Service channel
Error – Error indicator (red); if the ERROR LED is steadily ON, it means that
the FPGA circuit could not download its operational code. Its blinking status
indicates that other initialization error happened.
Loop – Loop back indicator (yellow); this LED lights up when the device is
turned into loop back mode.
Speak – Voice channel status indicator (green); when this LED is turned ON the
voice channel between the local and remote equipment is UP. When it blinks it
indicates that call initiation from the remote site is in progress.
