User's Manual

Jotron AS| TR7750C: Operators Manual  Installation
Page 4-22
P/N: 84748 (G)
4.7.4 Receiver, main / backup configuration
By connecting the alarm output from one (main) receiver to the select input on a backup unit, it is
possible to perform automatic switching between them. In this way, if a main transmitter detects an
internal failure, it can be set up to enter into standby mode and stop reception of signals. The alarm
signal will also signal to a backup unit to take over the receive function.
Figure 4.7-5, Main / Backup receiver
Step
Description
Reference
1
Connect the alarm_out signal (p.1,2) from AUX1 on the main
receiver to the select_in signal (p.3.6) on AUX1 on the standby
receiver. The connection can be done via a distribution panel or by
making a special with RJ45 connectors in each end. The cables
used should be of the same quality as a CAT5E network cable and
the screen should be connected in the plugs.
3.4.4 – AUX1 connector
2
Set Alarm config, Alarm pin pullup to Enabled (default)
5.8.3 – Interface config group
3
Set Alarm config, Select polarity to Low (default)
5.8.3 – Interface config group
4
Set the main receiver Operation mode to Main
5.8.1 – Radio control group
5
Set the backup receiver Operation mode to Norm (default)
5.8.1 – Radio control group
6
Connect separate antennas to the two receivers.
Alternatively use an external antenna change over unit (ACU) in
order to switch the antenna between the main and backup
receivers. The antenna change over unit can be controlled by the
alarm signal on the main unit.
The antenna connection can also be done via a pair of
main/backup transmitters.
Table 4.7-5, Main/backup configuration, receivers