Connecting A Radio - semaphore KINGFISHER PLUS+ Hardware Reference Manual

Ligne de Télécommunication Cordon
Pour réduire les risques d'incendie, utilisez seulement du câble d'une

6.8.2 Connecting a Radio

As the port is isolated it is necessary to use an external voltage source (normally from the
RTU 'radio' connection +12 V) to power not only the radio but also the carrier detect circuit.
Some radios have a very low audio interface level (TX Audio), e.g. Maxon DM 0530,
DM-2850, SD-125 and Tait T2010 / 2015. These radios will most likely require a resistor
network external to the port to drop the TX Audio level.
Some radios (e.g. Maxon) have an internal pull up resistor to +5 V on the carrier detect line,
if +12 V is used on the carrier detect optocoupler and then run to the carrier detect output on
the radio, the optocoupler will always be driven. There are several ways to get around this:
1. Use a radio without an internal pull up to +5 V (Trio SR, possibly Tait).
2. Modify the radio by removing the internal pull up, as per manufacturer's instructions.
3. Use +5 V to supply the carrier detect optoisolation circuit. (DO NOT USE +5 V FROM
THE BACKPLANE CONNECTOR AS IT IS NOT ISOLATED).
Hardware Manual Version 7.16
section minimale de 0.13 mm² (26 AWG) pour les connections de
Line / Radio Option Board Interface
http://www.servelec-semaphore.com/
Kingfisher Plus+ Hardware Manual
télécommunications.
Page 108