RXM-900-HP3 - Linx Technologies, Inc.

WIRELESS MADE SIMPLE

APPLICATIONS INCLUDE

Wireless Networks / Data Transfer

Wireless Analog / Audio

Home / Industrial Automation

Remote Access / Control

Remote Monitoring / Telemetry

Long-Range RFID

MIDI Links

Voice / Music / Intercom Links

HP3 SERIES RECEIVER MODULE DATA GUIDE

Revised 1/28/08

DESCRIPTION

The HP3 RF receiver module offers complete

compatibility and numerous enhancements

over previous generations. The HP3 is

designed for the cost-effective, high-

performance wireless transfer of analog or

digital information in the popular 902-928MHz

band. All HP3 Series modules feature eight

parallel selectable channels, but versions are

also available which add serial selection of 100

channels. To ensure reliable performance, the

receiver employs FM / FSK demodulation and

an advanced dual-conversion microprocessor-

controlled synthesized architecture. The

receiver is pin- and footprint-compatible with all

previous generations, but its overall physical size has been reduced. Both SMD and

pinned packages are available. When paired with an HP3 transmitter, a reliable link

is created for transferring analog and digital information up to 1,000 feet. (under

optimal conditions). As with all Linx modules, the HP3 requires no tuning or additional

RF components (except an antenna), making integration straightforward even for

engineers without prior RF experience.

LOT 10000

RXM-900-HP3-SP*

HP SERIES RF RECEIVER

Pin Spacing: 0.1"

0.236"

0.780"

1.940"

0.190"

0.750"

LOT 10000

RXM-900-HP3-SP*

HP SERIES RF RECEIVER

1.950"

SMD Style

SIP Style

Figure 1: Package Dimensions

FEATURES

8 parallel / 100 serial (PS Versions)

user-selectable channels

FM / FSK demodulation for outstanding

performance and noise immunity

Exceptional sensitivity (-100dBm typical)

Wide-range analog capability including

audio (50Hz to 28kHz)

RSSI and Power-down lines

Precision frequency

synthesized architecture

No external RF

components required

Compatible with previous

HP Series modules

High data rate

(up to 56kbps)

Wide supply range

(2.8 to 13.0VDC)

Direct serial interface

Pinned and SMD packages

Wide temperature range

(-30°C to +85°C)

PART # DESCRIPTION

RXM-900-HP3-PPO HP3 Receiver (SIP 8 CH only)

RXM-900-HP3-PPS HP3 Receiver (SIP 8p / 100s CH)

RXM-900-HP3-SPO HP3 Receiver (SMD 8 CH only)

RXM-900-HP3-SPS HP3 Receiver (SMD 8p / 100s CH)

MDEV-900-HP3-PPS-USB HP3 Development Kit (Pinned Pkg.)

MDEV-900-HP3-PPS-RS232 HP3 Development Kit (Pinned Pkg.)

MDEV-900-HP3-SPS-USB HP3 Development Kit (SMD Pkg.)

MDEV-900-HP3-SPS-RS232 HP3 Development Kit (SMD Pkg.)

Receivers are supplied in tubes of 10 pcs.

ORDERING INFORMATION

HIGH-PERFORMANCE

RF MODULE

RXM-900-HP3-xxx

Page 3

-110 -100 -90 -80 -70 -60 -50 -40

1.0

1.5

2.0

2.5

3.0

RF INPUT (dBm)

RSSI VOLTAGE (V)

Figure 5: Worst Case RSSI Response Time

Figure 3: RX Enabled to Valid Data

Figure 6: BER vs. Input Power (typical)

CH1 500mV

1Delta 4.080mS1mS

RX OFF

RX ON >-35dBm

10-6

10-5

10-4

10-3

-92 -93 -94 -95 -96 -97 -98 -99 -100 -101 -102

BER

PIN (dBm)

Figure 4: Receiver RSSI

TYPICAL PERFORMANCE GRAPHS

Page 2

CH1 1.00V CH2 2.00V 500uS

PDN

RX DATA

Delta 1.920mS

ABSOLUTE MAXIMUM RATINGS

Supply Voltage VCC -0.3 to +18.0 VDC

Any Input or Output Pin -0.3 to VCC VDC

Operating Temperature -30 to +85 °C

Storage Temperature -45 to +85 °C

Soldering Temperature +260°C for 10 seconds

*NOTE* Exceeding any of the limits of this section may lead to permanent

damage to the device. Furthermore, extended operation at these maximum

ratings may reduce the life of this device.

ELECTRICAL SPECIFICATIONS

Parameter Designation Min. Typical Max. Units Notes

POWER SUPPLY

Operating Voltage VCC 2.8 3.0 13.0 VDC –

Supply Current ICC 16.0 19.0 21.0 mA 1

Power-Down Current IPDN – 5.6 10.0 µA 2

RECEIVE SECTION

Receive Frequency Range FC902.62 – 927.62 MHz 3

Center Frequency Accuracy -50 +50 kHz

Channel Spacing – – 250 – kHz 3

First IF Frequency – 34.7 – MHz 4

Second IF Frequency – 10.7 – MHz 4

Noise Bandwidth N3DB – 280 – kHz –

Data Rate – 100 – 56,000 bps –

Analog / Audio Bandwidth – 50 – 28,000 Hz 4

Analog / Audio Output Level 0.8 1.1 2.0 VAC 5

Data Output:

Logic Low – 0.0 – 0.5 VDC 6

Logic High – VCC-0.3 – VCC VDC 6

Output Impedance – 17 – kohms –

Data Output Source Current – 230 –

Receiver Sensitivity -94 -100 -107 dBm 8,9

RSSI:

Dynamic Range 60 70 80 dB 4

Gain – 24 – mV/dB 4

Voltage With No Carrier – – 1.6 V 4

Spurious Emissions – -57 – dBm 4

Interference Rejection:

FC±1MHz – 54 – dB 4

FC±5MHz –57–dB4

ANTENNA PORT

RF Input Impedance ROUT –50–Ω4

TIMING

Receiver Turn-On Time:

via VCC T4 – – 7.0 mSec 4

via PDN T3 – – 3.0 mSec 4

Channel Change Time T2 – – 1.5 mSec 4

Max time between transitions T1– – 20 mSec 4

ENVIRONMENTAL

Operating Temperature Range – -30 – +85 °C4

1. Over the entire operating voltage range.

2. With the PDN pin low.

3. Serial mode.

4. Characterized, but not tested.

5. With 1kHz sine wave @ 115kHz transmitter deviation

6. No load.

7. With 1V output drop.

8. For 10-5 @ 9,600bps.

9. At specified center frequency.

Notes

Table 1: HP3 Series Receiver Specifications

PERFORMANCE DATA

These performance parameters

are based on module operation at

25°C from a 3.0VDC supply unless

otherwise noted. Figure 2

illustrates the connections

necessary for testing and

operation. It is recommended all

ground pins be connected to the

ground plane. The pins marked NC

have no electrical connection.

Figure 2: Test / Basic Application Circuit

ANT

GND

GND NC

GND

CS0

CS1 / SS CLOCK NC

CS2 / SS DATA

PDN

RSSI

MODE

VCC

AUDIO NC

DATA

5VDC

Page 4 Page 5

50-ohm RF Input

Analog Ground

No Connection

ANT

GND

Channel Select 0CS0

Channel Select 1 /

Serial Select Clock

CS1 /

SS CLOCK

Channel Select 2 /

Serial Select Data

Received Signal

Strength Indicator

Mode Select

Voltage Input 2.8-13V

1VP-P Analog Output

Digital Data Output

Power Down

(Active Low)

CS2 /

SS DATA

PDN

RSSI

MODE

VCC

AUDIO

DATA

SMD Only No Connection

PDN

470k

VCC

4.7k

RSSI

VCC

RF In

50Ω

CS2

25k

CS1

25k

CS0

25k

2-8

19-36

Pin # Name Equivalent Circuit Description

PIN DESCRIPTIONS

Figure 8: Pin Functions and Equivalent Circuits

PIN ASSIGNMENTS

ANT

GND

N/C

CS0

CS1 / SS CLOCK

CS2 / SS DATA

PDN

RSSI

MODE

VCC

AUDIO

DATA

ANT

GND

GND NC

GND

829

CS0

CS1 / SS CLOCK NC

CS2 / SS DATA

PDN

RSSI

MODE

VCC

AUDIO NC

DATA

18 19

Figure 7: HP3 Series Receiver Pinout

Pin # Name Description

1ANT 50-ohm RF Input

2-8 GND Analog Ground

9NC No Connection

10 CS0 Channel Select 0

11 CS1 / SS

CLOCK

Channel Select 1 / Serial Select Clock. Channel Select 1

when in parallel channel selection mode, clock input for

serial channel selection mode.

12 CS2 / SS

DATA

Channel Select 1 / Serial Select Data. Channel Select 2

when in parallel channel selection mode, data input for

serial channel selection mode.

13 PDN

Power Down. Pulling this line low will place the receiver

into a low-current state. The module will not be able to

receive a signal in this state.

14 RSSI

Received Signal Strength Indicator. This line will supply an

analog voltage that is proportional to the strength of the

received signal.

15 MODE Mode Select. GND for parallel channel selection, VCC for

serial channel selection

16 VCC Supply Voltage

17 AUDIO Recovered Analog Output

18 DATA Digital Data Output. This line will output the demodulated

digital data.

19-36 NC No Connection (SMD only)

Surface-Mount ReceiverPinned Receiver

THEORY OF OPERATION

The HP3 is a high-performance multi-channel, dual-conversion superhet

receiver capable of recovering both analog (FM) and digital (FSK) information

from a matching HP Series transmitter. FM / FSK modulation offers significant

advantages over AM or OOK modulation methods, including increased noise

immunity and the receiver’s ability to capture in the presence of multiple signals.

This is especially helpful in crowded bands, like that in which the HP3 operates.

The single-ended RF port is matched to 50-ohms to support commonly available

antennas, such as those manufactured by Linx. The RF signal coming in from

the antenna is filtered by a Surface Acoustic Wave (SAW) filter to attenuate

unwanted RF energy. A SAW filter provides significantly higher performance

than other filter types, such as an LC bandpass filter.

Once filtered, the signal is amplified by a Low Noise Amplifier (LNA) to increase

the receiver sensitivity and lower the overall noise figure of the receiver. After the

LNA, the signal is mixed with a synthesized local oscillator operating 34.7MHz

below the incoming transmission frequency to produce the first Intermediate

Frequency (IF).

The second conversion and FM demodulation is achieved by a high-

performance IF strip that mixes the 34.7MHz first conversion frequency with

24.0MHz from a precision crystal oscillator. The resulting second IF of 10.7MHz

is then highly amplified in preparation for demodulation.

A quadrature demodulator is used to recover the baseband signal from the

carrier. The demodulated waveform is filtered, after which it closely resembles

the original signal. The signal is routed to the analog output pin and the data

slicer stage, which provides squared digital output via the data output pin. A key

feature of the HP3 is the transparency of its digital output, which does not impose

balancing or duty-cycle requirements within a range of 100bps to 56kbps.

An on-board microcontroller manages receiver functions and greatly simplifies

user interface. The microcontroller reads the channel selection lines and

programs the on-board synthesizer. This frees the designer from complex

programming requirements and allows for manual or software channel selection.

The microcontroller also monitors incoming signal strength and squelches the

data output when the signal is not strong enough for accurate data detection.

Page 7Page 6

Channel

Select

SAW BPF

VCO

PLL

{

4MHz

Int. Osc.

MODE

CS0

CS1

CS2

LNA

34.7M

BPF

10.7MHz

BPF

24MHz

Crystal

Amp

10.7M

BPF

10.7M

Discriminator

Quad

RSSI

Digital

Data

Analog

Data

Limiter

Figure 9: HP3 Series Receiver Block Diagram

POWER-UP SEQUENCE

As previously mentioned, the HP3 is controlled

by an on-board microprocessor. When power

is applied, the microprocessor executes the

receiver start-up sequence, after which the

receiver is ready to receive valid data.

The adjacent figure shows the start-up

sequence. This sequence is executed when

power is applied to the VCC line or when the

PDN line is taken high.

On power-up, the microprocessor reads the

external channel selection lines and sets the

frequency synthesizer to the appropriate

channel. Once the frequency synthesizer has

stabilized, the receiver is ready to accept data.

POWER SUPPLY

The HP3 incorporates a precision, low-dropout

regulator on-board, which allows operation over an

input voltage range of 2.8 to 13 volts DC. Despite this

regulator, it is still important to provide a supply that

is free of noise. Power supply noise can significantly

affect the receiver sensitivity; therefore, providing a

clean power supply for the module should be a high

priority during design.

A 10Ωresistor in series with the supply followed by a

10µF tantalum capacitor from VCC to ground will help in cases where the quality

of supply power is poor. This filter should be placed close to the module’s supply

lines. These values may need to be adjusted depending on the noise present on

the supply line.

USING THE PDN PIN

The Power Down (PDN) line can be used to power down the receiver without the

need for an external switch. This line has an internal pull-up, so when it is held

high or simply left floating, the module will be active.

When the PDN line is pulled to ground, the receiver will enter into a low-current

(<10µA) power-down mode. During this time the receiver is off and cannot

perform any function. It may be useful to note that the startup time coming out

of power-down will be slightly less than when applying VCC.

The PDN line allows easy control of the receiver state from external

components, like a microcontroller. By periodically activating the receiver,

checking for data, then powering down, the receiver’s average current

consumption can be greatly reduced, saving power in battery-operated

applications.

POWER ON

Squelch Data

Output Pin

Determine Mode

Program Freq. Synth

To Default CH. 50

Read Channel

Selection Inputs

Crystal Oscillator

Begins to Operate

Program Frequency

Synthesizer

Ready for

Serial Data Input

Crystal Oscillator

Begins to Work

Determine Squelch

State Data Output Pin

Cycle Here Until More

Data Input

or Mode Change

Determine Squelch

State Data Output Pin

Cycle Here Until

Channel

or Mode Change

Serial ModeParallel Mode

Figure 10: Start-Up Sequence

10Ω

10μF

Vcc IN

Vcc TO

MODULE

Figure 11: Supply Filter

Page 9Page 8

THE DATA OUTPUT

The DATA line outputs recovered digital data. It is an open collector output with

an internal 4.7kΩpull-up. When an RF transmission is not present, or when the

received signal strength is too low to ensure proper demodulation, the data

output is squelched continuous high. This feature supports direct operation with

UARTs, which require their input to be continuously high. An HP3 transmitter and

receiver can be directly connected between two UARTs without the need for

buffering or logical inversion. It should be noted that the squelch level is set just

over the receiver’s internal noise threshold. Any external RF activity above that

threshold will “break squelch” and produce hashing on the line. While the DATA

line will be reliably squelched in low-noise environments, the designer should

always plan for the potential of hashing.

AUDIO OUTPUT

The HP3 Series is optimized for the transmission of serial data; however, it can

also be used very effectively to send a variety of analog signals, including audio.

The ability of the HP3 to send combinations of audio and data opens new areas

of opportunity for creative design.

The analog output of the AUDIO line is valid from 50 Hz to 28 kHz, providing an

AC signal of about 1V peak-to-peak. This is a high impedance output and not

suitable for directly driving low-impedance loads, such as a speaker. In

applications where a low impedance load is to be driven, a buffer circuit should

always be used. For example, in the case of a speaker, a simple op-amp circuit

such as the one shown below can be used to act as an impedance converter.

The transmitter’s modulation voltage is critical, since it determines the carrier

deviation and distortion. The transmitter input level should be adjusted to

achieve the optimum results for your application in your circuit. Please refer to

the transmitter data guide for full details.

When used for audio, the analog output of the receiver should be filtered and

buffered to obtain maximum sound quality. For voice, a 3-4kHz low-pass filter is

often employed. For broader-range sources, such as music, a 12-17kHz cutoff

may be more appropriate. In applications that require high-quality audio, a

compandor may be used to further improve SNR. The HP3 is capable of

providing audio quality comparable to a radio or intercom. For applications where

true high fidelity audio is required, the HP3 will probably not be the best choice,

and a device optimized for audio should be utilized.

HP Analog Out

10k

–

4LM386

0.05uF

1uF

250uF

10 ohm

VCC

Figure 12: Audio Buffer Amplifier

TIMING CONSIDERATIONS

There are four major timing considerations to be aware of when designing with

the HP3 Series receiver. These are shown in the table below.

T1 is the maximum amount of time that can elapse without a data transition. Data

must always be considered in both the analog and the digital domain. Because

the data stream is asynchronous and no particular format is imposed, it is

possible for the data to meet the receiver’s data rate requirement yet violate the

analog frequency requirements. For example, if a 255 (0FF hex) were sent

continuously, the receiver would view the data as a DC level. It would hold that

level until a transition was required to meet the minimum frequency specification.

If no transition occurred, data integrity could not be guaranteed. While no

particular structure or balancing requirement is imposed, the designer must

ensure that both analog and digital signals meet the transition specification.

T2 is the worst-case time needed for a powered-up module to switch between

channels after a valid channel selection. This time does not include external

overhead for loading a desired channel in the serial channel-selection mode.

T3 is the time to receiver readiness from the PDN line going high. Receiver

readiness is determined by valid data on the DATA line. This assumes an

incoming data stream and the presence of stable supply on VCC.

T4 is the time to receiver readiness from the application of VCC. Receiver

readiness is determined by valid data on the DATA line. This assumes an

incoming data stream and the PDN line is high or open.

RECEIVING DATA

Once an RF link has been established, the challenge becomes how to effectively

transfer data across it. While a properly designed RF link provides reliable data

transfer under most conditions, there are still distinct differences from a wired link

that must be addressed. Since the modules do not incorporate internal encoding

or decoding, the user has tremendous flexibility in how data is handled.

It is important to separate the types of transmissions that are technically possible

from those that are legally allowed in the country of operation. Application Notes

AN-00126, AN-00140 and Part 15, Section 249 of the FCC rules should be

reviewed for details on acceptable transmission content in the U.S.

If you want to transfer simple control or status signals (such as button presses)

and your product does not have a microprocessor or you wish to avoid protocol

development, consider using an encoder / decoder IC set. These chips are

available from several manufacturers, including Linx. They take care of all

encoding and decoding functions and provide a number of data lines to which

switches can be directly connected. Address bits are usually provided for

security and to allow the addressing of multiple receivers independently. These

ICs are an excellent way to bring basic remote control products to market quickly

and inexpensively. It is also a simple task to interface with inexpensive

microprocessors or one of many IR, remote control, DTMF, or modem ICs.

Parameter Description Max.

T1 Time between DATA output transitions 20.0mS

T2 Channel change time (time to valid data) 1.5mS

T3 Receiver turn-on time via PDN 3.0mS

T4 Receiver turn-on time via VCC 7.0mS

Page 11Page 10

*See NOTE on previous page.

SERIAL CHANNEL SELECTION TABLE

CHANNEL TX FREQUENCY RX LO CHANNEL TX FREQUENCY RX LO

0 902.62 867.92 51 915.37 880.67

1 902.87 868.17 52 915.62 880.92

2 903.12 868.42 53 915.87 881.17

3 903.37 868.67 54 916.12 881.42

4 903.62 868.92 55 916.37 881.67

5 903.87 869.17 56 916.62 881.92

6 904.12 869.42 57 916.87 882.17

7 904.37 869.67 58 917.12 882.42

8 904.62 869.92 59 917.37 882.67

9 904.87 870.17 60 917.62 882.92

10 905.12 870.42 61 917.87 883.17

11 905.37 870.67 62 918.12 883.42

12 905.62 870.92 63 918.37 883.67

13 905.87 871.17 64 918.62 883.92

14 906.12 871.42 65 918.87 884.17

15 906.37 871.67 66 919.12 884.42

16 906.62 871.92 67 919.37 884.67

17 906.87 872.17 68 919.62 884.92

18 907.12 872.42 69 919.87 885.17

19 907.37 872.67 70 920.12 885.42

20 907.62 872.92 71 920.37 885.67

21 907.87 873.17 72 920.62 885.92

22 908.12 873.42 73 920.87 886.17

23 908.37 873.67 74 921.12 886.42

24 908.62 873.92 75 921.37 886.67

25 908.87 874.17 76 921.62 886.92

26 909.12 874.42 77 921.87 887.17

27 909.37 874.67 78 922.12 887.42

28 909.62 874.92 79 922.37 887.67

29 909.87 875.17 80 922.62 887.92

30 910.12 875.42 81 922.87 888.17

31 910.37 875.67 82 923.12 888.42

32 910.62 875.92 83 923.37 888.67

33 910.87 876.17 84 923.62 888.92

34 911.12 876.42 85 923.87 889.17

35 911.37 876.67 86 924.12 889.42

36 911.62 876.92 87 924.37 889.67

37 911.87 877.17 88 924.62 889.92

38 912.12 877.42 89 924.87 890.17

39 912.37 877.67 90 925.12 890.42

40 912.62 877.92 91 925.37 890.67

41 912.87 878.17 92 925.62 890.92

42 913.12 878.42 93 925.87 891.17

43 913.37 878.67 94 926.12 891.42

44 913.62 878.92 95 926.37 891.67

45 913.87 879.17 96 926.62 891.92

46 914.12 879.42 97 926.87 892.17

47 914.37 879.67 98 927.12 892.42

48 914.62 879.92 99 927.37 892.67

49 914.87 880.17 100 927.62 892.92

50* 915.12 880.42 = Also available in Parallel Mode

CHANNEL SELECTION

Parallel Selection

All HP3 receiver models feature eight

parallel selectable channels. Parallel

Mode is selected by grounding the

MODE line. In this mode, channel

selection is determined by the logic

states of pins CS0, CS1, and CS2, as

shown in the adjacent table. A ‘0’

represents ground and a ‘1’ the positive supply. The on-board microprocessor

performs all PLL loading functions, eliminating external programming and

allowing channel selection via DIP switches or a product’s processor.

Serial Selection

In addition to the Parallel Mode, PS versions of the HP3 also feature 100 serially

selectable channels. The Serial Mode is entered when the MODE line is left open

or held high. In this condition, CS1 and CS2 become a synchronous serial port,

with CS1 serving as the clock line and CS2 as the data line. The module is easily

programmed by sending and latching the binary number (0 to 100) of the desired

channel (see the adjacent Serial Channel Selection Table). With no additional

effort, the module’s microprocessor handles the complex PLL loading functions.

The Serial Mode is

straightforward; however,

minimum timings and bit

order must be followed.

Loading is initiated by

taking the clock line high

and the data line low as

shown. The eight-bit

channel number is then

clocked-in one bit at a

time, with the LSB first.

There is no maximum time for this process, only the minimum times that must be

observed. After the eighth bit, both the clock and data lines should be taken high

to trigger the automatic data latch. A typical software routine can complete the

loading sequence in under 200uS. Sample code is available on the Linx website.

NOTE: When the module is powered up in the Serial Mode, it will default to channel 50 until changed

by user software. This allows testing apart from external programming and prevents out-of-band

operation. When programmed properly, the dwell time on this default channel can be less than 200uS.

Channel 50 is not counted as a usable channel since data errors may occur as transmitters also default

to channel 50 on startup. If a loading error occurs, such as a channel number >100 or a timing problem,

the receiver will default to serial channel 0. This is useful for debugging as it verifies serial port activity.

Table 2: Parallel Channel Selection Table

Variable Data

Note 3

Note 2

Note 1

12345678

25µs

5µs

8µs T4

5µs

Data

Clock

1ms

(T0) Time between packets or prior to data startup ................................1mS min.

(T1) Data-LO / Clock-HI to Data-LO / Clock-LO .......................................25

S min.

(T2) Clock-LO to Clock-HI ...........................................................................5

S min.

(T3) Clock-HI to Clock-LO ...........................................................................8

S min.

(T4) Data-HI / Clock-HI .................................................................................5

S min.

Total Packet Time ......................................................................................157

S min.

1) Loading begins when clock line is high and data line is taken low

2) Ensure that edge is fully risen prior to high-clock transition

3) Both lines high triggers automatic latch

Figure 13: PLL Serial Data Timing

CS2 CS1 CS0 Channel Frequency

0 0 0 0 903.37

0 0 1 1 906.37

0 1 0 2 907.87

0 1 1 3 909.37

1 0 0 4 912.37

1 0 1 5 915.37

1 1 0 6 919.87

1 1 1 7 921.37

Page 13Page 12

TYPICAL APPLICATIONS

The figure below shows a typical RS-232 circuit using the HP3 Series receiver

and a Maxim MAX232. The receiver outputs a serial data stream and the

MAX232 converts that to RS-232 compliant signals. The MODE line is grounded

so the channels are selected by the DIP switches.

The figure below shows a circuit using the QS Series USB module. The QS

converts the data from the receiver into USB compliant signals to be sent to a

PC. The MODE line is high, so the module is in Serial Channel Select mode. The

RTS and DTR lines are used to load the channels. Application Note AN-00155

shows sample source code that can be adapted to use on a PC. The QS Series

Data Guide and Application Note AN-00200 discuss the hardware and software

set-up required for QS Series modules.

The receiver can also be connected to a microcontroller, which will interpret the

data and take specific actions. A UART may be employed or an I / O line may be

used to continuously monitor the DATA line for a valid packet. The receiver may

be connected directly to the microcontroller without the need for buffering or

amplification.

Figure 14: HP3 Receiver and MAX232 IC

4.7

MAX2

4.7

DB-

4.7

V+

V-

R2IN

OUT

T2IN

T1IN

OUT

R1IN

OUT

ANT

GND

GND NC

GND

829

CS0

CS1 / SS CLOCK NC

CS2 / SS DATA

PDN

RSSI

MODE

VCC

AUDIO NC

DATA

18 19

B-

GND

DAT -

GND

ANT

GND

GND NC

GND

CS0

CS1 / SS CLOCK NC

CS2 / SS DATA

PDN

RSSI

MODE

VCC

AUDIO NC

DATA

18 19

SDM-USB-QS

USBDP

USBDM

GND D

DATA

DTR

TX_IND

VCC

SUSP_IND

RX_IND

485_TX

Figure 15: HP3 Receiver and Linx QS Series USB Module

PROTOCOL GUIDELINES

While many RF solutions impose data formatting and balancing requirements,

Linx RF modules do not encode or packetize the signal content in any manner.

The received signal will be affected by such factors as noise, edge jitter, and

interference, but it is not purposefully manipulated or altered by the modules.

This gives the designer tremendous flexibility for protocol design and interface.

Despite this transparency and ease of use, it must be recognized that there are

distinct differences between a wired and a wireless environment. Issues such as

interference and contention must be understood and allowed for in the design

process. To learn more about protocol considerations, we suggest you read Linx

Application Note AN-00160.

Errors from interference or changing signal conditions can cause corruption of

the data packet, so it is generally wise to structure the data being sent into small

packets. This allows errors to be managed without affecting large amounts of

data. A simple checksum or CRC could be used for basic error detection. Once

an error is detected, the protocol designer may wish to simply discard the corrupt

data or implement a more sophisticated scheme to correct it.

INTERFERENCE CONSIDERATIONS

The RF spectrum is crowded and the potential for conflict with other unwanted

sources of RF is very real. While all RF products are at risk from interference, its

effects can be minimized by better understanding its characteristics.

Interference may come from internal or external sources. The first step is to

eliminate interference from noise sources on the board. This means paying

careful attention to layout, grounding, filtering, and bypassing in order to

eliminate all radiated and conducted interference paths. For many products, this

is straightforward; however, products containing components such as switching

power supplies, motors, crystals, and other potential sources of noise must be

approached with care. Comparing your own design with a Linx evaluation board

can help to determine if and at what level design-specific interference is present.

External interference can manifest itself in a variety of ways. Low-level

interference will produce noise and hashing on the output and reduce the link’s

overall range.

High-level interference is caused by nearby products sharing the same

frequency or from near-band high-power devices. It can even come from your

own products if more than one transmitter is active in the same area. It is

important to remember that only one transmitter at a time can occupy a

frequency, regardless of the coding of the transmitted signal. This type of

interference is less common than those mentioned previously, but in severe

cases it can prevent all useful function of the affected device.

Although technically it is not interference, multipath is also a factor to be

understood. Multipath is a term used to refer to the signal cancellation effects

that occur when RF waves arrive at the receiver in different phase relationships.

This effect is a particularly significant factor in interior environments where

objects provide many different signal reflection paths. Multipath cancellation

results in lowered signal levels at the receiver and, thus, shorter useful distances

for the link.

BOARD LAYOUT GUIDELINES

If you are at all familiar with RF devices, you may be concerned about

specialized board layout requirements. Fortunately, because of the care taken by

Linx in designing the modules, integrating them is very straightforward. Despite

this ease of application, it is still necessary to maintain respect for the RF stage

and exercise appropriate care in layout and application in order to maximize

performance and ensure reliable operation. The antenna can also be influenced

by layout choices. Please review this data guide in its entirety prior to beginning

your design. By adhering to good layout principles and observing some basic

design rules, you will be on the path to RF success.

The adjacent figure shows the suggested

PCB footprint for the module. The actual pad

dimensions are shown in the Pad Layout

section of this manual. A ground plane (as

large as possible) should be placed on a

lower layer of your PC board opposite the

module. This ground plane can also be critical

to the performance of your antenna, which will

be discussed later. There should not be any

ground or traces under the module on the

same layer as the module, just bare PCB.

During prototyping, the module should be soldered to a properly laid-out circuit

board. The use of prototyping or “perf” boards will result in horrible performance

and is strongly discouraged.

No conductive items should be placed within 0.15in of the module’s top or sides.

Do not route PCB traces directly under the module. The underside of the module

has numerous signal-bearing traces and vias that could short or couple to traces

on the product’s circuit board.

The module’s ground lines should each have their own via to the ground plane

and be as short as possible.

AM / OOK receivers are particularly subject to noise. The module should, as

much as reasonably possible, be isolated from other components on your PCB,

especially high-frequency circuitry such as crystal oscillators, switching power

supplies, and high-speed bus lines. Make sure internal wiring is routed away

from the module and antenna, and is secured to prevent displacement.

The power supply filter should be placed close to the module’s VCC line.

In some instances, a designer may wish to encapsulate or “pot” the product.

Many Linx customers have done this successfully; however, there are a wide

variety of potting compounds with varying dielectric properties. Since such

compounds can considerably impact RF performance, it is the responsibility of

the designer to carefully evaluate and qualify the impact and suitability of such

materials.

The trace from the module to the antenna should be kept as short as possible.

A simple trace is suitable for runs up to 1/8-inch for antennas with wide

bandwidth characteristics. For longer runs or to avoid detuning narrow bandwidth

antennas, such as a helical, use a 50-ohm coax or 50-ohm microstrip

transmission line as described in the following section.

Page 15Page 14

GROUND PLANE

ON LOWER LAYER

GROUND PLANE

ON LOWER LAYER

Figure 16: Suggested PCB Layout

Dielectric Constant Width/Height (W/d) Effective Dielectric

Constant

Characteristic

Impedance

4.80 1.8 3.59 50.0

4.00 2.0 3.07 51.0

2.55 3.0 2.12 48.0

Trace

Board

Ground plane

Figure 17: Microstrip Formulas

MICROSTRIP DETAILS

A transmission line is a medium whereby RF energy is transferred from one

place to another with minimal loss. This is a critical factor, especially in high-

frequency products like Linx RF modules, because the trace leading to the

module’s antenna can effectively contribute to the length of the antenna,

changing its resonant bandwidth. In order to minimize loss and detuning, some

form of transmission line between the antenna and the module should be used,

unless the antenna can be placed very close (<1/8in.) to the module. One

common form of transmission line is a coax cable, another is the microstrip. This

term refers to a PCB trace running over a ground plane that is designed to serve

as a transmission line between the module and the antenna. The width is based

on the desired characteristic impedance of the line, the thickness of the PCB,

and the dielectric constant of the board material. For standard 0.062in thick FR-

4 board material, the trace width would be 111 mils. The correct trace width can

be calculated for other widths and materials using the information below. Handy

software for calculating microstrip lines is also available on the Linx website,

www.linxtechnologies.com.

PAD LAYOUT

The following pad layout diagram is designed to facilitate both hand and

automated assembly.

PRODUCTION GUIDELINES

The modules are housed in a hybrid SMD package that supports hand or

automated assembly techniques. Since the modules contain discrete

components internally, the assembly procedures are critical to ensuring the

reliable function of the modules. The following procedures should be reviewed

with and practiced by all assembly personnel.

HAND ASSEMBLY

Pads located on the bottom of the

module are the primary mounting

surface. Since these pads are

inaccessible during mounting,

castellations that run up the side of

the module have been provided to

facilitate solder wicking to the

module’s underside. This allows for

very quick hand soldering for

prototyping and small volume

production.

If the recommended pad guidelines have been followed, the pads will protrude

slightly past the edge of the module. Use a fine soldering tip to heat the board

pad and the castellation, then introduce solder to the pad at the module’s edge.

The solder will wick underneath the module, providing reliable attachment. Tack

one module corner first and then work around the device, taking care not to

exceed the times listed below.

Castellations

PCB Pads

Soldering Iron

Tip

Solder

Absolute Maximum Solder Times

Hand-Solder Temp. TX +225°C for 10 Seconds

Hand-Solder Temp. RX +225°C for 10 Seconds

Recommended Solder Melting Point +180°C

Reflow Oven: +220°C Max. (See adjoining diagram)

Figure 19: Soldering Technique

Page 17Page 16 Page 17

Figure 18: Recommended PCB Layout

0.750

0.090

0.100

0.065

0.030 Dia. Finished

0.100

0.060

Surface-Mount ReceiverPinned Receiver

AUTOMATED ASSEMBLY

For high-volume assembly, most users will want to auto-place the modules. The

modules have been designed to maintain compatibility with reflow processing

techniques; however, due to the their hybrid nature, certain aspects of the

assembly process are far more critical than for other component types.

Following are brief discussions of the three primary areas where caution must be

observed.

Reflow Temperature Profile

The single most critical stage in the automated assembly process is the reflow

stage. The reflow profile below should not be exceeded, since excessive

temperatures or transport times during reflow will irreparably damage the

modules. Assembly personnel will need to pay careful attention to the oven’s

profile to ensure that it meets the requirements necessary to successfully reflow

all components while still remaining within the limits mandated by the modules.

The figure below shows the recommended reflow oven profile for the modules.

Shock During Reflow Transport

Since some internal module components may reflow along with the components

placed on the board being assembled, it is imperative that the modules not be

subjected to shock or vibration during the time solder is liquid. Should a shock

be applied, some internal components could be lifted from their pads, causing

the module to not function properly.

Washability

The modules are wash resistant, but are not hermetically sealed. Linx

recommends wash-free manufacturing; however, the modules can be subjected

to a wash cycle provided that a drying time is allowed prior to applying electrical

power to the modules. The drying time should be sufficient to allow any moisture

that may have migrated into the module to evaporate, thus eliminating the

potential for shorting damage during power-up or testing. If the wash contains

contaminants, the performance may be adversely affected, even after drying.

125°C

185°C

217°C

255°C

235°C

60 12030 150 180 210 240 270 300 330 360090

100

150

200

250

300

Recommended RoHS Profile

Max RoHS Profile

Recommended Non-RoHS Profile

180°C

Temperature (oC)

Time (Seconds)

Figure 20: Maximum Reflow Profile

Page 19Page 18

ANTENNA CONSIDERATIONS

The choice of antennas is a critical

and often overlooked design

consideration. The range,

performance, and legality of an RF link

are critically dependent upon the

antenna. While adequate antenna

performance can often be obtained by

trial and error methods, antenna

design and matching is a complex

task. A professionally designed

antenna, such as those from Linx, will

help ensure maximum performance and FCC compliance.

Linx transmitter modules typically have an output power that is slightly higher

than the legal limits. This allows the designer to use an inefficient antenna, such

as a loop trace or helical, to meet size, cost, or cosmetic requirements and still

achieve full legal output power for maximum range. If an efficient antenna is

used, then some attenuation of the output power will likely be needed. This can

easily be accomplished by using the LADJ line or a T-pad attenuator. For more

details on T-pad attenuator design, please see Application Note AN-00150.

A receiver antenna should be optimized for the frequency or band in which the

receiver operates and to minimize the reception of off-frequency signals. The

efficiency of the receiver’s antenna is critical to maximizing range performance.

Unlike the transmitter antenna, where legal operation may mandate attenuation

or a reduction in antenna efficiency, the receiver’s antenna should be optimized

as much as is practical.

It is usually best to utilize a basic quarter-wave whip until your prototype product

is operating satisfactorily. Other antennas can then be evaluated based on the

cost, size, and cosmetic requirements of the product. You may wish to review

Application Note AN-00500 “Antennas: Design, Application, Performance”

ANTENNA SHARING

In cases where a transmitter and receiver

module are combined to form a transceiver,

it is often advantageous to share a single

antenna. To accomplish this, an antenna

switch must be used to provide isolation

between the modules so that the full

transmitter output power is not put on the

sensitive front end of the receiver. There

are a wide variety of antenna switches that

are cost-effective and easy to use. Among

the most popular are switches from Macom and NEC. Look for an antenna

switch that has high isolation and low loss at the desired frequency of operation.

Generally, the Tx or Rx status of a switch will be controlled by a product’s

microprocessor, but the user may also make the selection manually. In some

cases, where the characteristics of the Tx and Rx antennas need to be different

or antenna switch losses are unacceptable, it may be more appropriate to utilize

two discrete antennas.

Figure 21: Linx Antennas

Antenna

Transmitter

Module

Receiver

Module

0.1μF

GND

VDD

Select

GND

Figure 22: Typical Antenna Switch

GENERAL ANTENNA RULES

The following general rules should help in maximizing antenna performance.

1. Proximity to objects such as a user’s hand, body, or metal objects will cause an

antenna to detune. For this reason, the antenna shaft and tip should be

positioned as far away from such objects as possible.

2. Optimum performance will be obtained

from a 1/4- or 1/2-wave straight whip

mounted at a right angle to the ground

plane. In many cases, this isn’t desirable

for practical or ergonomic reasons, thus,

an alternative antenna style such as a

helical, loop, or patch may be utilized

and the corresponding sacrifice in performance accepted.

3. If an internal antenna is to be used, keep it away from other metal components,

particularly large items like transformers, batteries, PCB tracks, and ground

planes. In many cases, the space around the antenna is as important as the

antenna itself. Objects in close proximity to the antenna can cause direct

detuning, while those farther away will alter the antenna’s symmetry.

4. In many antenna designs, particularly 1/4-wave

whips, the ground plane acts as a counterpoise,

forming, in essence, a 1/2-wave dipole. For this

reason, adequate ground plane area is essential.

The ground plane can be a metal case or ground-fill

areas on a circuit board. Ideally, it should have a

surface area > the overall length of the 1/4-wave

radiating element. This is often not practical due to

size and configuration constraints. In these

instances, a designer must make the best use of the

area available to create as much ground plane as

possible in proximity to the base of the antenna. In cases where the antenna is

remotely located or the antenna is not in close proximity to a circuit board,

ground plane, or grounded metal case, a metal plate may be used to maximize

the antenna’s performance.

5. Remove the antenna as far as possible from potential interference sources. Any

frequency of sufficient amplitude to enter the receiver’s front end will reduce

system range and can even prevent reception entirely. Switching power

supplies, oscillators, or even relays can also be significant sources of potential

interference. The single best weapon against such problems is attention to

placement and layout. Filter the module’s power supply with a high-frequency

bypass capacitor. Place adequate ground plane under potential sources of noise

to shunt noise to ground and prevent it from coupling to the RF stage. Shield

noisy board areas whenever practical.

6. In some applications, it is advantageous to

place the module and antenna away from the

main equipment. This can avoid interference

problems and allows the antenna to be

oriented for optimum performance. Always use

50Ωcoax, like RG-174, for the remote feed.

NUT GROUND PLANE

(MAY BE NEEDED)

CASE

Figure 25: Remote Ground Plane

OPTIMUM

USEABLE NOT RECOMMENDED

Figure 23: Ground Plane Orientation

EDIPOLE

ELEMENT

GROUND

PLANE

VIRTUAL λ/4

DIPOLE

λ/4

VERTICAL λ/4 GROUNDED

ANTENNA (MARCONI)

Figure 24: Dipole Antenna

Page 21Page 20

A whip-style antenna provides outstanding overall performance

and stability. A low-cost whip is can be easily fabricated from a

wire or rod, but most designers opt for the consistent

performance and cosmetic appeal of a professionally-made

model. To meet this need, Linx offers a wide variety of straight

and reduced-height whip-style antennas in permanent and

connectorized mounting styles.

The wavelength of the operational frequency determines an

antenna’s overall length. Since a full wavelength is often quite

long, a partial 1/2- or 1/4-wave antenna is normally employed.

Its size and natural radiation resistance make it well matched to

Linx modules. The proper length for a straight 1/4-wave can be

easily determined using the adjacent formula. It is also possible

to reduce the overall height of the antenna by using a helical

winding. This reduces the antenna’s bandwidth, but is a great

way to minimize the antenna’s physical size for compact

applications. This also means that the physical appearance is

not always an indicator of the antenna’s frequency.

Linx offers a wide variety of specialized antenna styles.

Many of these styles utilize helical elements to reduce the

overall antenna size while maintaining reasonable

performance. A helical antenna’s bandwidth is often quite

narrow and the antenna can detune in proximity to other

objects, so care must be exercised in layout and placement.

Whip Style

Loop Style

L =

234

MHz

Where:

L = length in feet of

quarter-wave length

F = operating frequency

in megahertz

Specialty Styles

A loop- or trace-style antenna is normally printed directly on a

product’s PCB. This makes it the most cost-effective of antenna

styles. The element can be made self-resonant or externally

resonated with discrete components, but its actual layout is

usually product specific. Despite the cost advantages, loop-style

antennas are generally inefficient and useful only for short-range

applications. They are also very sensitive to changes in layout and

PCB dielectric, which can cause consistency issues during

production. In addition, printed styles are difficult to engineer,

requiring the use of expensive equipment, including a network

analyzer. An improperly designed loop will have a high SWR at the

desired frequency, which can cause instability in the RF stage.

Linx offers low-cost planar and chip antennas that mount directly

to a product’s PCB. These tiny antennas do not require testing and

provide excellent performance in light of their small size. They

offer a preferable alternative to the often-problematic “printed”

antenna.

COMMON ANTENNA STYLES

There are literally hundreds of antenna styles and variations that can be

employed with Linx RF modules. Following is a brief discussion of the styles

most commonly utilized. Additional antenna information can be found in Linx

Application Notes AN-00100, AN-00140, and AN-00500. Linx antennas and

connectors offer outstanding performance at a low price.

ONLINE RESOURCES

• Latest News

• Data Guides

• Application Notes

• Knowledgebase

• Software Updates

If you have questions regarding any Linx product and have Internet access,

make www.linxtechnologies.com your first stop. Our website is organized in an

intuitive format to immediately give you the answers you need. Day or night, the

Linx website gives you instant access to the latest information regarding the

products and services of Linx. It’s all here: manual and software updates,

application notes, a comprehensive knowledgebase, FCC information, and much

more. Be sure to visit often!

www.antennafactor.com

The Antenna Factor division of Linx offers

a diverse array of antenna styles, many of

which are optimized for use with our RF

modules. From innovative embeddable

antennas to low-cost whips, domes to

Yagis, and even GPS, Antenna Factor

likely has an antenna for you, or can

design one to meet your requirements.

www.connectorcity.com

Through its Connector City division, Linx offers a wide

selection of high-quality RF connectors, including FCC-

compliant types such as RP-SMAs that are an ideal

match for our modules and antennas. Connector City

focuses on high-volume OEM requirements, which

allows standard and custom RF connectors to be offered

at a remarkably low cost.

www.linxtechnologies.com

Page 23Page 22

ACHIEVING A SUCCESSFUL RF IMPLEMENTATION

Adding an RF stage brings an exciting new

dimension to any product. It also means that

additional effort and commitment will be needed to

bring the product successfully to market. By utilizing

premade RF modules, such as the LR Series, the

design and approval process is greatly simplified. It

is still important, however, to have an objective view

of the steps necessary to ensure a successful RF

integration. Since the capabilities of each customer

vary widely, it is difficult to recommend one

particular design path, but most projects follow steps

similar to those shown at the right.

In reviewing this sample design path, you may

notice that Linx offers a variety of services (such as

antenna design and FCC prequalification) that are

unusual for a high-volume component manufacturer.

These services, along with an exceptional level of

technical support, are offered because we recognize

that RF is a complex science requiring the highest

caliber of products and support. “Wireless Made

Simple” is more than just a motto, it’s our

commitment. By choosing Linx as your RF partner

and taking advantage of the resources we offer, you

will not only survive implementing RF, you may even find the process enjoyable.

HELPFUL APPLICATION NOTES FROM LINX

It is not the intention of this manual to address in depth many of the issues that

should be considered to ensure that the modules function correctly and deliver

the maximum possible performance. As you proceed with your design, you may

wish to obtain one or more of the following application notes, which address in

depth key areas of RF design and application of Linx products. These

applications notes are available online at www.linxtechnologies.com or by

contacting the Linx literature department.

DECIDE TO UTILIZE RF

RESEARCH RF OPTIONS

CHOOSE LINX MODULE

ORDER EVALUATION KIT(S)

TEST MODULE(S) WITH

BASIC HOOKUP

INTERFACE TO CHOSEN

CIRCUIT AND DEBUG

CONSULT LINX REGARDING

ANTENNA OPTIONS AND DESIGN

LAY OUT BOARD

SEND PRODUCTION-READY

PROTOTYPE TO LINX

FOR EMC PRESCREENING

OPTIMIZE USING RF SUMMARY

GENERATED BY LINX

SEND TO PART 15

TEST FACILITY

RECEIVE FCC ID #

COMMENCE SELLING PRODUCT

Typical Steps For

Implementing RF

AN-00100 RF 101: Information for the RF Challenged

AN-00126 Considerations For Operation Within The 902-928MHz Band

AN-00130 Modulation Techniques For Low-Cost RF Data Links

AN-00140 The FCC Road: Part 15 From Concept To Approval

AN-00155 Serial Loading Techniques for the HP Series 3

AN-00160 Considerations For Sending Data Over a Wireless Link

AN-00500 Antennas: Design, Application, Performance

NOTE APPLICATION NOTE TITLE

LEGAL CONSIDERATIONS

When working with RF, a clear distinction must be made between what is technically

possible and what is legally acceptable in the country where operation is intended. Many

manufacturers have avoided incorporating RF into their products as a result of

uncertainty and even fear of the approval and certification process. Here at Linx, our

desire is not only to expedite the design process, but also to assist you in achieving a

clear idea of what is involved in obtaining the necessary approvals to legally market your

completed product.

In the United States, the approval process is actually quite straightforward. The

regulations governing RF devices and the enforcement of them are the responsibility of

the Federal Communications Commission (FCC). The regulations are contained in Title

47 of the Code of Federal Regulations (CFR). Title 47 is made up of numerous volumes;

however, all regulations applicable to this module are contained in Volume 0-19. It is

strongly recommended that a copy be obtained from the Government Printing Office in

Washington or from your local government bookstore. Excerpts of applicable sections are

included with Linx evaluation kits or may be obtained from the Linx Technologies website,

www.linxtechnologies.com. In brief, these rules require that any device that intentionally

radiates RF energy be approved, that is, tested for compliance and issued a unique

identification number. This is a relatively painless process. Linx offers full FCC pre-

screening, and final compliance testing is then performed by one of the many

independent testing laboratories across the country. Many labs can also provide other

certifications that the product may require at the same time, such as UL, Class A / B, etc.

Once your completed product has passed, you will be issued an ID number that is to be

clearly placed on each product manufactured.

Questions regarding interpretations of the Part 2 and Part 15 rules or measurement

procedures used to test intentional radiators, such as Linx RF modules, for compliance

with the technical standards of Part 15, should be addressed to:

Federal Communications Commission

Office of Engineering and Technology Laboratory Division

7435 Oakland Mills Road

Columbia, MD 21046-1609

Phone: (301) 362-3000 Fax: (301) 362-3290 E-Mail: labinfo@fcc.gov

International approvals are slightly more complex, although Linx modules are designed

to allow all international standards to be met. If you are considering the export of your

product abroad, you should contact Linx Technologies to determine the specific suitability

of the module to your application.

All Linx modules are designed with the approval process in mind and thus much of the

frustration that is typically experienced with a discrete design is eliminated. Approval is

still dependent on many factors, such as the choice of antennas, correct use of the

frequency selected, and physical packaging. While some extra cost and design effort are

required to address these issues, the additional usefulness and profitability added to a

product by RF makes the effort more than worthwhile.

NOTE: Linx RF modules are designed as component devices that require

external components to function. The modules are intended to allow for full Part

15 compliance; however, they are not approved by the FCC or any other agency

worldwide. The purchaser understands that approvals may be required prior to

the sale or operation of the device, and agrees to utilize the component in keeping

with all laws governing its use in the country of operation.

LINX TECHNOLOGIES, INC.

159 ORT LANE

MERLIN, OR 97532

PHONE: (541) 471-6256

FAX: (541) 471-6251

www.linxtechnologies.com

U.S. CORPORATE HEADQUARTERS

WIRELESS MADE SIMPLE

Linx Technologies is continually striving to improve the quality and function of its products. For this reason,

we reserve the right to make changes to our products without notice. The information contained in this

Overview Guide is believed to be accurate as of the time of publication. Specifications are based on

representative lot samples. Values may vary from lot-to-lot and are not guaranteed. "Typical" parameters can

and do vary over lots and application. Linx Technologies makes no guarantee, warranty, or representation

regarding the suitability of any product for use in any specific application. It is the customer's responsibility

to verify the suitability of the part for the intended application. NO LINX PRODUCT IS INTENDED FOR USE

IN ANY APPLICATION WHERE THE SAFETY OF LIFE OR PROPERTY IS AT RISK.

Linx Technologies DISCLAIMS ALL WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A

PARTICULAR PURPOSE. IN NO EVENT SHALL LINX TECHNOLOGIES BE LIABLE FOR ANY OF

CUSTOMER'S INCIDENTAL OR CONSEQUENTIAL DAMAGES ARISING IN ANY WAY FROM ANY DEFECTIVE

OR NON-CONFORMING PRODUCTS OR FOR ANY OTHER BREACH OF CONTRACT BY LINX

TECHNOLOGIES. The limitations on Linx Technologies' liability are applicable to any and all claims or

theories of recovery asserted by Customer, including, without limitation, breach of contract, breach of

warranty, strict liability, or negligence. Customer assumes all liability (including, without limitation, liability

for injury to person or property, economic loss, or business interruption) for all claims, including claims

from third parties, arising from the use of the Products. The Customer will indemnify, defend, protect, and

hold harmless Linx Technologies and its officers, employees, subsidiaries, affiliates, distributors, and

representatives from and against all claims, damages, actions, suits, proceedings, demands, assessments,

adjustments, costs, and expenses incurred by Linx Technologies as a result of or arising from any Products

sold by Linx Technologies to Customer. Under no conditions will Linx Technologies be responsible for

losses arising from the use or failure of the device in any application, other than the repair, replacement, or

refund limited to the original product purchase price. Devices described in this publication may contain

proprietary, patented, or copyrighted techniques, components, or materials. Under no circumstances shall

any user be conveyed any license or right to the use or ownership of such items.

Disclaimer

Linx, “Wireless Made Simple”, CipherLinx, and the stylized

CL logo are the trademarks of Linx Technologies, Inc.

Printed in U.S.A.