Tech Logic VoiceLink II User Manual page 6

Infrared Dome Sensor (ICS-50)
Dome Sensor is the receiving component mounted
on the ceiling that collects the modulated infrared
signal from the transmitter (Pendant, Handheld, or
Body-Pack). The composite signal is sent to the
receiver input via a dual shielded cable. The sensor
has 30 receiving diodes providing 360 spherical
reception.
Power "ON" LED (Green) indicates that the
sensor is receiving power from the receiver.
Cable (50') connects the sensor to the receiver. The
cable is dual shielded with RCA connectors on each
end and is plenum rated.