q-Tech Q71B User manual
Q71B –1200 bps FSK Radio Modem
for DATRAN Base Stations
Quick Start Guide
Q71B Base Station Modem –Quick Start Guide –v1.2 –May 2022
www.qtech.co.nz Tel: 03 3663713
Introduction
The Q71B Base modem is used at DATRAN Base Stations and provides the
communication interface to 1200bps analogue radio networks.
The Q71B Base modem is a direct replacement for the previous Q70 modem and uses the
default DATRAN comms port settings of 1200 baud, odd parity, 8 data bits,1 stop bit.
Each Q71B Base modem, part number PD9310-Base, is supplied with:
Qty 1x Q71B modem
Qty 1x Serial cable - Q71B modem to radio (RJ12 to D15 Male)
Qty 1x Serial cable - Q71B to PC (RJ45 to D9 Female)
Qty 1x 12V DC Plug pack, AC mains Input
An optional cable is available to connect Moxa NPort devices, part number CB-Q71-NPort.
If you require a Q71B modem for use with a DATRAN RTU, please refer to PD9310-Q82,
which comes with suitable cables and the correct jumper settings.
Q71B Base Station Modem –Quick Start Guide –v1.2 –May 2022
www.qtech.co.nz Tel: 03 3663713
Modem Connections
Serial Connector –RJ45
The connector is labelled “Base PC” and connects to the
DATRAN Base Station PC via the D9 female connector.
Pin Number Function
1 Data carrier detect (DCD) from modem to terminal.
2 Receive data from modem to terminal.
3 Transmit data from terminal to modem.
4 Not Used.
5 Signal ground.
6 Not Used.
7 Ready to Send (RTS) from terminal to modem.
8 Not Used
9 Not Used.
Radio Connector - RJ12
The connector is labelled “Radio” and connects the
modem to the audio interface in the radio.
Pin 1 is on the left-hand side, nearest the fixing screw.
The default cable supplied is part number CAB-Q71-Q82 which is suitable for Tait
TM91xx/TM81xx radios installed with a Q82 audio Interface.
Pin Number Function
1 Transmit and receive audio data.
2 Transmit and receive audio data.
3 Transmitter key power.
4 Transmitter key from radio.
5 Ground.
6 Busy from radio.
Q71B Base Station Modem –Quick Start Guide –v1.2 –May 2022
www.qtech.co.nz Tel: 03 3663713
Power Supply Connector
The 3 pin connector is for a 8-13.8V DC input.
The connector is the same as the previous Q70 modem
to simplify upgrades.
Pin Number Function
1 Ground
2 DC Supply 8 to 13.8V DC
3 Not Connected
The Q71B Base modem is supplied with a 12V DC plug pack with a pre terminated power
connector.
Status Indications
LED status Indication
PWR Power applied
Rx Modem is receiving
Tx Modem is transmitting
Modem Configuration
QTech supply Q71B Base modems preconfigured, no further configuration is required.
The three jumper settings of the Base modem are shown below, all are aligned towards
the “PC”label.
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