The TC5+ is a remote monitoring system previously manufactured to test the correct working of all installed equipments inside of a TV repeater room situated on the top of a mountain. It can be also used for several other applications.
The TC5+ is composed by a transmitter and a receiver equipment.
The system send DTMF bi-tone information on the audio line and it allows to test from remote the status of:

transmitter front panel

The 5 led starting up meets the 5 relays that will close all clamps output situated on the receiver back panel.
When the energy on the transmitter is faulty, the receiver will indicate it by switching on the power down led and closing the relay on 1 and 2 connectors pin with 4 contacts situated on the back panel.
After about 30 sec. the transmitter stops to send DTMF data and all receiver leds will be flashing.
When the temperature sensor of the transmitter shows that the environmental temperature is out of the set up range, the alarm will be sent to the receiver, so the OVER RANGE TEMP will be lighted and the relay will be closed on the 3 and 4 pin of the 4 contacts round connector situated on the back panel.
It's possible to put the audio output of several receiver into a loop state, taking care that each single receiver has been placed to an identification address, different from the other ones.
Both the transmitter and the receiver supply is of 220 Vac.