User's Manual

Jotron AS| TR7750C: Operators Manual  Installation
Page 4-3
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distribution panel with RJ45 connectors, standard Cat5E, ethernet cable should be used. This is a
good quality, screened cable, with 1 to 1 connections between the two connectors.
Below is an overview of the signals available and their primary use. Refer to chapter 3.2 and 0 for and
overview of the different connectors.
4.6.1 REM connector (receiver) and RX connector (transmitter)
TX - REM/RX RX - REM PIN NAME DESCRIPTION
Pin no Pin no
1 1
RS485+
RS485 - serial communication
2 2
RS485-
RS485 - serial communication
3 3
LINE_P
RX Audio 600ohm balanced
4 4
TX BUSY
TTL L=transmitting (RX pullup)
5 5
RX BUSY
TTL L=receiving (TX pullup)
6 6
LINE_N
RX Audio 600ohm balanced
7 7
ALARM
Alarm (TTL) I/O TRX alarm
8 8
GND
Ground
CABLE
4 pairs
RJ45 - Cat 5E, FTP
Table 4.6-1, Transceiver, transmitter – receiver interconnections
The RX connector on the transmitter unit has a special function, and is normally used only in a
“transceiver” configuration.
When connecting the signals on the transmitter RX connector with the signals on the receivers REM
connector, the following functionality is added to the transmitter and receiver:
 The receiver audio line (p.3 and p.6) is input to the transmitter.
This enables the possibility to monitor the audio from the receiver from the transmitter
headphone connector, allowing only one plug to be used for a combined
headset/microphone.
In addition, it enables the possibility to use a 2 wire interface to the transmitters audio input
line for the combined transmitter and receiver audio.
Finally, it enables the functionality to monitor both the transmitted audio and the received
audio on the monitor output (TA-AUX2) line on the transmitter.
 A RX Busy signal (p.5) is input to the transmitter from the receiver.
This signal signals the transmitter that the RX is busy. This is used in VDL operation.
 A TX Busy signal (p.4) is output from the transmitter to the receiver.
This signal signals the receiver that the TX is busy (transmitting). This is used in VDL
operation, and to mute the receiver while transmitting (see table below).
 A receiver alarm in/out is connected to the transmitter alarm in/out.
This enables the functionality that the complete transceiver (both receiver and transmitter
unit) will enter into alarm state if one of the units fails. This is useful if the complete
transceiver should be switched to a backup transceiver.
 The RS485 serial lines from both units are connected in parallel.
This is useful to have only one connection point for the RS485 on the transceiver for remote
control.