Texas Instruments RI-MOD-TX2A User manual

Texas Instruments
Registration
and
Identification
System
Multiplexer
Module
RI-MOD-TX2A (discontinued)
RI-MOD-TX4A (discontinued)
Reference Manual
11-06-21-034 18 November 1996

Multiplexer Module (TX2A/TX4A) 18 November 1996
MUX-2
Edition Notice: Second Edition - November 1996
This is the second edition of this manual, it describes the following equipment:
TIRIS 2-channel Transmit/Receive Multiplexer Module RI-MOD-TX2A
TIRIS 4-channel Transmit/Receive Multiplexer Module RI-MOD-TX4A
The text on page 13 about Jumper J5 has been changed to include the S25x0 Reader and a new
figure (figure 6) showing how to connect the Multiplexer Module to the S25x0 has been
included.
Texas Instruments reserves the right to change its products or services at any time without
notice. TI provides customer assistance in various technical areas, but does not have full access
to data concerning the uses and applications of customer's products. Therefore TI assumes no
responsibility for customer product design or for infringement of patents and/or the rights of
third parties, which may result from assistance provided by TI.
The TIRIS logo and the word TIRIS are registered trademarks of Texas Instruments
Incorporated.
Copyright 1996 Texas Instruments Incorporated.
All rights reserved.

18 November 1996 Multiplexer Module (TX2A/TX4A)
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Contents
1. Introduction ...............................................................................................................5
1.1 General .................................................................................................................5
1.2 Product Description .............................................................................................5
1.3 Product Option Coding ........................................................................................5
1.4 Conventions .........................................................................................................5
2. Product Function .......................................................................................................6
2.1 Description ..........................................................................................................6
2.2 Multiplexer Connectors and Jumpers ..................................................................11
2.2.1 Connectors ..................................................................................................11
2.2.2 Jumpers .......................................................................................................13
3. Specifications ............................................................................................................14
3.1 Absolute Maximum Ratings ................................................................................14
3.2 Recommended Operating Conditions ..................................................................14
3.3 Electrical Characteristics .....................................................................................15
3.4 Timing Characteristics .........................................................................................15
3.5 Mechanical data ...................................................................................................16
4. Installation and Use of the 4 Channel Multiplexer Module ......................................17
4.1 Power Supply .......................................................................................................17
4.1.1 Supply Requirements ..................................................................................17
4.2 Antenna Requirements ........................................................................................17
4.3 Connecting Cable ................................................................................................18
4.4 Antenna Resonance Tuning..................................................................................18
Figures
Figure 1: Top View ........................................................................................................7
Figure 2: Block Diagram ................................................................................................7
Figure 3: Configuration of TIRIS Standard TX/RX Antennas .......................................8
Figure 4: Configuration for Input Signals CSA, CSB and Enable .................................8
Figure 5: Connection of Multiplexer to RF Module .......................................................9
Figure 6: Connection of Multiplexer to S25x0 Reader...................................................10
Figure 7: Jumper Locations.............................................................................................13
Figure 8: Module Layout and Dimensions .....................................................................16
Tables
Table 1: J1 Pin Functions ...............................................................................................11
Table 2: J4 Pin Functions ...............................................................................................11
Table 3: J3 Pin Functions ...............................................................................................12
Table 4: J6 Pin Functions ...............................................................................................12
Table 5: TX/RX Channel Selection ................................................................................12
Table 6: Size and Weight ...............................................................................................16
Table 7 Power Supply Ripple Specifications .................................................................17
Table 8: Antenna Characteristics ...................................................................................18

Multiplexer Module (TX2A/TX4A) 18 November 1996
MUX-4

18 November 1996 Multiplexer Module (TX2A/TX4A)
MUX-5
1. Introduction
1.1 General
This document provides information about the TIRIS Transmit/Receive Multiplexer (MUX)
Modules RI-MOD-TX2A and -TX4A. It describes the modules and how to install them.
1.2 Product Description
The 2 Channel Multiplexer Module allows the use of 2 transmit/receive (TX/RX) antennas with
one RF Module and the 4 Channel Multiplexer Module allows the use of up to 4 transmit/receive
(TX/RX) antennas with one RF Module.
The Multiplexer is connected between the RF Module and the TX/RX antennas. In this way up to 4
TX/RX antennas can be operated from one RF Module. The active antenna (TX/RX channel) is
selected by two digital input signals.
1.3 Product Option Coding
For product and ordering numbers of RF Module, Antennas, Control Modules, combinations of
these and Accessories, please contact your local TIRIS Application Center.
The Module RI-MOD-TX2A is the 2 channel Transmit/Receive Multiplexer
The Module RI-MOD-TX4A is the 4 channel Transmit/Receive Multiplexer
1.4 Conventions
Certain conventions are used in this document in order to display important information, these
conventions are:
WARNING
A warning is used where care must be taken, or a certain 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 Module.
Note: Indicates conditions which must be met, or procedures which must be followed, to
ensure proper functioning of the Module.
HINT: Indicates information which makes usage of the Module easier.

Multiplexer Module (TX2A/TX4A) 18 November 1996
MUX-6
2. Product Function
2.1 Description
The 2 Channel Multiplexer Module allows the use of 2 transmit/receive (TX/RX) antennas with
one RF Module and the 4 Channel Multiplexer Module allows the use of up to 4 transmit/receive
(TX/RX) antennas with one RF Module.
The Multiplexer is connected between an RF Module and the TX/RX antennas. All antennas can
be disabled by removing one jumper.
The supply voltages and channel selection signals are connected via a 4-pin connector.
The connection to the RF Module and to the antennas is made via two screw block terminals.
The channel select input signals, connected to a data processing unit (for example: TIRIS Series
2000 Control Module, or a customer designed control unit), are Low Power Schottky TTL and
HCMOS Logic compatible.
The Multiplexer includes circuitry to reduce crosstalk of transmit function.
There are four connectors on the Multiplexer in total, these are:
J1 which is used to connect the supply voltage and channel select signals
J3 which is used to connect up to 4 TX/RX antennas
J4 the antenna resonator connector, which is used to connect the Multiplexer board to
the antenna terminals of the RF Module
J6 which can be used to connect the Multiplexer ground to earth
The Multiplexer can be mounted by means of four M3 mounting bolts on the under-side of the
module.
A layout of the Multiplexer viewed from the top is shown in figure 1 (the parts in dotted lines are
not mounted for the Module RI-MOD-TX2A). A block schematic of the Multiplexer is shown in
figure 2. The Multiplexer is described in the following section.

18 November 1996 Multiplexer Module (TX2A/TX4A)
MUX-7
1
8
1
J3
2
1
J7
J4
J5
J6
J2
J1
Connector for Power Supply and
for channel select signals
V_IN GND
CSA
CSB
Connection to
RF Module
antenna terminals
TX/RX
antenna 4 TX/RX antenna 1
TX/RX
antenna 2
TX/RX
antenna 3
Figure 1: Top View
The Multiplexer switches the selected antenna to the RF Module. The Multiplexer switches both
the transmit and receive functions of the antenna. Low resistance high voltage switches
(MOSFETs) are used to switch the antenna connection because of the high voltage used during
transmitting.
ANT
GNDTX
Figure 2: Block Diagram

Multiplexer Module (TX2A/TX4A) 18 November 1996
MUX-8
All multiplexed antennas have one common terminal, which is the antenna terminal ANT. The
other antenna terminals are connected to ground GNDTX via a switch. The characteristics of the
TX/RX antennas are shown in figure 3.
Figure 3: Configuration of TIRIS Standard TX/RX Antennas
For more details refer to Section 4 “Installation and Use of the 4 Channel Multiplexer”.
The active TX/RX channel is selected by the two binary weighted channel select signals CSA and
CSB, table 5 shows the binary configuration needed to select each channel. The configuration of
the input signals CSA and CSB and the Enable signal (ENTX-) is shown in figure 4.
Figure 4: Configuration for Input Signals CSA, CSB and Enable
The Multiplexer has built-in voltage regulators to supply the logic part and the MOS FET drivers
with regulated voltage.
The input supply voltage must be connected to the pins V_IN and GND of connector J1. The input
voltage needs to be stabilized (i.e. DC), but not regulated and can be between 10 and 24 V.
Note: The Multiplexer must not be supplied by Switched Mode Power Supplies (SMPS). This
is because most SMPS operate at frequencies around 50 kHz. The harmonics of the
generated field can interfere with the TIRIS receiver. Therefore only use linear power
supplies, or SMPS with a fundamental operating frequency of 200 kHz or higher.
Figure 5 shows how the Multiplexer should be connected to the Power RFM and how the TX/RX
antennas should be connected. Figure 6 shows how the Multiplexer should be connected to the
S25x0 Reader, how the TX/RX antennas and how the power should be connected.

18 November 1996 Multiplexer Module (TX2A/TX4A)
MUX-9
J1
1
8
1
J3
J7
J4
J5
J6
J2
Figure 5: Connection of Multiplexer to RF Module
Note: The lines ANT and GNDTX, which connect the Multiplexer board to the RF Module
must be connected as shown. They must not be swapped, otherwise the Multiplexer will
not work.
The antennas must (as usual) be tuned to resonance together with the RF Module. As the
Multiplexer does not include the feature to tune the antennas individually to resonance, the tuning
has to be done in such a way that the optimum reading performance is achieved for each antenna.
We recommend using the TIRIS Add-on Module ‘Dynamic Auto Tuning’, which allows each
antenna to be individually and automatically tuned to resonance.
HINT:If you do not have the Dynamic Auto Tuning Module in your system we strongly
recommended that you use the TIRIS Antenna Tuning Indicator (ATI), for simple
monitoring of antenna resonance tuning.

Multiplexer Module (TX2A/TX4A) 18 November 1996
MUX-10
Notes: If you are not using the TIRIS Add-on Module ‘Dynamic Auto Tuning’ remember that
the antennas are not individually tuned to resonance when used together with the
Multiplexer. So either tune the RF Module to the best resonance condition for all the
antennas being used, or include a ‘Dynamic Auto Tuning’ Module in your system.
Enabling a TX/RX channel enables both the transmit and receive function. However
disabling a TX/RX channel only disables the Transmit function (charge-up of a
transponder). The transmit function of a disabled channel is never completely switched
off, as there is still some coupling of the antenna resonance voltage from the active
channel to the disabled channels via the parasitic capacitance of the MOSFET switch.
This means that a transponder could still be charged-up at a distance of a few
centimetres from a disabled TX/RX antenna.
The receive function at a switched off antenna is never completely switched off, because
there is still reasonable coupling via the parasitic capacitance of the MOSFET switch.
As the TIRIS receiver is very sensitive, the small voltage which is coupled via this
capacitance, can still be enough to receive a transponder signal. Basically the receive
performance at a switched off TX/RX antenna is reduced by about 50% compared to an
enabled TX/RX antenna.
CAUTION: The RF Module must not be operated in continuous transmit mode.
WARNING
Care must be taken when handling the RF Module. HIGH
VOLTAGE across the antenna terminals and all antenna resonator
parts could be harmful to your health. If the antenna insulation is
damaged it should not be connected to the RF Module.
21
43 2 1
ANTENNAS
14 - 24 VDC
GND
4 WAY MUX
1 2 3 4
CHANNEL SELECT SIGNAL B
CHANNEL SELECT SIGNAL A
1 2 3 1 2 3 4 5 6 7 8 91 2 3 4 5 6
1 2 31 2 3 4 5 6 1 2
1 2 3 4 5 6 7 8 9 101112131415
1 21 2 3 4 5 6 123456
1 2 3 4 5 6 123456 1 2 3 4 5 6 1 2
CPS
O.K.
O.K.
MAX
PWM
EMI
ACTIVE DAT
CTL
RFMRS422CTL
O.C. - I/O
OFF / ON
RS232
RXSS- (EMI)
GND
GEN. I/O
S2510 MIN
SYNC
RX-ANT ANT1 ANT2
4 A SLOW BLOW
+ - DC IN
J5 out
+== == −
Figure 6: Connection of Multiplexer to S25x0 Reader

18 November 1996 Multiplexer Module (TX2A/TX4A)
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2.2 Multiplexer Connectors and Jumpers
2.2.1 Connectors
Table 1 lists the pin functions for connector J1. The connector type is a 4-pin Phoenix connector
with 5.08 mm pin spacing.
Tables 2 lists the pin functions for the antenna screw block terminal J4. The Multiplexer is
connected to the RFM antenna terminals via connector J4.
Table 3 lists the pin functions for the antenna screw block terminal J3. The TX/RX antennas must
be connected to the RFM antenna terminals via connector J3.
Table 4 lists the pin function for ground post J6.
Table 5 shows the logic switching of the active channel.
All connectors are accessible from the top.
Table 1: J1 Pin Functions
Pin# Signal Direction Description
1 V_IN IN Supply voltage input
2 GND IN Ground
3 CSA IN Channel Select signal CSA (LSB)
4 CSB IN Channel Select signal CSB (MSB)
Table 2: J4 Pin Functions
Pin# Signal Direction Description
1 ANT IN/OUT Antenna resonator signal. This pin must be connected to
signal ANT of the S2000 RFM, or ANT1 if you are using
the Power RFM.
2 GNDTX IN/OUT Antenna ground. This pin must be connected to ground
GNDA of the S2000 RFM, or ANT2 if you are using the
Power RFM.

Multiplexer Module (TX2A/TX4A) 18 November 1996
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Table 3: J3 Pin Functions
Pin# Signal Direction Description
1 A_OUT4 IN/OUT Switched antenna signal (switched to ground GNDTX,
when active). Connected to TX/RX antennas.
2 ANT IN/OUT Antenna resonator signal. Connected to TX/RX antennas.
3 A_OUT3 IN/OUT Switched antenna signal (switched to ground GNDTX,
when active). Connected to TX/RX antennas.
4 ANT IN/OUT Antenna resonator signal. Connected to TX/RX antennas.
5 A_OUT2 IN/OUT Switched antenna signal (switched to ground GNDTX,
when active). Connected to TX/RX antennas.
6 ANT IN/OUT Antenna resonator signal. Connected to TX/RX antennas.
7 A_OUT1 IN/OUT Switched antenna signal (switched to ground GNDTX,
when active). Connected to TX/RX antennas.
8 ANT IN/OUT Antenna resonator signal. Connected to TX/RX antennas.
Table 4: J6 Pin Functions
Pin# Signal Direction Description
1 GND IN/OUT Multiplexer Ground
Table 5: TX/RX Channel Selection
Signal
CSA Signal CSB Active TX/RX antenna at Connector
LOW LOW Channel 1 J3, pins 7 and 8
HIGH LOW Channel 2 J3, pins 5 and 6
LOW HIGH Channel 3 J3, pins 3 and 4
HIGH HIGH Channel 4 J3, pins 1 and 2

18 November 1996 Multiplexer Module (TX2A/TX4A)
MUX-13
2.2.2 Jumpers
There are 3 jumpers on the Multiplexer, for location of the jumpers please refer to figure 7. The
jumpers are described in detail following:
J2
J5
J7
Figure 7: Jumper Locations
J2
This jumper is used to enable all TX/RX channels. When this jumper is open, all TX/RX channels
are disabled. When it is closed, all TX/RX channels are enabled.
Default: J2 closed
J5
This jumper is used to connect the antenna terminal GNDTX (pin 2 of connector J4) to the
Multiplexer ground GND.
When using the Multiplexer together with the S2000 RFM, this jumper has to be closed. When
using the Multiplexer together with the Power RFM or the S25x0 Reader, this jumper must be
opened.
Default: J5 open
J7
This jumper is used to connect the Multiplexer mounting bolt to ground GND. The Multiplexer can
be earthed via the mounting bolt when necessary.
Default: J7 open

Multiplexer Module (TX2A/TX4A) 18 November 1996
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3. Specifications
3.1 Absolute Maximum Ratings
over operating free-air temperature range (unless otherwise noted)
Supply voltage V_IN +26 V
Antenna resonance voltage V_ANT 250 Vpeak
Operating free-air temperature range T_oper -25 to +70 oC
Storage temperature range T_store -40 to +85 oC
Notes: Free-air temperature: air temperature immediately surrounding the Multiplexer module.
If the module is incorporated into a housing, it must be guaranteed by proper design or
cooling that the internal temperature does not exceed the absolute maximum ratings.
CAUTION: Exceeding absolute maximum ratings may lead to permanent damage to the
Module. Exposure to absolute-maximum-rated conditions for extended
periods may affect device reliability.
The RF Module must not be operated in continuous transmit mode.
3.2 Recommended Operating Conditions
at a free-air temperature of 25 oC
Symbol Parameter min. typ. max. Unit
V_V_IN TX/RX Mux Module supply voltage 10.0 12.0 24.0 V DC
I_V_IN Supply current for Multiplexer Module 60 120 mA
V_ANT Antenna resonance voltage 230 Vpeak

18 November 1996 Multiplexer Module (TX2A/TX4A)
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3.3 Electrical Characteristics
Symbol Parameter min. typ. max. Unit
R_Cha Additional antenna resonator resistance per
channel 0.2 Ohm
V_U1 Internal stabilized logic supply voltage 4.5 5.0 5.5 V
V_U2 Internal stabilized driver supply voltage 10.8 12.0 13.2 V
ViL Low level input voltage of signals CSA,
CSB and Enable signal 0 0.8 V
ViH High level input voltage of signals CSA,
CSB and Enable signal (J2) 2.4 5.0 V
Fan-In Low Power Schottky compatible fan-in of
signals CSA, CSB and Enable signal (Iin = -
400 µA)
1-
3.4 Timing Characteristics
Symbol Parameter min. typ. max Unit
f_TX Transmit frequency 134.18 134.20 134.22 kHz
t_ri
t_fi Rise and fall time of input signals CSA, CSB and Enable signal 1 1µs
µs
t_short Maximum short circuit time of antenna
terminals 10 s
CAUTION: The parameter t_short is determined by the RF Module circuitry and refers to
static short circuit of the antenna terminals. Shorting the antenna terminals
during operation may cause permanent damage to the RF Module.

Multiplexer Module (TX2A/TX4A) 18 November 1996
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3.5 Mechanical data
The mechanical size and weight is given in Table 6. Further mechanical details are provided in
figure 8. All of the measurements given in figure 8 have a tolerance of ±0.25 m.
J1
1
J2
J5
J6
8
1
J3
2
1
J7
85.09
90.17
5.08
5.08
15.49
85.54
130.81
135.89
74.01
64.00
95.25
J4
Figure 8: Module Layout and Dimensions
Table 6: Size and Weight
Parameter typical Unit
Length 135.89 ±1.0 mm
Width 90.17 ±1.0 mm
Height(including mounting bolts) 36.0 ±2.0 mm
Weight of complete Multiplexer
RI-MOD-TX4A
RI-MOD-TX2A 260 190 Grams Grams

18 November 1996 Multiplexer Module (TX2A/TX4A)
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4. Installation and Use of the 4 Channel Multiplexer Module
4.1 Power Supply
4.1.1 Supply Requirements
Note: The Multiplexer must not be supplied by Switched Mode Power Supplies (SMPS). This
is because most SMPS operate at frequencies around 50 kHz. The harmonics of the
generated field can interfere with the TIRIS receiver. Therefore only use linear power
supplies, or SMPS with a fundamental operating frequency of 200 kHz or higher.
Noise from power supplies or noise on the interface lines can interfere with the RF Module’s
receiver. Therefore, if the application requires it, it may be necessary to place additional filters in
series to the supply and interface lines. For more details refer to RF Module Operating Manual.
In order to guarantee full RF Module performance, the power supplies should fulfill the
specifications for ripple voltage given in Table 7.
Table 7: Power Supply Ripple Specifications
Supply type Maximum allowed
Ripple Voltage Allowed Ripple Frequency
Unregulated VCL supply 30 mVrms 0 to 100 kHz maximum
(sinusoidal)
4.2 Antenna Requirements
The transmit antenna for the RF Module (which is used to charge up the transponder) is a coil
(see figure 3), this coil is part of the antenna resonant circuit of the RF Module.
In order to achieve the high voltages at the antenna resonant circuit and thus high field strength at
the antenna for charge-up (transmit) function, the antenna coil must have a high quality factor.
The recommended quality factor for proper operation is listed in table 8. The quality factor of the
antenna is decreased when the Multiplexer is used, a maximum resistance of 200 mOhms is
added per channel, which reduces the quality factor of TIRIS Standard antennas to about 55 (the
original quality factor is approximately 100).
For proper operation of the transmitter and receive function, the antenna has to be tuned to the
resonance frequency f_TX. For a detailed description of the antenna resonance tuning procedure,
see the RF Module Operating Manual.
To ensure that the antenna can be tuned to resonance with the connected RF Module, the antenna
inductance can only vary within the limits given in table 8.

Multiplexer Module (TX2A/TX4A) 18 November 1996
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Table 8: Antenna Characteristics
Parameter Conditions min. typ. max. Unit
L_ANT Antenna inductance range, within which
the antenna can be tuned to resonance
using the tuning coil on the RF Module
26.0 27.0 27.9 µH
Q_ANT Recommended quality factor of antenna
coil for proper operation 100 -
A_ANT_
TX/RX Quality factor of TIRIS Standard Antennas, when used together with the
Multiplexer
55 -
4.3 Connecting Cable
We recommend that the cable between the RFM and the Multiplexer is low resistive (for
example: RF Litz wire 120 x 0.1 mm, or loudspeaker cable with at least the same cross-sectional
area) with a maximum length of 30 cm. If the connecting cable is longer than 20 cm it will affect
the quality factor and inductance.
4.4 Antenna Resonance Tuning
In order to achieve the high charge-up field strength, the antenna resonator frequency must be
tuned to the transmitter frequency f_TX (tuning to resonance).