TRM-xxx-TT Data Guide
Contents
1. 0 15 2 5 3 3 5 5 Supply Voltage V Figure 16 TT Series Transceiver Standby Current Consumption vs Supply Voltage 3 5 m a N al k RSSI Output Voltage V o ul o 81 71 61 51 41 31 21 RF Input Power Level dBm 111 101 91 Figure 17 TT Series Transceiver RSSI Voltage vs Input Power Pin Assignments Pin Descriptions Pin Descriptions Pin Number 1 3 6 11 17 22 28 28 34 39 42 4 4 2 4 5 7 8 37 38 40 41 9 10 12 18 18 19 20 26 Name GND NC SO S7 LVL_ADJ 1 0 Figure 18 TT Series Transceiver Pin Assignments Top View 1 0 Description Ground No Electrical Connection Do not connect any traces to these lines Status Lines Each line can be configured as either an input to register button or contact closures or as an output to control application circuitry Level Adjust This line sets the transmitter output power level Pull high or leave open for the highest power connect to GND through a resistor to lower the power Pin Descriptions Continued Pin Number 21 24 25 2 29 30 31 32 33 35 36 43 Name LATCH EN RESET RSSI POWER DOWN VCC CMD_DATA_IN CMD_DATA_OUT CO ACK OUT C1 PAIR MODE IND ACK EN ANTENNA VO Description If this line is high then the status line outputs are latched a received command to activ2. e Send and receive 2 bytes 16 bits of custom data with each command message and acknowledge message e Gerially initiate transmission of control messages instead of triggering the status line inputs e Set interrupts to notify an external processor when specific events occur such as receiving a control message e Read out the RSSI value for the last received packet and the current ambient RF level e Set the receiver duty cycle for automatically powering on and off to save battery power The serial interface offers a great deal of flexibility for use more complicated designs Please see Reference Guide RG 00103 the TT Series Command Data Interface for details on the CDI A list of the serial commands is shown in Figure 28 for reference Fi Command Data Interface Commands and Parameters g Command Read Write Read NV Program Set Default Configuration Erase All Addresses Transmit Control Data Transmit ACK Transmit AWD Parameter Device Name Firmware Version Serial Number Local Address Status Line I O Mask Latch Mask TX Power Level Control Source Message Select Paired Module Descriptor Duty Cycle O Lines RSSI LADJ odule Status Captured Receive Packet nterrupt Mask Event Flags Description Read the current value in volatile memory If there is no volatile value then the non volatile value is returned Write a new value to volatile memory Read the value in non volat
3. Basic Hardware Operation The following steps describe how to use the TT Series module with hardware only Basic application circuits that correspond to these steps are shown in Figure 21 1 Set the CO and C1 lines opposite on both sides 2 Press the PAIR button on both sides The MODE IND LED begins flashing slowly to indicate that the module is searching for another module 3 Once the pairing is complete the MODE IND LED flashes quickly to indicate that the pairing was successful 4 The modules are now paired and ready for normal use 5 Pressing a status line button on one module the IU activates the corresponding status line output on the second module the RU 6 Taking the ACK EN line high on the RU causes the module to send an acknowledgement to the IU The ACK OUT line on the IU goes high to indicate that the acknowledgement has been received Tying the line to V causes the module to send an acknowledgement as soon as a command message is received This is suitable for basic remote control or command systems No programming is necessary for basic hardware operation The following Sections describe the functions in more detail and the Typical Applications section shows additional example schematics for using the modules Sensor applications can replace the buttons with triggered outputs from sensors A comparator circuit can be used to trigger a line when a sensor reading crosses a threshold providing a warning
4. TECHNOLOGIES TT Series Remote Control and Sensor Transceiver Data Guide Wireless made simple A Warning Linx radio frequency RF products may be used to control machinery or devices remotely including machinery or devices that can cause death bodily injuries and or property damage if improperly or inadvertently triggered particularly in industrial Settings or other applications implicating life safety concerns No Linx Technologies product is intended for use in any application without redundancies where the safety of life or property is at risk The customers and users of devices and machinery controlled with HF products must understand and must use all appropriate safety procedures in connection with the devices including without limitation using appropriate safety procedures to prevent inadvertent triggering by the user of the device and using appropriate security codes to prevent triggering of the remote controlled machine or device by users of other remote controllers Do not use this or any Linx product to trigger an action directly from the data line or RSSI lines without a protocol or encoder decoder to validate the data Without validation any signal from another unrelated transmitter in the environment received by the module could inadvertently trigger the action All RF products are susceptible to RF interference that can prevent communication RF products without frequency agility or hopping implem
5. of commands that performs specific tasks and the other is a set of parameters that are for module configuration and status reporting These are shown in Figure 28 TT Series Transceiver Command Data Interface Reference Guide has full details on each command Some key features available with the serial interface are e Configure the module through software instead of setting the hardware lines e Change the output power providing the ability to lower power consumption when signal levels are good and extend battery life e ndividually set which status lines are inputs and outputs e Individually set status line outputs to operate as momentary or latched e Add or remove specific paired devices e ndividually set Permission Masks that prevent certain paired devices from activating certain status line outputs e Change the module s local address for production or tracking purposes or to replace a lost or broken product e Put the module into a low power state to conserve battery power e Receive the entire control message serially instead of needing to monitor individual status lines Get the IU address for logging access attempts e Receive control messages from unpaired modules allowing for expansion of the system beyond the maximum of 40 paired units Access control and address validation can be undertaken by an external processor or PC with more memory than the module e Serially configure and control acknowledge messages
6. 1 Measured at 3 3V Voo 9 45 lt V lt 5 5 Item Description Minimum Maximum 2 Measured at 25 C 10 V4 x4 5 TXR V POWER DOWN 8 3 Guaranteed by design 11 I lt 8MAQV gt 5V I lt 6mA V gt al iss 4 Characterized but not tested 3 3V I lt 0 8mA V gt 2 5V AB TX Response from Status line while IU in idle 12ms o 12 1 lt 3 5mA Q V 2 5V lt 3mA V i i idle i 3 6 Into a 50 ohm load 1S 3 om coz 9M 1S 8M Go TX Response from Status line while IU RU idle in RX ims 7 No RF interference aN PSU Noo 28y BC RX Initial Response 4ms 50ms 8 Response time is from end of 13 Maximum 80ms if V lt 2 6V command to start of response CD Data Settle Aus Sus El Data Update Delay During Active Session 5ms 25ms Figure 3 Electrical Specifications EG Shutdown Duration 25ms 342ms GH RX MODE IND Drop 6ms 8ms Absolute Maximum Ratings E From module off to V applied 5 2 The module is set as an IU only and is in idle pending status line activation Absolute Maximum Ratings 3 The module is set as an IU and RU and is idling in receive mode pending status line Supply Voltage V 0 3 to 45 5 VDC activation or receipt of a valid packet 4 Maximum 80ms if V lt 2 6V Any Input or Output Pin 0 3 to Vogt 0 3 VDC RF input 9 enn Figure 5 TT Series Transceiver Timings Operating Temperature 40 to 85 ES Storage Temperature 55 to 125 C Exceeding any of the limits of this section may lead to permanent damage to the
7. The duration of the flashes indicates the module s current state Pull this line high to enable the module to send an acknowledgement message after a valid control message has been received 50 ohm RF Antenna Port 1 This line has an internal 100kQ pull up resistor Figure 19 TT Series Transceiver Pin Descriptions Theory of Operation The TT Series transceiver is a low cost high performance synthesized FSK transceiver Its exceptional sensitivity results in outstanding range performance Figure 20 shows a block diagram for the module 1 il ERE DEMOD INTERFACE MD SBIT to PRocESSOR VOLTAGE ISO NIEREAGE CDR TRANSLATION AFC ANTENNA O A He A SS JES e CHARGE 26MHz vecco o ol too LOOP FILTER PUMP PFD osc A DIVIDER DIVIDER f PA RAMP PROFILE i PON DEV I A Le GAUSSIAN MODULATOR FILTER Figure 20 TT Series Transceiver RF Section Block Diagram The TT Series transceiver is designed for operation in the 902 to 928MHz frequency band The RF synthesizer contains a VCO and a low noise fractional N PLL The VCO operates at twice the fundamental frequency to reduce spurious emissions The receive and transmit synthesizers are integrated enabling them to be automatically configured to achieve optimum phase noise modulation
8. 44 44 46 48 50 Additional Testing Requirements Information to the user Product Labeling FCC RF Exposure Statement Antenna Selection Typical Applications Antenna Considerations Helpful Application Notes from Linx Interference Considerations Pad Layout Board Layout Guidelines Microstrip Details Production Guidelines Hand Assembly Automated Assembly General Antenna Rules Common Antenna Styles Regulatory Considerations TT Series Remote Control As and Sensor Transceiver nx D t Guide TECHNOLOGIES m 1 150 Description 29 21 The TT Series transceiver is designed for reliable bi directional long range remote 0 630 T0 control and sensor applications It consists of 16 00 equus ua e 4 IC 5840A TRM900TTA a highly optimized Frequency Hopping Spread Spectrum FHSS RF transceiver and integrated remote control transcoder The FHSS system 01817 allows higher power and therefore longer Pot range than narrowband radios The transceiver Figure 1 Package Dimensions has obtained modular approval for the United States and Canada Eight status lines can be set up in any combination of inputs and outputs for the transfer of button or contact states A selectable acknowledgement indicates that the transmission was successfully received Operating in the 902 to 928MHz frequency band the module achieves a typical sensitivity of 112dBm The base version is capable of generating 12 5dBm transmitter output
9. a valid message is received it locks onto the hopping pattern of the transmitter and asserts the MODE IND line It compares the received status line states to the Permission Mask for the IU to see if the IU is authorized to activate the lines The module sets all authorized outputs to match the received states Only status line outputs are affected by received control packets Received commands to change an input line have no effect The RU then checks the state of the ACK EN line and transmits an acknowledgement packet if it is high It looks for the next valid packet while maintaining the frequency hopping timing As long as an RU is receiving valid commands from a paired IU it will not respond to any other unit Once eight consecutive packets are missed the RU is logically disconnected from the IU and waits for the next valid packet from any IU The Pair Process The Pair process enables two transceivers to communicate with each other Each transceiver has a local 32 bit address that is transmitted with every packet If the address in the received packet is not in the RU s Paired Module List then the transceiver does not respond Adding devices to the authorized list is accomplished through the Pair process or by a serial command Each module can be paired with up to 40 other modules The Pair process is initiated by taking the PAIR line high on both units to be associated Activation can either be a momentary pulse less than two s
10. components to function The purchaser understands that additional 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 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 a completed product For information about regulatory approval read AN 00142 on the Linx website or call Linx Linx designs products with worldwide regulatory approval in mind 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 United States 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 FCC s website the Government Pr
11. cost size and cosmetic requirements of the product Additional details are in Application Note AN 00500 The transceiver includes a U FL connector as well as a line for the antenna connection This offers the designer a great deal of flexibility in antenna selection and location within the end product Linx offers cable assemblies with a U FL connector on one end and several types of standard and FCC compliant reverse polarity connectors on the other end Alternatively the designer may wish to use the pin and route the antenna to a PCB mount connector or even a printed loop trace antenna This gives the designer the greatest ability to optimize performance and cost within the design Note Either the connector or the line can be used for the antenna but not both at the same time 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 We recommend reading the application notes listed in Figure 34 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 Linx Helpful Application Note Titles Note Number Note Title AN 00100 RF 101 Information for the RF Challenged AN 00126 Considerations for Operation Within the 902 928MHz Band AN 00130 Modulation
12. power Any additional current sourcing or sinking can change this voltage and result in a different power level The power level should be checked to confirm that it is set as expected Even in designs where attenuation is not anticipated it is a good idea to place resistor pads connected to L VL ADJ and ground so that it can be used if needed Figure 23 shows the 196 tolerance resistor value that is needed to set each power level and gives the approximate output power for each level The output power levels are approximate and may vary part to part 24 25 Receiver Duty Cycle The module can be configured to automatically power on and off while in receive mode Instead of being powered on all the time looking for transmissions from an lU the receiver can wake up look for data and go back to sleep for a configurable amount of time If it wakes up and receives valid data then it stays on and goes back to sleep when the data stops This significantly reduces the amount of current consumed by the receiver It also increases the time from activating the IU to getting a response from the RU The duty cycle is controlled by the Duty Cycle serial command through the Command Data Interface DCycle sets the number of seconds between receiver turn on points as shown in Figure 24 i DCycle i sav i i KeepOn Activity Z ON i E Standby 7 4 ON Figure 24 Receiver Duty Cycle The
13. 0 2 55 3 0 2 12 48 8 Figure 37 Example Microstrip Calculations Production Guidelines The module is housed in a hybrid SMD package that supports hand and 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 Soldering Iron mounting surface Figure 38 Tip Since these pads are inaccessible during mounting castellations 3 that run up the side of the module Solder have been provided to facilitate PCB Pads solder wicking to the module s underside This allows for very Figure 38 Soldering Technique 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 in Figure 39 Castellations Warning Pay attention to the absolute maximum solder times Absolute Maximum Solder Times Hand Solder Temperature 427 C for 10 seconds for lead f
14. 0ms when the address table is full and ON for 100ms OFF for 100ms ON for 100ms OFF for 300ms Remote Pair Error when the remote unit s address table is full and a Pair cannot be completed ON for 100ms OFF for 200ms ON for 100ms when the Pair process is canceled ON for 600ms OFF for 100ms ON for 200ms OFF for 100ms another unit cannot be added u Pair Canceled Reset ON for 200ms and OFF for 100ms when the reset sequence is Acknowledgement recognized Extended Pair Solid ON when the pairing operation is completed and waiting for Completed the PAIR line to go low Figure 22 MODE IND Timing Reset to Factory Default The transceiver is reset to factory default by taking the Pair line high briefly 4 times then holding Pair high for more than 3 seconds Each brief interval must be high 0 1 to 2 seconds and low 0 1 to 2 seconds 1 second nominal high low cycle The sequence helps prevent accidental resets Once the sequence is recognized the MODE ND line blinks the Reset Acknowledgement defined in Figure 22 until the PAIR line goes low After the input goes low the configuration is initialized Factory reset also clears the Paired Module table but does not change the local address If the PAIR input timing doesn t match the reset sequence timing the module reverts to normal operation without a reset or pairing Using the RSSI Line The module s Received Signal Strength Indicator RSSI line outputs a volta
15. D 2 8 5 10 15 TX Output Power dBm Figure 10 TT Series Transceiver Average Current Consumption vs Transmitter Output Power at 5 5V 23 22 5 22 21 5 21 TX Icc mA 20 5 20 19 5 2 5 3 3 5 4 4 5 5 5 5 Supply Voltage V Figure 11 TT Series Transceiver TX Current Consumption vs Supply Voltage at Max Power 16 5 85 C 16 ee ee a a _ 15 5 E 15 ee eS o Q x 14 5 m 14 13 5 13 25 27 29 31 33 35 37 39 41 43 45 47 49 51 53 55 Supply Voltage V Figure 12 TT Series Transceiver TX Current Consumption vs Supply Voltage at OdBm 13 5 40 C SSS eee 13 25 C 12 5 ee Transmitter Output Power dBm 11 T 1 2 5 3 3 5 5 Supply Voltage V Figure 13 TT Series Transceiver Transmitter Output Power vs Supply Voltage 17 5 17 16 5 AA OO o m 15 5 15 14 5 o 14 RX Icc mA 13 5 T T T T T T T T T 1 2 5 2 8 3 1 3 4 3 7 4 4 3 4 6 4 9 5 2 5 5 Supply Voltage V Figure 14 TT Series Transceiver RX Current Consumption vs Supply Voltage 10 T pu 2 5VDC E 3 0VDC 8 8 3VDC o 14 5 0vDC POIL A 0 1 0 15 30 45 60 75 90 105 120 135 150 165 180 195 210 225 240 255 Duty Cycle s Figure 15 TT Series Transceiver Average RX Current Consumption vs Duty Cycle 0 35 0 3 0 25 0 2 Standby lcc mA
16. ESET EMPSDATAEQUT 100k 91k 1 i GND GND ND XI LATCH EN co m 48 RESET CMD_DATA_OUT vcc o s7 CMD DATA IN i DAD GND S6 S5 GND lt GND GND 18 S4 vcc i EA vocho POWER_DOWN 19 E Cse S6 S5 NDA ENE S4 vcc TRM XXX TT 217 assi POWER DOWN GND 224 GND GND vech 0 TRM XXX TT NOS 100k Figure 31 TT Series Transceiver Basic Application Circuit Figure 32 TT Series Transceiver Typical Application Circuit with External Microprocessor In this example CO is high and C1 is low so S0 S3 are inputs and S4 S7 In this example CO is low and C1 is high so SO S8 are outputs and are outputs The inputs are connected to buttons that pull the lines high S4 S7 are inputs This is inverted from the circuit in Figure 31 making it the and weak pull down resistors to keep the lines from floating when the matching device buttons are not pressed The outputs would be connected to external application circuitry In this circuit the Command Data Interface is connected to a microcontroller for using some of the advanced features LATCH EN is low so the outputs are momentary The microcontroller controls the state of the ACK EN line it can receive The Command Data Interface is not used in this design so CMD DATA IN a command perform an action and then take the line high to send is tied high and CMD DATA OUT is not connected Acknowledgement packets This lets the user on the other end know that the action took place and not just that the command was rece
17. Techniques for Low Cost RF Data Links AN 00140 The FCC Road Part 15 from Concept to Approval AN 00500 Antennas Design Application Performance AN 00501 Understanding Antenna Specifications and Operation RG 00103 TT Series Transceiver Command Data Interface Reference Guide Figure 34 Helpful Application Note Titles Interference Considerations The RF spectrum is crowded and the potential for conflict with 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 produces noise and hashing on the output and reduces the link s overall range High level interference is caused by nearby products sharing the same frequency or from near
18. ate a status line toggles the output state If this line is low then the output lines are momentary active for as long as a valid signal is received Pull low to perform a soft reset of the module This line has an internal pull up to POWER DOWN May be left unconnected Received Signal Strength Indicator This line outputs an analog voltage that increases with the strength of the received signal It is updated once a second Power Down Pulling this line low places the module into a low power state The module is not functional in this state Pull high for normal operation Do not leave floating Supply Voltage Command Data In Input line for the serial interface commands Command Data Out Output line for the serial interface commands This line sets the input output direction for status lines SO S3 When low the lines are outputs when high they are inputs This line goes high when the module receives an acknowledgement message from another module after sending a control message This line sets the input output direction for status lines S4 S7 When low the lines are outputs when high they are inputs A high on this line initiates the Pair process which causes two units to accept each other s transmissions It is also used with a special sequence to reset the module to factory default configuration This line indicates module activity It can Source enough current to drive a small LED causing it to flash
19. 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 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 shorter useful distances for the link Pad Layout The pad layout diagram in Figure 35 is designed to facilitate both hand and automated assembly 0 050 0 050 0 028 1 27 1 27 0 71 le 9 965 EE EEREEEEEZELELBB B 1 65 i 0 605 15 37 0 04 EEREEAACUNCCRNNNEEUUNN pap Figure 35 Recommended PCB Layout Board Layout Guidelines The module s design makes integration straightforward however it is still critical to exercise care in PCB layout Failure to observe good layout techniques can result in a significant degradation of the module s performance A primary la
20. cessary for successful communication The TRM 900 TT radio transmitter has been approved by the FCC and Industry Canada to operate with the antenna types listed in Figure 30 with the maximum permissible gain and required antenna impedance for each antenna type indicated Antenna types not included in this list having a gain greater than the maximum gain indicated for that type are strictly prohibited for use with this device Conform ment la r glementation d Industrie Canada le pr sent metteur radio peut fonctionner avec une antenne d un type et d un gain maximal ou inf rieur approuv pour l metteur par Industrie Canada Dans le but de r duire les risques de brouillage radio lectrique l intention des autres utilisateurs il faut choisir le type d antenne et son gain de sorte que la puissance isotrope rayonn e quivalente p i r e ne d passe pas l intensit n cessaire l tablissement d une communication satisfaisante Le pr sent metteur radio TRM 900 TT a t approuv par Industrie Canada pour fonctionner avec les types d antenne num r s la Figure 30 et ayant un gain admissible maximal et l imp dance requise pour chaque type d antenne Les types d antenne non inclus dans cette liste ou dont le gain est sup rieur au gain maximal indiqu sont strictement interdits pour l exploitation de l metteur Antennas Antennes Linx Part Number Type Gain Impedance R f rence Linx Imp dance Test
21. device Furthermore extended operation at these maximum ratings may reduce the life of this device Figure 4 Absolute Maximum Ratings a Warning This product incorporates numerous static sensitive components Always wear an ESD wrist strap and observe proper ESD handling procedures when working with this device Failure to observe this precaution may result in module damage or failure TRM xxx TT Typical Performance Graphs 13 00 8 00 3 00 2 00 7 00 Output Power dBm 12 00 17 00 T T T T T 0 150 300 450 600 750 900 LVL ADJ Resistance kQ Figure 6 TT Series Transceiver Output Power vs LVL_ADJ Resistance 39 wo A N Supply Current mA m AR EF Ko 25 20 15 10 5 0 5 10 15 TX Output Power dBm Figure 7 TT Series Transceiver Peak Current Consumption vs Transmitter Output Power at 3 3V O Mw A N o N A Supply Current mA EF Ke 25 20 15 10 5 0 5 10 15 TX Output Power dBm Figure 8 TT Series Transceiver Peak Current Consumption vs Transmitter Output Power at 5 5V 24 Supply Current mA 25 20 15 10 5 0 5 10 15 TX Output Power dBm Figure 9 TT Series Transceiver Average Current Consumption vs Transmitter Output Power at 3 3V 85 C pum TT 6 o gt aet a o d E T ae se tu wp ae M B 7
22. econds or a sustained high input which can be used to extend the Search and successful pairing display With a momentary activation the search is terminated after 30 seconds If Pairing is started with a sustained high input the search continues as long as the PAIR input is high When Pair is activated the module displays the Pair Search sequence on the MODE IND line Figure 22 and goes into a search mode where it looks for another module that is also in search mode It alternates between transmit and receive enabling one unit to find the other and respond Once bidirectional communication is established the two units store each other s addresses in their Paired Module List with full Permissions Mask and display the Pair Found sequence on their MODE IND lines The Pair Found sequence is displayed for at least 3 seconds If the PAIR input is held high from the beginning of Pairing the Pair Found display is shown for as long as PAIR is high When Pairing is initiated the module pairs with the first unit it finds that is also in Pair Search If multiple systems are being Paired in the same area Such as in a production environment then steps should be taken to ensure that the correct units are paired with each other The Pair process can be canceled by taking PAIR high a second time If the address table is full when the PAIR line is raised the Pair Error sequence is displayed on the MODE IND line for 10 seconds and neither of the Pai
23. ed Antennas ANT 916 CW QW Ya Wave Whip 1 848Bi 500 ANT 916 CW HW 1 Wave Dipole Helical 1 830Bi 500 ANT 916 PW LP Ya Wave Whip 2 44dBi 500 ANT 916 SP 14 Wave Planar 1 350Bi 500 ANT 916 WRT RPS 1e Wave Dipole Helical 1 830Bi 500 ANT 916 CHP Ya Wave Ceramic 1 348Bi 500 Antennas of the same type and same or lesser gain ANT 916 CW HD Ya Wave Whip 0 260Bi 500 ANT 916 PW QW Ya Wave Whip 1 848Bi 500 ANT 916 CW RCL Ya Wave Whip 2 038Bi 500 ANT 916 CW RH Ya Wave Whip 1 310Bi 500 ANT 916 CW HWR RPS Y Wave Dipole Helical 1 890Bi 500 ANT 916 PML 1e Wave Dipole Helical 0 380Bi 500 ANT 916 PW RA Ya Wave Whip OdBi 500 ANT 916 USP Ya Wave Planar 0 3dBi 500 Cable Assemblies Assemblages de C bles Linx Part Number R f rence Linx CSI RSFB 300 UFFR RP SMA Bulkhead to U FL with 300mm cable CSI RSFE 300 UFFR RP SMA External Mount Bulkhead to U FL with 300mm cable Also available in 100mm and 200mm cable length Description Figure 30 TT Series Approved Antennas Typical Applications GND GND Figure 31 and Figure 32 show circuits using the TT Series transceiver NC ANTENNA GND GND enp lt GND GND NC NC NC ANTENNA 3 NC NC GND 4 GND GND GND GND NC NC NC NC NC so ACK_EN S1 MODE_IND NC GND GND ACK_EN s2 MODE_IND 11 s3 Ci GND GND lt GND GND 100k 12 m BA LVL_ADJ ACK_OUT 13 LATCH EN co vcc o S3 Ci GND lt p GND lt LVL_ADJ ACK_OUT R
24. eived to make a particular status line high it will remain high until a separate activation is received to make it go low The transmission must stop and the module must time out before it will register a second transmission and toggle the outputs When the LATCH EN line is high all of the outputs are latched A serial command is available to configure latching of individual lines E i The Power Down POWER DOWN line can be used to completely power 1 Power ES 1 Power B 1 down the transceiver module without the need for an external switch Power Ee Resistor Level dBm Resistor Level dBm Resistor This line allows easy control of the transceiver power state from external evel CEW Weie Value value components such as a microcontroller The module is not functional while 57 12 2 Open 38 3 4 154k 19 5 4 44 2k in power down mode 56 12 1 750k 37 amp 1 143k 18 57 41 2k AE 55 12 1 649k 36 2 7 133k 17 6 1 37 4k Warning Pulling any of the module inputs high while in Power Down 54 11 8 576k 35 2i 127k 16 67 34 8k can partially activate the module increasing current consumption and potentially placing it into an indeterminate state that could lead oe MES 9108 95 Im TER da ES se ak to unpredictable operation Pull all inputs low before pulling POWER_ 22 ga qp e ti TK ime J edem AAK DOWN low to prevent this issue Lines that may be hardwired for 51 9 7 412k 32 0 8 105k 13 7 9 26 7k example the ACK_EN l
25. eiver incorporates a precision Vee TO low dropout regulator which allows operation MODULE over a wide input voltage range Despite this regulator it is still important to provide a supply Vcc IN that is free of noise Power supply noise can significantly affect the module s performance so le providing a clean power supply for the module should be a high priority during design 10Q 10 F Figure 27 Supply Filter A 100 resistor in series with the supply followed by a 10uF tantalum capacitor from V to ground helps in cases where the quality of supply power is poor Figure 27 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 The Command Data Interface The TT Series transceiver has a serial Command Data Interface CDI that offers the option to configure and control the transceiver through software instead of through hardware This interface consists of a standard UART with a serial command set This allows for fewer connections in applications controlled by a microcontroller as well as for more control and advanced features than can be offered through hardware pins alone The serial port uses the CMD_DATA_IN and CMD_DATA_OUT lines as a UART An automatic baud rate detection system allows the interface to run at a variable data rate from 9 6kbps to 57 6kbps The Command Data Interface has two sets of operators One is a set
26. ented are more subject to interference This module does have a frequency hopping protocol built in but the developer should still be aware of the risk of interference Do not use any Linx product over the limits in this data guide Excessive voltage or extended operation at the maximum voltage could cause product failure Exceeding the reflow temperature profile could cause product failure which is not immediately evident Do not make any physical or electrical modifications to any Linx product This will void the warranty and regulatory and UL certifications and may cause product failure which is not immediately evident ao A N N a a 12 14 15 16 18 19 19 20 21 21 22 22 23 23 24 24 26 27 28 31 32 Table of Contents Description Features Ordering Information Electrical Specifications Absolute Maximum Ratings Transceiver Timings TRM xxx TT Typical Performance Graphs Pin Assignments Pin Descriptions Theory of Operation Module Description Basic Hardware Operation Transceiver Operation Transmit Operation Receive Operation The Pair Process Permissions Mask Acknowledgement Mode Indicator Reset to Factory Default Using the RSSI Line Using the LATCH EN Line Using the Low Power Features Using the LVL_ADJ Line Receiver Duty Cycle Power Supply Requirements The Command Data Interface Frequency Hopping Usage Guidelines for FCC Compliance 32 33 34 34 34 36 38 39 40 41 41 43 44
27. features and functionality This guide focuses on hardware operation with some references to software operation Please see Reference Guide RG 00103 the TT Series Command Data Interface for details on software operation The module has 8 status lines numbered SO through S7 These can be set as inputs for buttons or contacts or as outputs to drive application circuitry When SO is taken high on one module SO goes high on the receiving module and so forth A line that is an input on one side needs to be set as an output on the other side Since this module can act as both transmitter and receiver terminology and descriptions are important This guide uses the term Initiating Unit IU to describe a module that is transmitting commands Responding Unit RU is used to describe a module that is receiving commands The transceiver uses a Frequency Hopping Spread Spectrum FHSS algorithm This allows for higher output power and longer range than narrow band systems while still maintaining regulatory compliance All aspects of managing the FHSS operations are automatically handled by the module The TT Series has received modular certification for the FCC in the United States and Industry Canada when used with an approved antenna The module may be placed in an end product without further transmitter testing though unintentional radiator testing may be required Please see the Usage Guidelines for FCC Compliance section for more details 15
28. ge proportional to the incoming signal strength The RSSI Voltage vs Input Power graph in the Typical Performance Graphs section shows the relationship between the RSSI voltage and the incoming signal power This line has a high impedance so an external buffer may be required for some applications The RSSI line updates once a second showing either the strength of the packet received within the last second or the current channel measurement The formula to convert the RSSI voltage to power in dBm is Pay Vasa Vog 60 105 Note The RSSI levels and dynamic range vary from part to part It is also important to remember that the RSSI output indicates the strength of any in band RF energy and not necessarily just that from the intended transmitter therefore it should be used only to qualify the presence and level of a signal Using RSSI to determine distance or data validity is not recommended The RSSI output can be utilized during testing or even as a product feature to assess interference and channel quality by looking at the RSSI level with all intended transmitters shut off Using the LATCH EN Line The LATCH EN line sets the outputs to either momentary operation or latched operation During momentary operation the outputs go high for as long as control messages are received instructing the module to take the lines high As soon as the control messages stop the outputs go low During latched operation when a signal is rec
29. hen a valid control packet is received the module sends back a simple acknowledgement ACK It sends an Acknowledge with Data AWD response when custom data is programmed into the module using a serial command Transmit Operation Transmit Operation is entered when any of the status line inputs go high During Transmit Operation the MODE IND line is high The module repeatedly transmits control messages containing the local address and the state of all status lines Between transmissions the module listens for acknowledgement messages If an Acknowledge ACK or Acknowledge with Data AWD message is received for the transmitted data the ACK OUT line is asserted for 100ms The ACK OUT timing restarts on each ACK or AWD packet that is received The transceiver sends control messages every 12 5ms as long as any of the status line inputs is high updating the status line states with each packet When all input lines are low the module starts the shutoff sequence During the shutoff sequence the transmitter sends at least one packet with all outputs off It then continues to transmit data until the current channel hopping cycle is complete resulting in balanced channel use If an input line is asserted during the shutoff sequence the transmitter cancels the shutoff and extends the transmission sequence Receive Operation During Receive Operation the module waits for a valid control message from an authorized paired transceiver When
30. hip style antenna Figure 44 provides outstanding overall performance and stability A low cost whip 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 ul connectorized mounting styles Figure 44 Whip Style Antennas The wavelength of the operational frequency determines an antenna s overall length Since a full wavelength fast is often quite long a partial Y2 or 4 wave antenna F MHz is normally employed Its size and natural radiation Figure 45 L length in feet of resistance make it well matched to Linx modules quarter wave length The proper length for a straight 4 wave can be easily r operating frequency determined using the formula in Figure 45 It is also in megahertz 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 Figure 46 Many of these styles utilize helical elements to reduce the overall antenna size while maintaining reasonable performance A helical antenna s bandwidth is ofte
31. ile memory Program a new value to non volatile memory Set all configuration items to their factory default values Erase all paired addresses from memory Transmit a control message Transmit an acknowledgement for received data Transmit an Acknowledge With Data AWD response with two bytes of custom data Description NULL terminated string of up to 16 characters that identifies the module Read only 3 byte firmware version Read only 4 byte factory set serial number Read only The module s 32 bit local address Status lines direction 1 Inputs O Outputs LSB SO used when enabled by Control Source Latching enable for output lines LSB SO used when enabled by Control Source TX output power signed nominal dBm used when enabled by Control Source Configures the control options Select message types to capture for serial readout Sets the index number address and permissions mask of paired modules Receiver duty cycle control Read the current state of the status and control lines Read the RSSI of the last packet received and ambient level Read only Read the voltage on the L VL ADJ line Read only Read the operating status of the module Read the last received packet Read only Sets the mask for events to generate a break on CMD DATA OUT Event flags that are used with the Interrupt Mask re 28 TT Series Transceiver Command Data Interface Commands and Parameters Frequency Ho
32. ine can be connected to the POWER_DOWN 50 8 9 347k 31 0 3 97 6k 12 8 3 24 3k line so that they are lowered when POWER_DOWN is lowered 49 8 3 340k 30 0 1 91k 11 8 8 22k 48 8 0 316k 29 0 6 86 6k 10 9 3 19 6k Using the LVL_ADJ Line 47 74 287k 28 0 9 80 6k 9 9 1 17 4k The Level Adjust LVL_ADJ line allows the transceiver s output power to be 46 6 9 267k 27 14 76 8k 8 9 6 15 4k easily adjusted for range control or lower power consumption This is done 45 6 7 243k 06 1 18 715 7 102 13 3k by placing a resistor to ground on LVL_ADJ to form a voltage divider with 44 63 226k 25 93 665k 6 208 143k an internal 100kQ resistor When the transceiver powers up the voltage on 43 5 8 210k o ET 62k E 2415 95 this line is measured and the output power level is set accordingly When 42 5 3 200k 23 3 2 57 6k 4 12 2 7 5k LVL ADJ is connected to V or floating the output power and current 41 4 8 182k 22 3 7 54 9k 3 13 0 5 76k consumption are the highest When connected to ground the output power and current are the lowest The power is digitally controlled in 58 ES Wess 2 ps pus 2 OS steps providing approximately 0 5dB per step See the Typical Performance 39 4 0 165k 20 48 47k 1 145 2 32k Graphs section Figure 6 for a graph of the output power vs L VL ADJ 0 15 7 750 resistance Figure 23 Power Level vs Resistor Value Warning The LVL ADJ line uses a resistor divider to create a voltage that determines the output
33. inting 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 Final compliance testing is 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 the completed product has passed an ID number is issued that is to be clearly placed on each product manufactured Questions regarding interpretations of the Part 2 and Part 15 rules or the 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 Equipment Authorization Division Customer Service Branch MS 1300F2 7435 Oakland Mills Road Columbia MD US 21046 Phone 1 301 725 585 Fax 1 301 344 2050 Email labinfo fcc gov ETSI Secretaria 650 Route des Lucioles 06921 Sophia Antipolis Cedex FRANCE Phone 433 0 4 92 94 42 00 Fax 33 0 4 93 65 47 16 International approvals are slightly more complex although Linx modules are desig
34. ived ACK_OUT and MODE IND are connected to LEDs to provide visual indication to the user PAIR is connected to a button and pull down resistor to initiate the Pair Process when the button is pressed ACK EN is tied high so the module sends acknowledgements as soon as it receives a control message 96 37 Antenna Considerations The choice of antennas is a critical and often overlooked Q design consideration The range N 9 performance and legality of an RF x pun Pt n link are critically dependent upon the AN Ji antenna While adequate antenna SOS performance can often be obtained by trial and error methods antenna design and matching is acomplex Figure 33 Linx Antennas task Professionally designed antennas such as those from Linx Figure 33 help ensure maximum performance and FCC and other regulatory compliance Linx transmitter modules typically have an output power that is 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 L VL ADJ line 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
35. late may be used to maximize the antenna s performance 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 In some applications it is advantageous to place the module and antenna away from the main equipment Figure 43 This can avoid interference problems and allows the antenna to be oriented for optimum performance Always use 500 coax like RG 174 for the remote feed CASE aa GROUND PLANE NUT MAY BE NEEDED Figure 43 Remote Ground Plane 47 Common Antenna Styles There are 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 AN 00500 and AN 00501 Linx antennas and connectors offer outstanding performance at a low price A w
36. may be utilized and the corresponding sacrifice in performance accepted OPTIMUM USABLE NOT RECOMMENDED Figure 41 Ground Plane Orientation 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 In many antenna designs particularly wave whips the ground plane acts as a counterpoise forming in essence VERTICAL 144 GROUNDED a Ye wave dipole Figure 42 For this reason ANTENNA MARCONI 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 less than or equal to the overall length of the 74 wave radiating element This is often not practical due to Pros A DIPOLE ELEMENT M4 GROUND size and configuration constraints In these PLANE n i VIRTUAL 2 4 instances a designer must make the best use DIPOLE of the area available to create as much ground Figure 42 Dipole Antenna 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 p
37. module s average current consumption can be calculated with the following equation Ton x Inx Tsay x IsBv lava DCycle Figure 25 Receiver Duty Cycle Average Current Consumption Equation Ton S fixed at about 0 326 seconds and T current lp and standby current typical values are in Figure 26 TT Series Typical Current Consumption 2 5 3 0 3 3 3 5 4 0 4 5 5 0 5 5 sgy DCycle T The receiver spy Vary with supply voltage but some Voc VDC lo 16 5 17 8 18 7 18 8 18 8 18 9 18 9 18 9 mA i 0 0862 0 1471 0 1509 0 1525 0 1569 0 1616 0 1669 0 1737 Figure 26 TT Series Transceiver Typical Current Consumption Figure 15 shows a graph of the average current consumption vs duty cycle for several supply voltages This graph shows that the average current consumption can be significantly reduced with even a small duty cycle value This is ideal for battery powered applications that need infrequent updates or where response time is not critical The KeepOn time is used to keep the receiver on after it has completed some activity This activity includes completing a transmission and receiving a valid packet After KeepOn seconds have elapsed with no transmit or valid receive activity the module goes into standby for DCycle seconds Please see Reference Guide RG 001 039 the TT Series Command Data Interface for details on configuring the receiver duty cycle Power Supply Requirements The transc
38. n quite narrow and the antenna can detune in proximity to other objects so o Specialty Style care must be exercised in layout and placement A RR eee ree A loop or trace style antenna is normally printed directly on a product s PCB Figure 47 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 VSWR at the desired frequency which can cause instability in the RF stage Figure 47 Loop or Trace Antenna Linx offers low cost planar Figure 48 and chip antennas that mount directly to a product s PCB These tiny antennas do not require testing and provide excellent performance despite their small Size They offer a preferable alternative to the often problematic printed antenna Figure 48 SP Series Splatch and uSP MicroSplatch Antennas ps SIC rm Mera AW7 3 rien REDE Regulatory Considerations Note Linx RF modules are designed as component devices that require external
39. nds an Acknowledgement Packet If the Initiating Unit IU receives an Acknowledgement Packet that has the same Address and Status Byte as in the Control Packet it originally sent then it pulls the ACK OUT line high A continuous stream of Control Packets that triggers a continuous stream of Acknowledgement Packets keeps the ACK OUT line high Connecting the ACK EN line to V causes the RU to transmit Acknowledgement Packets as soon as it receives a valid Control Packet Alternately this line can be controlled by an external circuit that raises the line when a specific action has taken place This confirms to the IU that the action took place and not just acknowledges receipt of the signal Mode Indicator The Mode Indicator line MODE IND provides feedback about the current state of the module This line switches at different rates depending on the module s current operation When an LED is connected to this line it blinks providing a visual indication to the user Figure 22 gives the definitions of the MODE IND timings MODE_IND Timing Module Status Display Transmit Mode Solid ON when transmitting packets Receive Mode Solid ON when receiving packets Pair Search ON for 100ms OFF for 900ms while searching for another unit during the Pair process ON for 400ms OFF for 100ms when the transceiver has been Pair Found Paired with another transceiver This is displayed for at least 3 seconds Pair Error ON for 100ms OFF for 10
40. ne is essential for creating a low impedance return for ground and consistent stripline performance Use care in routing the RF trace between the module and the antenna or connector Keep the trace as short as possible Do not pass it under the module or any other component Do not route the antenna trace on multiple PCB layers as vias add inductance Vias are acceptable for tying together ground layers and component grounds and should be used in multiples Each of the module s ground pins should have short traces tying immediately to the ground plane through a via Bypass caps should be low ESR ceramic types and located directly adjacent to the pin they are serving A 50 ohm coax should be used for connection to an external antenna A 50 ohm transmission line such as a microstrip stripline or coplanar waveguide should be used for routing RF on the PCB The Microstrip Details section provides additional information In some instances a designer may wish to encapsulate or pot the product There are a wide variety of potting compounds with varying dielectric properties Since such compounds can considerably impact HF performance and the ability to rework or service the product it is the responsibility of the designer to evaluate and qualify the impact and suitability of such materials 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 fac
41. ned to allow all international standards to be met If the end product is to be exported to other countries contact Linx to determine the specific suitability of the module to the 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 51 Linx TECHNOLOGIES Linx Technologies 159 Ort Lane Merlin OR US 97532 Phone 1 541 471 6256 Fax 1 541 471 6251 www linxtechnologies com Disclaimer 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 Data 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 i
42. odule 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 ca 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 45 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 Optimum performance is obtained from a or e wave straight whip mounted at a right angle to the ground plane Figure 41 In many cases this isn t desirable for practical or ergonomic reasons thus an alternative antenna style such as a helical loop or patch
43. or indication to a user The Command Data Interface section describes the more advanced features that are available with the serial interface GND ANTENNA GND vcc o GND 4 100k NC pen vocho 100k so ACK_EN it vcc o 1 GND GND 100k S2 vocho oO 3 MODE_IND C1 GND 4 GND 4 LVL ADJ ACK OUT 91k 196 LATCH EN co RESET CMD_DATA_OUT GND GND S7 CMD DATA IN S6 S4 S5 vcc POWER DOWN TRM XXX TT GND lt H 4 GND GND 96 _jvco 35 3 eno 33 22 lvcc 31 GND E o vcc 100k GND 2 PL gt eno 29 128 gt GND 27 vcc 4 ne ANTENNA GND 24 and GND ne NC 4 ne NC GND 4 and GND Z Nc NC PE 4 ne Nc HZ so ACK_EN cst PH si MODE IND GND lt 4 and GND GF se PAIR css 344 ss c1 GND 4 4 LVL ADI ACK_OUT 91k 1 cc H LATCH EN co 161 RESET CMD_DATA_OUT GND GND s7 CMD_DATA_IN s6 s5 s4 vec lt RSSI POWER DOWN GND GND TRM XXX TT gt GND Figure 21 TT Series Transceiver Basic Application Circuits for Bi directional Remote Control 17 Transceiver Operation The transceiver has two modes of operation Initiating Unit IU that transmits control messages and Responding Unit RU that receives control messages If all of the status lines are set as inputs then the module is set as an IU only The module stays in a low power sleep mode until a status line goes high starting the Transmit Ope
44. or remove the module from the end product Note The integrator is required to perform unintentional radiator testing on the final product per FCC sections 15 107 and 15 109 and IC RSS GEN Any changes or modifications not expressly approved by Linx Technologies could void the user s authority to operate the equipment Additional Testing Requirements The modules have been tested for compliance as an intentional radiator but the integrator is required to perform unintentional radiator testing on the final product per FCC sections 15 107 and 15 109 and Industry Canada license exempt RSS standards Additional product specific testing might be required Please contact the FCC or Industry Canada regarding regulatory requirements for the application Ultimately is it the integrator s responsibility to show that their product complies with the regulations applicable to their product Information to the user The following information must be included in the product s user manual FCC IC NOTICES This product contains FCC ID OJMTRM9OOTTA IC 5840A TRM900TTA This device complies with Part 15 of the FCC rules and Industry Canada license exempt RSS standards Operation of this device is subject to the following two conditions 1 This device may not cause harmful interference and 2 this device must accept any interference received including interference that may cause undesired operation This equipment has been tested and found
45. power which results in longer range and better performance within that range Since the transmission is moving among multiple channels interference on one channel causes loss on that channel but does not corrupt the entire link This improves the reliability of the system Usage Guidelines for FCC Compliance The TT Series module is provided with an FCC and Industry Canada Modular Certification This certification shows that the module meets the requirements of FCC Part 15 and Industry Canada license exempt RSS standards for an intentional radiator The integrator does not need to conduct any further testing under these rules provided that the following guidelines are met e An approved antenna must be directly coupled to the module s U FL connector through an approved coaxial extension cable e Alternate antennas can be used but may require the integrator to perform certification testing e The module must not be modified in any way Coupling of external circuitry must not bypass the provided connectors e End product must be externally labeled with Contains FCC ID OJMTRM9OOTTA IC 5840A TRM9OOTTA e The end product s user s manual must contain an FCC statement equivalent to that listed on page 33 of this data guide e The antenna used for this transceiver must not be co located or operating in conjunction with any other antenna or transmitter e The integrator must not provide any information to the end user on how to install
46. power and achieves a range of over 2 miles 3 2 kilometers line of site in typical environments with OdB gain antennas A high power version outputs 23 5dBm achieving up to 8 miles 12 8km Primary settings are hardware selectable which eliminates the need for an external microcontroller or other digital interface For advanced features optional software configuration is provided by a UART interface however no programming is required for basic operation Housed in a compact reflow compatible SMD package the transceiver requires no external RF components except an antenna Features e FCC and Canada pre certified e 8 status lines 2 byte data input e 2 mile 3 2km or 8 mile 12 8km Bi directional remote control line of sight range e Selectable acknowledgements e Highly efficient power use e 2 possible addresses e Programmable receiver duty cycle e Serial interface for optional e No programming tuning required software operation cd Revised 3 18 2015 Ordering Information Ordering Information Figure 2 Ordering Information Electrical Specifications TT Series Transceiver Specifications ESTI my Tessa d d m e Wem 82 9 m 44 WaesssEm O w m 2 Treo T mw Ara Psp Came monza H mA M Tess TD m TkSewOwm i 585 59 mA M2 CCT My aA M pomor Don Curent tm G1 aA Ma TT Series Transcei
47. pping The module incorporates a Frequency Hopping Spread Spectrum FHSS algorithm This provides immunity from narrow band interference as well as meets regulatory requirements for higher output power resulting in longer range The module uses 25 HF channels as shown in Figure 29 Channel Frequencies Channel Frequency Channel Frequency Channel Frequency Number Number Number 1 902 62 10 907 12 18 911 12 2 903 12 11 907 62 19 911 62 3 903 62 12 908 12 20 912 12 4 904 12 13 908 62 21 912 62 5 904 62 14 909 12 22 913 12 6 905 12 18 909 62 23 913 62 7 905 62 16 910 12 24 914 12 8 906 12 We 910 62 25 914 62 9 906 62 Figure 29 TT Series Transceiver RF Channel Frequencies Each channel has a time slot of 12 5ms before the module hops to the next channel This equal spacing allows a receiver to hop to the next channel at the correct time even if a packet is missed Up to seven consecutive packets can be missed without losing synchronization The hopping pattern is determined from the transmitter s address Each sequence uses all 25 channels but in different orders Once a transmission starts the module continues through a complete cycle If the input line is taken low in the middle of a cycle the module continues transmitting through the end of the cycle to ensure balanced use of all channels Frequency hopping has several advantages over single channel operation Hopping systems are allowed a higher transmitter output
48. quality and settling time The transmitter output power is programmable from 15 5dBm to 12 5dBm with automatic PA ramping to meet transient spurious specifications The ramping and frequency deviation are optimized to deliver the highest performance over a wide range of data rates The receiver incorporates highly efficient low noise amplifiers that provide up to 112dBm sensitivity Advanced interference blocking makes the transceiver extremely robust when in the presence of interference A low power onboard communications processor performs the radio control and management functions A control processor performs the higher level functions and controls the serial and hardware interfaces This block also includes voltage translation to allow the internal circuits to operate at a low voltage to conserve power while enabling the interface to operate over the full external voltage This prevents hardware damage and communication errors due to voltage level differences While operation is recommended from 3 3V to 5 0V the transceiver can operate down to 2 5V 14 Module Description The TT Series remote control and sensor transceiver module is a completely integrated RF transceiver and processor It has two main modes of operation hardware and software Hardware operation is basic and is suitable for applications like keyfobs where no other processor PC or interface is present Software operation is more advanced and allows for more
49. ration If all of the status lines are set as outputs then the module is set as an RU only It stays in Receive Operation looking for a valid transmission from a paired IU A module with both input and output status lines can operate as an IU and an RU The module idles in Receive Operation until either a valid transmission is received or a status line input goes high initiating the Transmit operation When an input goes high the transceiver captures the logic state of each of the status lines The line states are placed into a packet along with the local 32 bit address The IU transmits the packets as it hops among 25 RF channels An RU receives the packet and checks its Paired Module List to see if the IU has been paired with the module and is authorized to control it If the IU s address is not in the table then the RU ignores the transmission If the address is in the table then the RU calculates the channel hopping pattern from the IU s address and sets its status line outputs according to the received packet It then hops along with the IU and updates the states of its outputs with every packet Its outputs can be connected to external circuitry that activates when the lines go high The RU can also send an acknowledgement back to the IU Using the Serial interface the RU can include up to two bytes of custom data with the acknowledgement such as sensor data or battery voltage levels Using the hardware control if ACK EN is high w
50. ree alloys Reflow Oven 255 C max see Figure 40 Figure 39 Absolute Maximum Solder Times Automated Assembly For high volume assembly the modules are generally auto placed The modules have been designed to maintain compatibility with reflow processing techniques however due to 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 44 Reflow Temperature Profile see The single most critical stage in the automated assembly process is the reflow stage The reflow profile in Figure 40 should not be exceeded because excessive temperatures or transport times during reflow will irreparably damage the modules Assembly personnel 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 300 Recommended RoHS Profile Recommended Non RoHS Profile q Max RoHS Profile 2507 2007 Temperature C 0 30 60 90 120 150 180 210 240 270 300 330 360 Time Seconds Figure 40 Maximum Reflow Temperature Profile Shock During Reflow Transport sess Since some internal m
51. ring units will store an address In this case the module should either be reset to clear the address table or the serial interface can be used to remove addresses If a paired unit is already in the Paired Module List then no additional entry is added though the existing entry s Permissions Mask may be modified Permissions Mask The TT Series Transceiver has a Permissions Mask that is used to control which lines an IU is authorized to control With most systems if a transmitter is associated with a receiver then it has full control over the receiver With the Permissions Mask a transmitter can be granted authority to control only certain receiver outputs If an IU does not have the authority to activate a certain line then the RU does not set it As an example a factory worker can be given a fob that only opens the door to the factory floor while the CEO has a fob that can also open the executive offices The hardware in the fobs is the same but the permissions masks are set differently for each fob The Pair process always sets the Permission Mask to full access The mask can be changed through the serial interface Acknowledgement A responding module is able to send an acknowledgement to the transmitting module This allows the initiating module to know that the responding side received the command When the Responding Unit RU receives a valid Control Packet it checks the state of the ACK EN line If it is high the module se
52. rising 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 2015 Linx Technologies All rights reserved The stylized Linx logo Wireless Made Simple WiSE CipherLinx and the stylized CL logo are trademarks of Linx Technologies
53. romettre le fonctionnement Product Labeling The end product must be labeled to meet the FCC and IC product label requirements It must have the below or similar text Contains FCC ID OJMTRM9OOTTA IC 5840A TRM900TTA The label must be permanently affixed to the product and readily visible to the user Permanently affixed means that the label is etched engraved stamped silkscreened indelibly printed or otherwise permanently marked on a permanently attached part of the equipment or on a nameplate of metal plastic or other material fastened to the equipment by welding riveting or a permanent adhesive The label must be designed to last the expected lifetime of the equipment in the environment in which the equipment may be operated and must not be readily detachable FCC RF Exposure Statement To satisfy RF exposure requirements this device and its antenna must operate with a separation distance of at least 20cm from all persons and must not be co located or operating in conjunction with any other antenna or transmitter Antenna Selection Under FCC and Industry Canada regulations this radio transmitter may only operate using an antenna of a type and maximum or lesser gain approved for the transmitter by the FCC and Industry Canada To reduce potential radio interference to other users the antenna type and its gain should be so chosen that the equivalent isotropically radiated power e i r p is not more than that ne
54. s 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 a
55. to comply with the limits for a Class B digital device pursuant to Part 15 of the FCC Rules These limits are designed to provide reasonable protection against harmful interference in a residential installation This equipment generates uses and can radiate radio frequency energy and if not installed and used in accordance with the instructions may cause harmful interference to radio communications However there is no guarantee that interference will not occur in a particular installation If this equipment does cause harmful interference to radio or television reception which can be determined by turning the equipment off and on the user is encouraged to try to correct the interference by one or more of the following measures e Reorient or relocate the receiving antenna e Increase the separation between the equipment and receiver e Connect the equipment into an outlet on a circuit different from that to which the receiver is connected e Consult the dealer or an experienced radio TV technician for help Any modifications could void the user s authority to operate the equipment Le pr sent appareil est conforme aux CNR d Industrie Canada applicables aux appareils radio exempts de licence L exploitation est autoris e aux deux conditions suivantes 1 l appareil ne doit pas produire de brouillage et 2 utilisateur de l appareil doit accepter tout brouillage radio lectrique subi m me si le brouillage est susceptible d en comp
56. tor 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 and 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 0 062 in 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 in Figure 36 and examples are provided in Figure 37 Software for calculating microstrip lines is also available on the Linx website Ground plane E 73 2 i i2d7W CNN CLA we eu V E W 4d gt ae Zo 2 w iy For gt 1 wW w d VEe E 1 393 0 667 Y 1444 E Dielectric constant of PCB material Figure 36 Microstrip Formulas Example Microstrip Calculations Width Height Effective Dielectric Characteristic o on Ratio W d Constant Impedance 0 4 80 1 8 3 59 50 0 4 00 2 0 3 07 51
57. ver Specifications Operating Frequency Band f we os me a NunberotGremnes 5 5 remessa OO o CA A ds o e Spas emissions Perrocisao Recever Sensthty moan m s ASS Dye Parga amp e omae T Dmwear O ers fam e Ommna dm 6 Output Power Control 28 Range MamonoEmedos P Perroon WEmexe l RI 59 n Ommmowm R 49 es 9 Sorgo emo Rango 5 eem Moase tuwone TT Www a we 48 V MePONERDONN 80 ome an vese e ma serar commana nesens __ ResyReeEmeme 99 5 vito amr 9 m 8 _ TI O 8 we 9 IUoRUSmeHh 9 me chennalDwelTine 335 ms Twa X ago woo E v vos MS OC Transceiver Timings TT Series Transceiver Specifications Parameter Symbol Min Typ Max Units Notes TX Vcc SA Von Input i i TX Sx i l Logic Low Vie 0 8 VDC 9 i Logic Low Vin Vs 0 15 VDC 10 TX MODE IND poem l Logic High Vo 2 5 5 9 i i Logic High Vi Vo 0 25 0 8 45 VDC 10 RX Sx Output i 3 E RX MODE IND Logic Low Ne 0 6 VDC 1 i r n I Logic High Von Voc 0 7 Vos VDC 2 A B CDE F G H Certifications Modular Certifications FCG Industry Canada TT Series Transceiver Timings
58. yout goal is to maintain a characteristic 50 ohm impedance throughout the path from the antenna to the module Grounding filtering decoupling routing and PCB stack up are also important considerations for any RF design The following section provides some basic design guidelines During prototyping the module should be soldered to a properly laid out circuit board The use of prototyping or perf boards results in poor performance and is strongly discouraged Likewise the use of sockets can have a negative impact on the performance of the module and is discouraged 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 When possible separate RF and digital circuits into different PCB regions Make sure internal wiring is routed away from the module and antenna and is secured to prevent displacement 41 Do not route PCB traces directly under the module There should not be any copper or traces under the module on the same layer as the module just bare PCB The underside of the module has traces and vias that could short or couple to traces on the product s circuit board The Pad Layout section shows a typical PCB footprint for the module A ground plane as large and uninterrupted as possible should be placed on a lower layer of your PC board opposite the module This pla
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