] and recording mode in REC_CTRL[1:0]. For example, when using the 0 g to 1 g mode for FFT analysis, 3277 LSB is equivalent to 500.07 mg. To set the critical alarm to 500.07 mg when using the 0 g to 1 g range option in REC_CTRL2 for FFT records, set ALM_X_MAG2 = 0x0CCD (DIN = 0xAD0C, 0xACCD). See Table 10 and Table 17 for more information on formatting each trigger level. Note that trigger settings associated with Alarm 2 should be greater than the trigger settings for Alarm 1. In other words, the alarm magnitude settings should meet the following criteria: Bits [15:0] Description (Default = 0x0000) Z-axis Alarm Trigger Level 1, 16-bit unsigned; see REC_CTRL[5:4] and Table 17 for the scale factor Table 29. ALM_X_MAG2 Bit Assignments Bits [15:0] Description (Default = 0x0000) Not used Upper frequency, bin number, range = 0 to 255 Alarm Trigger Settings Bits [15:0] Table 31. ALM_Z_MAG2 Bit Assignments Description (Default = 0x0000) Not used Lower frequency, bin number, range = 0 to 255 Table 25. ALM_F_HIGH Bit Assignments Bits [15:8] [7:0] Table 28. ALM_Z_MAG1 Bit Assignments TE Alarm Band Frequency Definitions Description (Default = 0x0000) Y-axis Alarm Trigger Level 1, 16-bit unsigned; see REC_CTRL[5:4] and Table 17 for the scale factor Rev. B | Page 14 of 24 Data Sheet ADIS16227 Table 35. ALM_Z_STAT Bit Assignments The FFT header (see Table 52) contains both generic alarm flags (DIAG_STAT[13:8] (see Table 58) and spectral band-specific alarm flags (ALM_x_STAT, see Table 33, Table 34 and Table 35). The FFT header also contains magnitude (ALM_x_PEAK, see Table 36, Table 37 and Table 38) and frequency information (ALM_x_FREQ, see Table 39, Table 40, and Table 41) associated with the highest magnitude of vibration content in the record. ALARM STATUS The ALM_x_STAT registers, in Table 33, Table 34, and Table 35, provide alarm bits for each spectral band on the current sample rate option. Table 33. ALM_X_STAT Bit Assignments Table 34. ALM_Y_STAT Bit Assignments Description (Default = 0x0000) Alarm 2 on Band 6, 1 = alarm set, 0 = no alarm Alarm 1 on Band 6, 1 = alarm set, 0 = no alarm Alarm 2 on Band 5, 1 = alarm set, 0 = no alarm Alarm 1 on Band 5, 1 = alarm set, 0 = no alarm Alarm 2 on Band 4, 1 = alarm set, 0 = no alarm Alarm 1 on Band 4, 1 = alarm set, 0 = no alarm Alarm 2 on Band 3, 1 = alarm set, 0 = no alarm Alarm 1 on Band 3, 1 = alarm set, 0 = no alarm Alarm 2 on Band 2, 1 = alarm set, 0 = no alarm Alarm 1 on Band 2, 1 = alarm set, 0 = no alarm Alarm 2 on Band 1, 1 = alarm set, 0 = no alarm Alarm 1 on Band 1, 1 = alarm set, 0 = no alarm Not used Most critical alarm condition, spectral band, range: 1 to 6 O Bits [15] [14] [13] [12] [11] [10] [9] [8] [7] [6] [5] [4] [3] [2:0] Description (Default = 0x0000) Alarm 2 on Band 6, 1 = alarm set, 0 = no alarm Alarm 1 on Band 6, 1 = alarm set, 0 = no alarm Alarm 2 on Band 5, 1 = alarm set, 0 = no alarm Alarm 1 on Band 5, 1 = alarm set, 0 = no alarm Alarm 2 on Band 4, 1 = alarm set, 0 = no alarm Alarm 1 on Band 4, 1 = alarm set, 0 = no alarm Alarm 2 on Band 3, 1 = alarm set, 0 = no alarm Alarm 1 on Band 3, 1 = alarm set, 0 = no alarm Alarm 2 on Band 2, 1 = alarm set, 0 = no alarm Alarm 1 on Band 2, 1 = alarm set, 0 = no alarm Alarm 2 on Band 1, 1 = alarm set, 0 = no alarm Alarm 1 on Band 1, 1 = alarm set, 0 = no alarm Not used Most critical alarm condition, spectral band, range: 1 to 6 WORST-CONDITION MONITORING The ALM_x_PEAK registers (see Table 36, Table 37, and Table 38) contain the peak magnitude for the worst-case alarm condition in each axis. The ALM_x_FREQ registers (see Table 39, Table 40, and Table 41) contain the frequency bin number for the worst-case alarm condition. LE Description (Default = 0x0000) Alarm 2 on Band 6, 1 = alarm set, 0 = no alarm Alarm 1 on Band 6, 1 = alarm set, 0 = no alarm Alarm 2 on Band 5, 1 = alarm set, 0 = no alarm Alarm 1 on Band 5, 1 = alarm set, 0 = no alarm Alarm 2 on Band 4, 1 = alarm set, 0 = no alarm Alarm 1 on Band 4, 1 = alarm set, 0 = no alarm Alarm 2 on Band 3, 1 = alarm set, 0 = no alarm Alarm 1 on Band 3, 1 = alarm set, 0 = no alarm Alarm 2 on Band 2, 1 = alarm set, 0 = no alarm Alarm 1 on Band 2, 1 = alarm set, 0 = no alarm Alarm 2 on Band 1, 1 = alarm set, 0 = no alarm Alarm 1 on Band 1, 1 = alarm set, 0 = no alarm Not used Most critical alarm condition, spectral band, range: 1 to 6 B SO Bits [15] [14] [13] [12] [11] [10] [9] [8] [7] [6] [5] [4] [3] [2:0] Bits [15] [14] [13] [12] [11] [10] [9] [8] [7] [6] [5] [4] [3] [2:0] TE ALARM FLAGS AND CONDITIONS Table 36. ALM_X_PEAK Bit Assignments Bits [15:0] Description (Default = 0x0000) Alarm peak, x-axis, accelerometer data format Table 37. ALM_Y_PEAK Bit Assignments Bits [15:0] Description (Default = 0x0000) Alarm peak, y-axis, accelerometer data format Table 38. ALM_Z_PEAK Bit Assignments Bits [15:0] Description (Default = 0x0000) Alarm peak, z-axis, accelerometer data format Table 39. ALM_X_FREQ Bit Assignments Bits [15:8] [7:0] Description (Default = 0x0000) Not used Alarm frequency for x-axis peak alarm level, FFT bin number, range: 0 to 255 Table 40. ALM_Y_FREQ Bit Assignments Bits [15:8] [7:0] Description (Default = 0x0000) Not used Alarm frequency for y-axis peak alarm level, FFT bin number, range: 0 to 255 Table 41. ALM_Z_FREQ Bit Assignments Bits [15:8] [7:0] Rev. B | Page 15 of 24 Description (Default = 0x0000) Not used Alarm frequency for z-axis peak alarm level, FFT bin number, range: 0 to 255 ADIS16227 Data Sheet READING OUTPUT DATA The ADIS16227 samples, processes, and stores x, y, and z acceleration data into the FFT buffer and FFT records (if selected). In manual time mode, each axis' record contains 512 samples for each axis. Otherwise, each record contains the 256-point FFT result for each accelerometer axis. Table 42 provides a summary of registers that provide access to processed sensor data. Table 42. Output Data Registers Description Internal power supply Internal temperature Data buffer index pointer FFT record index pointer X-axis accelerometer buffer Y- axis accelerometer buffer Z- axis accelerometer buffer FFT record retrieve command Time stamp, lower word Time stamp, upper word FFT record header information ACCESSING FFT RECORD DATA The FFT records provide flash memory storage for FFT data. The REC_PNTR register (see Table 44) and record retrieve command in GLOB_CMD[13] (see Table 57) provide access to the FFT records, as shown in Figure 16. For example, set REC_PNTR[7:0] = 0x0A (DIN = 0x920A) and GLOB_CMD[13] = 1 (DIN = 0xBF20) to load FFT Record 10 in the FFT buffer for SPI/register access. Table 44. REC_PNTR Bit Descriptions Bits [15:4] [3:0] Description (Default = 0x0000) Not used Data bits FFT FFT RECORD RECORD 0 1 FFT RECORD m FFT RECORD 15 X X Z X O DATA IN BUFFERS LOAD INTO USER OUTPUT REGISTERS X_BUF Z Y Z X Y Z X Y Z SPI REGISTERS FFT BUFFER Figure 16. FFT Record Access DATA FORMAT Table 45 provides the bit assignments for the x_BUF registers. The acceleration data format depends on the range scale and recording mode settings in REC_CTRL. See Table 10 for configuration details and Table 17 for the scale factors associated with each setting. Table 46 provides some data formatting examples for FFT mode, and Table 47 offers some data formatting examples for the16-bit twos complement format used in manual time mode. Table 45. X_BUF, Y_BUF, Z_BUF Bit Descriptions Bits [15:0] Y_BUF 0 Y m = REC_PNTR GLOB_CMD[13] = 1 B SO After completing an FFT event and updating the data buffer, the ADIS16227 loads the first data samples from the data buffer into the x_BUF registers (see Table 45) and sets the buffer index pointer (BUF_PNTR) to 0x0000. The index pointer determines which data samples load into the x_BUF registers. For example, writing 0x009F to the BUF_PNTR register (DIN = 0x9100, DIN = 0x909F) causes the 160th sample in each data buffer location to load into the x_BUF registers. The index pointer increments with every x_BUF read command, which causes the next set of capture data to load into each capture buffer register automatically. This enables a process-efficient method for reading all 256 samples in a record, using sequential reads commands, without having to manipulate BUF_PNTR. Y 09425-019 READING DATA FROM THE DATA BUFFER Description (Default = 0x0000) Not used Data bits TE Address 0x0A 0x0C 0x10 0x12 0x14 0x16 0x18 0x3E 0x4C 0x4E 0x76 Bits [15:9] [8:0] LE Register SUPPLY_OUT TEMP_OUT BUF_PNTR REC_PNTR X_BUF Y_BUF Z_BUF GLOB_CMD TIME_STAMP_L TIME_STAMP_H REC_INFO Table 43. BUF_PNTR Bit Descriptions Description (Default = 0x8000) Acceleration buffer registers Z_BUF Table 46. FFT Mode, 0 g to 5 g Range, Data Format Examples BUF_PNTR X-AXIS Y-AXIS Z-AXIS ACCELEROMETER ACCELEROMETER ACCELEROMETER FFT FFT FFT BUFFER BUFFER BUFFER Acceleration (mg) 4999.9237 7.63 0.1526 0.0763 0 256/512 FFT ANALYSIS INTERNAL SAMPLING SYSTEM SAMPLES, PROCESSES, AND STORES DATA IN FFT BUFFERS. TEMP_OUT 09425-013 SUPPLY_OUT Figure 15. Data Buffer Structure and Operation Rev. B | Page 16 of 24 LSB 65,535 100 2 1 0 Hex 0xFFFF 0x0064 0x0002 0x0001 0x0000 Binary 1111 1111 1111 1111 0000 0000 0110 0100 0000 0000 0000 0010 0000 0000 0000 0001 0000 0000 0000 0000 Data Sheet ADIS16227 Acceleration (mg) +70,000 +1001.358 +4.7684 +2.3842 0 -2.3842 -4.7684 -1001.358 -70,000 LSB +29,360 +420 +2 +1 0 -1 -2 -420 -29,360 Hex 0x72B0 0x01A4 0x0002 0x0001 0x0000 0xFFFF 0xFFFE 0xFE5C 0x8D50 Binary 0111 0010 1011 0000 0000 0001 1010 0100 0000 0000 0000 0010 0000 0000 0000 0001 0000 0000 0000 0000 1111 1111 1111 1111 1111 1111 1111 1110 1111 1110 0101 1100 1000 1101 0101 0000 POWER SUPPLY/TEMPERATURE Table 48. SUPPLY_OUT Bits Descriptions Bits [15:12] [11:0] Description (Default = 0x8000) Not used Power supply, binary, +3.3 V = 0xA8F, 1.22 mV/LSB B SO Table 49. Power Supply Data Format Examples Supply Level (V) 3.6 3.3 + 0.0012207 3.3 3.3 - 0.0012207 3.15 LSB 2949 2704 2703 2702 2580 Hex 0xB85 0xA90 0xA8F 0xA8E 0xA14 Binary 1011 1000 0101 1010 1001 0000 1010 1000 1111 1010 1000 1110 1010 0001 0100 Table 50. TEMP_OUT Bit Descriptions Description (Default = 0x8000) Not used Temperature data, offset binary, 1278 LSB = +25C, -0.47C/LSB O Bits [15:12] [11:0] Table 51. Internal Temperature Data Format Examples Temperature (C) 125 25 + 0.47 25 25 - 0.047 0 -40 LSB 1065 1277 1278 1279 1331 1416 Hex 0x429 0x4FD 0x4FE 0x4FF 0x533 0x588 Each FFT record has an FFT header, which contains information that fills all of the registers listed in Table 52. The information in these registers contains recording time, record configuration settings, status/error flags, and several alarm outputs. The registers listed in Table 52 update with every record event and also update with record-specific information when using GLOB_CMD[13] to retrieve a data set from the FFT record. Table 52. FFT Header Register Information Register DIAG_STAT ALM_X_STAT ALM_Y_STAT ALM_Z_STAT ALM_X_PEAK ALM_Y_PEAK ALM_Z_PEAK TIME_STAMP_L TIME_STAMP_H ALM_X_FREQ ALM_Y_FREQ ALM_Z_FREQ REC_INFO Address 0x3C 0x40 0x42 0x44 0x46 0x48 0x4A 0x4C 0x4E 0x70 0x72 0x74 0x76 LE During every acceleration recording process, the ADIS16227 also measures power supply and internal temperature. It takes a 5.12 ms record of power supply measurements at a sample rate of 50 kHz and takes 64 samples of internal temperature data over a period of 1.7 ms. The average of the power supply and internal temperature loads into the SUPPLY_OUT and TEMP_OUT registers, respectively. FFT EVENT HEADER Binary 0100 0010 1001 0100 1111 1101 0100 1111 1110 0100 1111 1111 0101 0011 0011 0101 1000 1000 Description Alarm status X-alarm status Y-alarm status Z-alarm status X-alarm peak Y-alarm peak Z-alarm peak Time stamp, lower word Time stamp, upper word X-alarm frequency of peak alarm Y-alarm frequency of peak alarm Z-alarm frequency of peak alarm FFT record header information TE Table 47. Acceleration Format, Time Domain, 0 g to 70 g Range The REC_INFO register (see Table 53) captures the settings associated with the current FFT record. Table 53. REC_INFO Bit Descriptions Bits [15:14] [13:12] [11:10] [9] [8:0] Description (Default = 0x0000) Sample rate setting: 00 = SR0, 01 = SR1, 10 = SR2, 11 = SR3 Window setting: 00 = rectangular, 01 = Hanning, 10 = flat top, 11 = N/A Signal range: 00 = 0 g to 1 g, 01 = 0 g to 5 g, 10 = 0 g to 20 g, 11 = 0 g to 70 g Not used FFT averages, range: 1 to 256 The TIME_STAMP_x registers (see Table 54 and Table 55) provide a relative time stamp, which identifies the time for the current FFT record. Table 54. TIME_STMP_L Bit Descriptions Bits [15:0] Description (Default = 0x0000) Time stamp, low integer, binary, seconds Table 55. TIME_STMP_H Bit Descriptions Bits [15:0] Rev. B | Page 17 of 24 Description (Default = 0x0000) Time stamp, high integer, binary, seconds ADIS16227 Data Sheet SYSTEM TOOLS STATUS/ERROR FLAGS Table 56. System Tool Register Addresses Register Name FLASH_CNT DIO_CTRL GPIO_CTRL DIAG_STAT GLOB_CMD LOT_ID1 LOT_ID2 PROD_ID SERIAL_NUM Address 0x00 0x36 0x38 0x3C 0x3E 0x52 0x54 0x56 0x58 Description Flash write cycle count Digital I/O configuration General-purpose I/O control Status, error flags Global commands Lot Identification Code 1 Lot Identification Code 2 Product identification Serial number GLOBAL COMMANDS Table 57. GLOB_CMD Bit Descriptions [12] [11] [10] [9] [8] [7] [6] [5] [4] [3] [2] [1] [0] Bits [15] [14] [13] [12] [11] [10] [9] [8] [7] [6] [5] [4] Execution Time 35 s 40 s B SO [13] Description Clear x_NULL registers Retrieve spectral alarm band information from the ALM_PNTR setting Restore record data from flash memory Save spectral alarm band registers to flash memory Record start/stop Set BUF_PNTR = 0x0000 Clear spectral alarm band registers from flash Clear records Software reset Save registers to flash memory Flash test, compare sum of flash memory with factory value Clear DIAG_STAT register Restore factory register settings and clear the capture buffers Self-test, result in DIAG_STAT[5] Power-down Autonull O Bits [15] [14] Table 58. DIAG_STAT Bit Descriptions Description (Default = 0x0000) Not used System alarm flag Z-axis, Spectral Alarm 2 flag Y-axis, Spectral Alarm 2 flag X-axis, Spectral Alarm 2 flag Z-axis, Spectral Alarm 1 flag Y-axis, Spectral Alarm 1 flag X-axis, Spectral Alarm 1 flag Data ready/busy indicator (0 = busy, 1 = data ready) Flash test result, checksum flag Self-test diagnostic error flag Recording escape flag, indicates use of the SPI-driven interruption command, 0xE8 SPI communication failure, (SCLKs even multiple of 16) Flash update failure Power supply above 3.625 V Power supply below 3.125 V LE The GLOB_CMD register provides an array of single-write commands for convenience. Setting the assigned bit (see Table 57) to 1 activates each function. When the function completes, the bit restores itself to 0. For example, clear the capture buffers by setting GLOB_CMD[8] = 1 (DIN = 0xBF01). All of the commands in the GLOB_CMD register require the power supply be within normal limits for the execution times listed in Table 57. The DIAG_STAT register (see Table 58) provides a number of status/error flags that reflect the conditions observed in a recording during SPI communication and diagnostic tests. A 1 indicates an error condition, and all of the error flags are sticky, which means that they remain until they are reset by setting GLOB_CMD[4] = 1 (DIN = 0xBE10) or by starting a new recording event. DIAG_STAT[14:8] indicates which ALM_x_MAGx thresholds were exceeded during a recording event. The flag in DIAG_STAT[3] indicates that the total number of SCLK clocks is not a multiple of 16. TE Table 56 provides an overview of the control registers that provide support for system level functions. 1.9 ms [3] [2] [1] [0] 461 s OPERATION MANAGMENT N/A 36 s 25.8 ms The ADIS16227 SPI port supports two different communication commands while it is processing data or executing a command associated with the GLOB_CMD register: reading DIAG_STAT (DIN = 0x3C00) and the escape code (DIN = 0xE8E8). The SPI ignores all other commands when the processor is busy. 25.9 ms 53.3 ms 29.3 ms 5.6 ms 36 s 80.9 ms Software Busy Indicator Use the DIAG_STAT read command to poll DIAG_STAT[7], which is equal to 0 when the processor is busy and equal to 1 when the processor is idle and data is ready for SPI communications. 32.9 ms N/A 681 ms Rev. B | Page 18 of 24 Data Sheet ADIS16227 Software Escape Code Table 59. DIO_CTRL Bit Descriptions The only SPI command available when the processor is busy is the escape code, which is 0xE8E8. Send this command in a repeating pattern, with a small delay between each write cycle, to the DIN pin, while monitoring DIAG_STAT[7]. The following code example illustrates this process: Bits [15:6] [5:4] DIAG_STAT = 0; DIAG_STAT = read_reg(0x3C); while ((DIAG_STAT & 0x0080) == 0) { write_reg(0xE8E8) delay_us(50) DIAG_STAT = read_reg(0x3C) } [3:2] The DIO_CTRL register (see Table 59) provides configuration control options for the two digital I/O lines, DIO1 and DIO2. Busy Indicator Trigger Input t t 2.6s CAPTURE TIME 09425-014 DIO1 B SO The trigger function provides an input pin for starting record events with a signal pulse. Set DIO_CTRL[7:0] = 0x2F (DIN = 0xB62F) to configure DIO2 as a positive trigger input and keep DIO1 as a busy indicator. To start a trigger, the trigger input signal must transition from low to high and then from high to low. The recording process starts on the high-to-low transition, as shown in Figure 17, and the pulse duration must be at least 2.6 s. DIO2 [0] General-Purpose I/O If DIO_CTRL configures either DIO1 or DIO2 as a generalpurpose digital line, use the GPIO_CTRL register in Table 60 to configure its input/output direction, set the output level when configured as an output, and monitor the status of an input. LE The busy indicator is an output signal that indicates internal processor activity. This signal is active during data recording events or internal processing (GLOB_CMD functions, for example). The factory default setting for DIO_CTRL sets DIO1 as a positive, active high, busy indicator signal. When configured in this manner, use this signal to alert the master processor to read data from data buffers. TE [1] INPUT/OUTPUT FUNCTIONS Description (Default = 0x000F) Not used DIO2 function selection 00 = general-purpose I/O (use GPIO_CTRL) 01 = alarm indicator output (per ALM_CTRL) 10 = trigger input 11 = busy indicator output DIO1 function selection 00 = general-purpose I/O (use GPIO_CTRL) 01 = alarm indicator output (per ALM_CTRL) 10 = trigger input 11 = busy indicator output DIO2 line polarity 1 = active high 0 = active low DIO1 line polarity 1 = active high 0 = active low O Figure 17. Manual Trigger/Busy Indicator Sequence Example Table 60. GPIO_CTRL Bit Descriptions Bits [15:10] [9] [8] [7:2] [1] [0] Alarm Indicator DIO_CTRL[5:2] provide controls for establishing DIO1 and/or DIO2 as a general alarm output indicator, which goes active when any of the flags in DIAG_STAT[13:8] are active. For example, set DIO_CTRL[7:0] = 0x12 (DIN = 0xB612) to configure DIO2 as a generic alarm indicator with an active high polarity. ALM_CTRL[6] (see Table 22) provides an additional control, which enables DIO2 to reflect Alarm 2 and DIO1 to reflect Alarm 1 when they are selected as alarm indicators in DIO_CTRL[5:2]. For example, set DIO_CTRL[7:0] = 0x17 (DIN = 0xB617) and set ALM_CTRL[6] = 1 (DIN = 0xB440) to establish DIO2 as an activehigh Alarm 2 indicator and DIO1 as an active-high Alarm 1 indicator. Set GLOB_CMD[4] = 1 (DIN = 0xBE10) to clear the DIAG_STAT error flags and restore the alarm indicator signal to its inactive state. Description (Default = 0x0000) Not used DIO2 output level 1 = high 0 = low DIO1 output level 1 = high 0 = low Reserved DIO2 direction control 1 = output 0 = input DIO1 direction control 1 = output 0 = input SELF-TEST Set GLOB_CMD[2] = 1 (DIN = 0xBE02) to run an automatic self-test routine, which reports a pass/fail result to DIAG_STAT[5]. Rev. B | Page 19 of 24 ADIS16227 Data Sheet FLASH MEMORY MANAGEMENT DEVICE IDENTIFICATION Set GLOB_CMD[5] = 1 (DIN = 0xBE20) to run an internal checksum test on the flash memory, which reports a pass/fail result to DIAG_STAT[6]. The FLASH_CNT register (see Table 61) provides a running count of flash memory write cycles. This is a tool for managing the endurance of the flash memory. Figure 18 quantifies the relationship between data retention and junction temperature. Table 62. LOT_ID1 and LOT_ID2 Bit Descriptions Table 61. FLASH_CNT Bit Descriptions Table 64. SERIAL_NUM Bit Descriptions Bits [15:0] Bits [15:0] Table 63. PROD_ID Bit Descriptions Bits [15:0] Description 0x3F63 = 16,227 Description Serial number, lot specific 150 30 40 55 70 85 100 125 135 150 B SO JUNCTION TEMPERATURE (C) 09425-015 300 LE 450 Figure 18. Flash/EE Memory Data Retention O RETENTION (Years) 600 0 Description Lot identification code TE Description Binary counter for writing to flash memory Bits [15:0] Rev. B | Page 20 of 24 Data Sheet ADIS16227 APPLICATIONS INFORMATION MOUNTING GUIDELINES The ADIS16227 provides a threaded hole for a 10-32 UNF machine screw. This hole is 9 mm deep, and the tapped depth is 7 mm. Use a torque of 15 inch-pounds when tightening the 10-32 mounting fastener and make sure that the fastener doesn't bottom-out in the ADIS16227 when tightening. DIO1 and DIO2 signals. The connector is a dual row, 2 mm (pitch) connector that works with a number of ribbon cable systems, including 3M Part Number 152212-0100-GB (ribboncrimp connector) and 3M Part Number 3625/12 (ribbon cable). The LEDs (D1 and D2) provide visual indication of the DIO1 and DIO2 signals. spi_write(BF08h); delay 30ms; Data(0) = spi_reg_read(14h); For n = 0 to 255 Data(n) = spi_reg_read(14h); end B SO n = n + 1; 09425-017 Figure 19. Electrical Schematic LE When the power supply voltage of the ADIS16227 reaches 3.15 V, it executes a start-up sequence that places the device in manual FFT mode. The following code example initiates a manual data recording by setting GLOB_CMD[11] = 1 (DIN = 0xBF08) and reads all 256 samples in the x-axis acceleration buffer, using DIN = 0x1400. The data from the first spi_reg_read is not valid because this command starts the process. The second spi_reg_read command (the first read inside the embedded for loop) produces the first valid data. This code sequence produces CS, SCLK, and DIN signals similar to the ones shown in Figure 11. TE GETTING STARTED O The ADIS16227/PCBZ provides the ADIS16227 on a small printed circuit board (PCB) that simplifies the connection to an existing processor system. A single 10-32 machine screw (Fastener Express, FHS1106-4I2) secures the ADIS16227CMLZ to the interface board. The first set of mounting holes on the interface boards is in the four corners of the PCB and provides clearance for 440 machine screws. The second set of mounting holes provides a pattern that matches the ADISUSBZ evaluation system, using M2 x 0.4 mm machine screws. These boards are made of IS410 material and are 0.063 inches thick. The J1 connector uses Pin 1 through Pin 12 in this pattern. Pin 13 and Pin 14 are for future expansion, but they also provide convenient probe points for the Rev. B | Page 21 of 24 09425-018 INTERFACE BOARD Figure 20. PCB Assembly View and Dimensions ADIS16227 Data Sheet OUTLINE DIMENSIONS 15.20 15.00 SQ 14.80 O 4.04 9 10-32 UNF 7 O 6.10 90, NEAR SIDE 6.00 BCS 1.00 BSC PITCH LE 17.50 NOM TE BOTTOM VIEW TOP VIEW DETAIL A FRONT VIEW B SO SIDE VIEW 15.20 15.00 14.80 0.50 BCS 3.88 NOM 0.45 NOM DETAIL A 4.20 4.10 4.00 06-21-2010-A 0.54 NOM 9.20 9.00 8.80 O Figure 21. 14-Lead Module with Connector Interface (ML-14-2) Dimensions shown in millimeters ORDERING GUIDE Model 1 ADIS16227CMLZ ADIS16227/PCBZ 1 Temperature Range -40C to +125C Package Description 14-Lead Module with Connector Interface Evaluation Board Z = RoHS Compliant Part. Rev. B | Page 22 of 24 Package Option ML-14-2 Data Sheet ADIS16227 O B SO LE TE NOTES Rev. B | Page 23 of 24 ADIS16227 Data Sheet O B SO LE TE NOTES (c)2010-2012 Analog Devices, Inc. All rights reserved. Trademarks and registered trademarks are the property of their respective owners. D09425-0-5/12(B) Rev. B | Page 24 of 24