Application circuits
Ante nna
Ante nna
ADC or
µ
A me te r
RSSI (C1)
SQF (C2)
0V (C1)
Tra nsm it Ena b le
TXE (C2)
CD
AF out (C3)
RXD (C4)
+ 4.4V out (C5)
GND (C6)
PGM (C7)
P1 (C8)
TXD (C3)
AF in (C4)
+ 4.4V out (C5)
PGM (C6)
GND(C7)
P1 (C8)
Da ta out
TX
1kΩ
1
1
6
+ 4.4V
100nF
6
7
8
9
2
3
2
7
Pa ra lle l
Cha nne l
Se le c t
3
Pa ra llel
Cha nne l
Se le ct
TXD
TXD
4.5 - 15V
4.5 - 15V
P2 (C9)
P2 (C9)
8
9
4
5
4
5
P3 (C10)
P3 (C10)
SGD
SGD
Figure 6: Test circuit of TX1M and RX1M
TX1M/RX1M can be configured using any PC/Laptop/PDA having a serial port and modem/terminal
program. TXD (pin 3) of DB9M connector can be directly wired to PGM (pin C7) of the TX1M/RX1M and
SGN (pin 5) of DB9M connector should be connected to common ground pins.
The whole frequency/channel table is user reconfigurable to 128 channels within 2MHz band of
supplied frequency subject to regulatory band limits.
Ante nna
Ante nna
0V (C1)
SQF (C2)
ADC
0V (C1)
Tra nsmit Ena ble
Da ta Out
TXE (C2)
TXD (C3)
AF in (C4)
+ 4.4V out (C5)
PGM (C6)
GND(C7)
P1 (C8)
AF out (C3)
RXD (C4)
+ 4.4V out (C5)
GND (C6)
PGM (C7)
P1 (C8)
CD
TX
Da ta In
VDD
1kΩ
1
1
6
7
8
9
6
7
8
9
2
2
3
100nF
3
TXD
TXD
Pa ra llel
Cha nnel
Sele ct
Pa ra llel
Cha nnel
Selec t
4.5 - 15V
4.5 - 16V
4
5
P2 (C9)
4
5
P2 (C9)
P3 (C10)
P3 (C10)
SGD
SGD
PC se ria l p ort
PC se ria l p ort
Figure 7: TX1M and RX1M interfaced to host microcontroller and serial port for configuration
TX1M and RX1M can be directly interfaced to a host microcontroller which can generally be powered by
the regulated +4.4V output on pin 5. Three I/O pins on the microcontroller port can be assigned to select
the first 8 channels on frequency table of the appropriate band for which the module is configured by
pulling the P1-P3 pins low. Channel select pins of TX1M and RX1M have internal pull-up to 4V supply
rail, hence channel selection operate on inverted logic.
Digital Received Data Output (RXD) pin on the RX1M is an open collector output, which should be
pulled-up to required voltage swing level (e.g. +4.4V or Vcc).
RX1M has an automatic noise squelching function which is activated when there is not any RF signal at
detectable level on the channel or if the non-coherent noise like interference level is high enough to
block any weak RF signal from being received. SQF is provided as an open-collector output for
monitoring which should be pulled-up to required voltage swing level. SQF output will jump to pull-up
voltage level if received RF signal level at the RF In/Out pin of the module is about 3dB below the level
required to produce 12dB SINAD level on demodulated AF Output signal. SQF pin can be connected to
an LED to act as a Carrier Detect indicator. Pull-up resistor value should be reduced (e.g. 1kΩ)
according to the current requirement to produce satisfactory brightness on the LED used.
Radiometrix Ltd
TX1M/RX1M Data Sheet
page 9
RADIOMETRIX [ RADIOMETRIX LTD ]
