RX1M-XXX-10 RADIOMETRIX [Radiometrix Ltd], RX1M-XXX-10 Datasheet - Page 9

• Manufacturer Part Number: RX1M-XXX-10
• Description: VHF Narrow Band FM multi channel radio Transmitter & Receiver
• Manufacturer: RADIOMETRIX [Radiometrix Ltd]

Application circuits
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.
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. 1k )
according to the current requirement to produce satisfactory brightness on the LED used.
Radiometrix Ltd
PC serial port
SGD
TXD
SGD
TXD
3
2
4
5
1
Figure 7: TX1M and RX1M interfaced to host microcontroller and serial port for configuration
Transmit Enable
1
3
2
4
5
9
6
7
8
6
8
9
7
Transmit Enable
Parallel
Channel
Select
Data Out
Parallel
Channel
Select
TX
TX
1k
0V (C1)
TXE (C2)
TXD (C3)
AF in (C4)
+4.4V out (C5)
PGM (C6)
GND
P1 (C8)
P2 (C9)
P3 (C10)
1k
(C7)
0V (C1)
TXE (C2)
TXD (C3)
AF in (C4)
+4.4V out (C5)
PGM (C6)
GND
P1 (C8)
P2 (C9)
P3 (C10)
Figure 6: Test circuit of TX1M and RX1M
(C7)
Antenna
4.5 - 15V
Antenna
4.5 - 16V
TX1M/RX1M Data Sheet
4.5 - 15V
4.5 - 15V
Antenna
Antenna
+4.4V out (C5)
+4.4V out (C5)
AF out (C3)
AF out (C3)
GND (C6)
PGM
RXD (C4)
GND (C6)
PGM
RXD (C4)
P3 (C10)
P3 (C10)
SQF (C2)
SQF (C2)
RSSI (C1)
P1 (C8)
P2 (C9)
P1 (C8)
P2 (C9)
0V (C1)
(C7)
(C7)
100nF
Parallel
Channel
Select
CD
ADC or A meter
CD
ADC
Data In
VDD
Parallel
Channel
Select
100nF
Data out
+4.4V
6
7
8
9
PC serial port
1
2
4
5
6
7
8
9
3
page 9
2
4
5
1
3
TXD
SGD
TXD
SGD