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High Performance LF Remote Antenna Radio Frequency Module RI-RFM-008B   

 

 December 

1999 

1

 

 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 

Series 2000 Reader System

High Performance Remote Antenna-Reader Frequency Module

RI-RFM-008B

Antenna Tuning Board

RI-ACC-008B

Reference Guide

11-06-21-047  February 2002 

Summary of Contents for 2000 series

Page 1: ...Antenna Radio Frequency Module RI RFM 008B December 1999 1 Series 2000 Reader System High Performance Remote Antenna Reader Frequency Module RI RFM 008B Antenna Tuning Board RI ACC 008B Reference Guide 11 06 21 047 February 2002 ...

Page 2: ...d is not responsible for customer applications or product or software design or performance relating to systems or applications incorporating TI products In addition TI assumes no liability and is not responsible for infringement of patents and or any other intellectual or industrial property rights of third parties which may result from assistance provided by TI TI products are not designed inten...

Page 3: ...er Supply Requirements 28 3 2 Power Supply Connection 29 Chapter 4 Associated Antenna Systems 31 4 1 Antenna Requirements 32 4 2 Antenna Resonance Tuning 33 4 3 Tuning Procedure 34 Chapter 5 Regulatory Safety Warranty Notices 37 5 1 Regulatory Notes 38 5 1 1 FCC Notices U S A 38 5 1 2 CE Conformity Europe 38 Appendices Appendix 1 Field Strength Adjustment 39 Appendix 2 Adjustment of Oscillator Sig...

Page 4: ...uning Range Settings 35 Table 16 Oscillator Signal Pulse Width versus Resistor Value estimated values 41 Table 17 Maximum Distances between Antennas 46 Table 18 Characteristics of Radiated and Conducted Noise 49 Figure Locations Figure 1 RA RFM System 9 Figure 2 RFM Block Schematic 10 Figure 3 Pulse Width Examples 11 Figure 4 RA RFM Top View 13 Figure 5 RA RFM Bottom View 14 Figure 6 Antenna Tunin...

Page 5: ...RTAIN PROCEDURE MUST BE FOLLOWED IN ORDER TO PREVENT INJURY OR HARM TO YOUR HEALTH CAUTION This indicates information on conditions which must be met or a procedure which must be followed which if not heeded could cause permanent damage to the RA RFM Note Indicates conditions which must be met or procedures which must be followed to ensure proper functioning of the RA RFM Preface ...

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Page 7: ...ing the transmitter and receiver sections and placement of key user accessible components Topic Page 1 1 RA RFM Module General 8 1 2 Transmitter 10 1 3 Receiver 11 1 4 RA RFM Connections and Jumpers 11 1 5 Tuning Module General 16 1 6 Tuning Module Connectors and Jumpers 17 Chapter 1 ...

Page 8: ... HARMFUL TO YOUR HEALTH CAUTION This product may be subject to damage by electrostatic discharge ESD It should be handled by ESD protected personnel at ESD secured workplaces only The transmitter power output stage can only operate with a limited duty cycle Please pay attention to this whilst performing antenna tuning procedures Ground pins GND and GNDP must be connected externally to avoid damage...

Page 9: ...ssociated Antenna Tuning Board allows the use of up to 120 meters of symmetrically shielded antenna cable Twin Ax between an antenna and the Reader unit A system diagram is shown in Figure 1 Figure 1 RA RFM System ANTENNA LOOP ANTENNA TUNING BOARD TWIN AX CABLE RA RFM ...

Page 10: ...necessary programming and addressing signals to Read Write and Multipage transponders The data input and output lines which are connected to a data processing unit are low power Schottky TTL and HCMOS logic compatible The functions of the RA RFM are described in the following section PWM TX Oscillator RX Demodulator RXSS Interface RX Amplifier RXSS Threshold ATI Int TX Power Stage CPS TXCT RXDT RX...

Page 11: ... details refer to Section 2 Specifications Note The RA RFM has an in built temperature protection circuit which sharply limits the transmitter power stage output if an over current situation or an over temperature environment causes the temperature to exceed the allowed limits After the device is switched off and has time to recover when the temperature drops again or the over current situation is...

Page 12: ...iver The signal RXCK is the reference clock signal to decode the RXDT data stream The RXCK signal changes from low to high level during each data bit and the RXDT signal is valid before and after this positive slope for a certain time window For more details refer to Table 11 Timing Characteristics The receiver has a built in RF receive signal detector The receive signal strength is indicated by t...

Page 13: ...R409 RXSS noise level adjustment potentiometer SW1 Default all on Pos 1 CPS see Appendix 4 A 3 pin antenna connector connects the RA RFM via a symmetrically shielded antenna cable Twin Ax to the Antenna Tuning Board The RA RFM is normally mounted from the underside utilizing appropriate spacers and four M3 mounting bolts The top view of the RA RFM without the normally fitted heatsink is shown in F...

Page 14: ...5 The connectors J1 J2 and J4 are accessible from the underside J1 is the 16 pin module connector this carries the supply voltage lines the data and the control lines Figure 5 RA RFM Bottom View 5 3 1 3 1 1 3 5 7 9 11 13 15 6 4 2 4 2 2 4 6 8 10 12 14 16 J1 J2 J4 ANT_1 ANT_2 GNDA only available from top ...

Page 15: ...wer stage 12 CPS_OUT OUT Carrier Phase Synchronization oscillator signal output 13 VSP IN Supply voltage for transmitter power stage 14 RXSS OUT Receiver signal strength output active low 15 No connection 16 CPS_IN IN Carrier Phase Synchronization oscillator signal input CAUTION The transmitter ground pins GNDP and logic ground pin GND must be connected together externally The RA RFM may be otherw...

Page 16: ...in 4 GND Logic ground Table 4 lists the functions for the antenna connector used to connect the RA RFM to the Antenna Tuning Board Table 4 Connector ANT1 Pin Signal Direction Description 1 GNDA OUT Ground for cable shield 2 ANT_2 IN OUT Symmetrical antenna input output 2 3 ANT_1 IN OUT Symmetrical antenna input output 1 Jumper JP4 allows enabling and disabling of common noise filtering for EMI pur...

Page 17: ... and C8 on the Antenna Tuning Board The high resonance voltage and current flow through the resonator necessitate connecting these capacitors both in serial and parallel Each resonance capacitor can be switched in and out of circuit by a single jumper in order to tune the RFM to resonance i e match the RFM to different antenna inductances CAUTION If only one capacitor is switched parallel to the r...

Page 18: ...OUT Symmetric antenna signal from to RFM 3 GND IN Cable shield to housing ground Table 7 Tuning Capacitor Jumpers Capacitance nF Max Resonance Voltage peak peak VRF_max Description JP1 33 560 Capacitor C2 JP2 16 5 800 Capacitor C1 C2 in series JP3 33 560 Capacitor C1 JP4 33 560 Capacitor C4 JP5 16 5 800 Capacitor C3 C4 in series JP7 15 560 Capacitor C6 JP8 7 5 800 Capacitor C5 C6 in series JP9 15 ...

Page 19: ...pecifications This chapter lists the recommended operating conditions electrical and mechanical characteristics and dimensions Topic Page 2 1 Recommended Operating Conditions 20 2 2 Dimensions 24 Chapter 2 ...

Page 20: ...ormula below 1 0 2 0 Apeak P_VSP Peak pulse power input to transmitter power stage I_VSP V_VSP Duty Cycle 24 W V_ANT Antenna resonance voltage 250 380 Vpeak V_ANT 25 Antenna resonance voltage Pulse width setting 25 200 Vpeak V_ANT ATI Minimum antenna resonance voltage for correct operation of ATI 25 Vpeak V_VSL Supply voltage input for logic part 7 0 24 0 V DC I_VD External current load on interna...

Page 21: ...uty Cycle 0 625 The following methods can be used to measure the actual I_VSP value 1 Use a battery powered oscilloscope to measure the voltage drop across a 0 1 Ohm resistor placed in the DCIN line and then calculate the actual current using the formula I V R 2 If a battery powered oscilloscope is not available measure the potential at both sides of the 0 1 Ohm resistor signal probe with the GND ...

Page 22: ...s connected 2 0 2 5 3 0 mA Fan Out Low power Schottky compatible fan out of signals RXDT and RXCK 3 FanOut_Rl Low power Schottky compatible fan out of signal RXSS low level only 1 FanOut_Rh Low power Schottky compatible fan out of signal RXSS high level only see note below l_J1 Cable length for connecting J1 of RA RFM to a Control Module using flat cable 0 0 5 2 0 m l_CPS Cable length for connecti...

Page 23: ...1 µs µs t_ro_R Rise time of output signal RXSS no external connection 1 µs t_fo Fall time of output signal RXSS 1 µs tss_01Tl Propagation delay time from positive slope of TXCT to positive slope of RXSS signal maximum sensitivity 500 1000 1500 µs tss_10Tr Propagation delay time from negative slope of TXCT to negative slope of RXSS signal minimum sensitivity 50 100 200 µs Note Due to transponder pa...

Page 24: ...s otherwise noted Figure 7 Mechanical Dimensions RA RFM Note The heatsink is connected to the antenna resonator ground GNDA When connecting the heatsink to a housing the heatsink must be insulated from the housing 4 8mm 1 0 mm 16 0 mm 1 0mm 8 8mm 1 0 mm 9 9mm 1 0 mm 57 6 mm 1 0mm 70 36 mm 83 mm 1 0mm 93 mm 1 0mm 71 1mm ANT1 M3 Pressnuts ...

Page 25: ...February 2002 Specifications 25 Figure 8 Mechanical Dimensions Antenna Tuning Board ...

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Page 27: ...27 Installation This chapter shows how to install the RA RFM and specifies power supply requirements and connections Topic Page 3 1 Power Supply Requirements 28 3 2 Power Supply Connection 29 Chapter 3 ...

Page 28: ... around 50 kHz The harmonics of the generated field may interfere with the TI RFID receiver and therefore only linear power supplies or SMPS with a fundamental operating frequency of 200 kHz or higher are recommended Noise from power supplies or from interface lines may interfere with receiver operation It is recommended to add additional filters in series to the supply and interface lines if requ...

Page 29: ...nnected at the Control Module as shown in Figure 9 The grounds for the VSP VSL and the Control Module supply are connected together at a common ground Alternatively if the voltage drop across the VSP supply line is less than 0 5 V likely in this case the ground pins GND and GNDP may be connected together at the RA RFM If the system has a TI RFID Control Module the RA RFM ground pins GND and GNDP a...

Page 30: ...0 5 V otherwise the RA RFM will suffer damage Figure 9 External Ground Connection GND to GNDP TI RFID RF Module Customer Specific Controller Vsupply Ground Common Ground VSP 13 VSP 11 VSL 3 GND 1 GNDP 9 GNDP 7 Bridge VSL VSP Connector ST1 to TX power stage to Logic part Ground Logic Ground TX power stage R_GND ...

Page 31: ...Associated Antenna Systems This chapter discusses antenna requirements and antenna tuning procedures Topic Page 4 1 Antenna Requirements 32 4 2 Antenna Resonance Tuning 33 4 3 Tuning Procedure 34 Chapter 4 ...

Page 32: ...aided wire can be used In order to ensure that the transmitter and receiver function correctly the antenna must be tuned to the resonance frequency of 134 2 kHz For a detailed description of the antenna resonance tuning procedure refer to the next section Antenna Resonance Tuning To ensure that the antenna can be tuned to resonance with the Antenna Tuning Board the antenna inductance can only vary...

Page 33: ...one by using an oscilloscope or a voltmeter Figure 10 showing the necessary configurations Figure 10 Antenna Tuning Pick up Coil Configuration As the RA RFM has only to be tuned to the maximum voltage obtainable at the pick up coil any type of coil may be used the inductance being of little importance However if a pick up coil with a high inductance high number of windings and large size is used i...

Page 34: ...ld strengths Each antenna is tuned individually to the RA RFM and this results in a unique tuning jumper arrangement for this combination of antenna and RA RFM If a different antenna or RA RFM is connected the new combination must be tuned to resonance again 4 3 Tuning Procedure 1 Switch RA RFM power supply off 2 Calculate the required resonance capacitance see calculation method below 3 Set the t...

Page 35: ...tunb is the capacity which is adjusted on the Antenna Tuning Board C_deviation is the allowed tolerance within which the corresponding jumper setting is valid The columns Tuning Range and Cable Length show some examples of jumper settings for a particular antenna inductance and length The cable length can be between 5 and 120 meters The column V RF_max shows the maximum allowable resonance voltage...

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Page 37: ...37 Regulatory Safety Warranty Notices Topic Page 5 1 Regulatory Notes 38 5 1 1 FCC Notices U S A 38 5 1 2 CE Conformity Europe 38 Chapter 5 ...

Page 38: ... before operating or selling this system 5 1 2 CE Conformity Europe A CE Declaration of Conformity is available for the RFM at TI RFID Sales Offices The equipment complies with the essential requirements of the Telecommunication Terminal Equipment Act FTEG and the R TTE Directive 99 5 EC when used for its intended purpose Any device or system incorporating this module in any other than the origina...

Page 39: ... antenna and therefore the higher the Q factor of the antenna coil the higher the field strength generated by the RA RFM assuming that all other parameters remain unchanged The Q factor of the antenna itself depends on the cross sectional area of the wire the wire type the size of the antenna and the type of antenna gate or ferrite The larger the cross sectional area of the RF braided wire the hig...

Page 40: ... strength which is generated by the RA RFM since more power is fed into the antenna resonator by the transmitter power stage assuming that all other parameters remain unchanged See Appendix 2 The generated field strength can be measured in several ways It may be measured using a calibrated field strength meter or by measuring the antenna resonance voltage using an oscilloscope and then calculating...

Page 41: ...strength As default no resistor is connected thus selecting the maximum pulse width of 50 and the maximum field strength By connecting a shorting bridge the smallest pulse width of approximately 0 is selected Table 16 provides an overview of oscillator signal pulse width and corresponding field strength reduction when different oscillator signal pulse widths are selected by connecting different re...

Page 42: ... that the antenna resonance voltage does not exceed 200 Vp when the selected oscillator signal pulse width setting is smaller than 25 Note The pulse width for an oscillator signal pulse width setting of 5 and smaller is extremely short The pulse response of the RA RFM transmitter power stage to this short pulse is different for each unit In order to have reproducible field strength values for diff...

Page 43: ...evel has to be adjusted This needs to be done after the antenna has been tuned to resonance It is recommended to use a small screwdriver to adjust the RXSS threshold level The R409 potentiometer is located on the upper side of the RA RFM board near connector switch SW1 Turning the potentiometer all the way clockwise right hand stop results in minimum threshold sensitivity i e the RXSS signal will ...

Page 44: ...ule assumes that another reading unit is transmitting and continually tries to synchronise to this other reading unit As a result the reading repetition rate decreases from approximately 10 down to 5 readings per second This reading unit can additionally no longer synchronise to other reading units causing interference with other reading units and reading at all reading units becomes impossible Th...

Page 45: ...s effect depends on three factors 1 Antenna size The larger the size of the antennas the further the distance between the antennas must be so that this effect does not occur 2 Magnetic field strength The stronger the generated magnetic field strength the further the distance between the antennas must be such that the effect does not occur 3 Orientation and distance between antennas Increasing the ...

Page 46: ... 17 Maximum Distances between Antennas Antenna type Distance D1 m Distance D2 m RI_ANT_S02 RI_ANT_S02 0 8 1 0 RI_ANT_G01 RI_ANT_G01 1 7 1 5 RI_ANT_G02 RI_ANT_G02 1 3 1 0 RI_ANT_G04 RI_ANT_G04 2 0 1 7 This effect will not occur if the transmitters of different RA RFMs are operated from the same oscillator signal This is the reason why the pulse width modulated oscillator signal is accessible at the...

Page 47: ...us none of the oscillator SLAVE RFMs are able to transmit The read cycles of all RA RFMs connected to this CPS interface must be synchronized and all read cycles must occur simultaneously Refer to the Hardware and Software Manuals for the TI RFID Control Modules for more information about the necessary wiring and settings for synchronization of the RA RFM when using transmitter Carrier Phase Synch...

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Page 49: ...e radiated noise Note The RA RFM has a built in function for suppression of common mode noise coupled to the antenna Method for detecting and distinguishing between noise types The principle of this procedure is to eliminate any conducted noise from the supply and all interface lines In order to do this test the RA RFM must be powered from a battery for example 9 V 20 mA in order to eliminate any ...

Page 50: ...tage more than approximately 1 0 VDC then the problem is radiated noise Eliminate noise sources or try special antennas e g noise balanced antennas 1 When the configuration of Figure 12 shows good noise conditions RSTP voltage less than 1 0 VDC then the problem is conducted noise 2 Change the configuration so that the interface lines are again connected to the RA RFM with the transmitter still swi...

Page 51: ...on If a higher current is needed dump type ZX18 may be used this diode having a 12 5 W power dissipation 2 The Common Mode Choke Coil and the capacitors C1 and C2 are used to reduce the conducted noise coming to the RA RFM via the supply lines 3 All input and output signals should be protected with 5 6 V Zener diodes The specified type can dump 1 3 W 4 The coils L1 to L6 are ferrite beads and shou...

Page 52: ...mponents must be mounted close to the RA RFM with the shortest possible wiring C1 100 nF Ceramic R1 1 Ohm 2W V1 Varistor 420V e g Siemens S10V 520K420 C2 100 µF low ESR R2 R3 R4 R5 R6 R7 22 Ohm 0 25W CHOKE Common Mode Choke Coil L1 L2 L3 L4 L5 L6 Ferrite beads D1 ZY18 resp ZX18 D2 D3 D4 D5 D6 D7 BZX85C5V6 ...

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