Black Box Compact T1 MT850A User Manual page 403

LEDs
Each FXS port has a corresponding LED, described in the table below. This chart
applies to all the FXS service cards.
Compact T1 - Release 6.1
State Loop Start
Meaning
Off N/A
Green Idle
Red N/A
Yellow Call in progress
Flashing green Ringing
FXS Voice Card
Ground Start Meaning
Idle (tip open)
Tip ground (incoming seizure)
Ring ground (outgoing seizure)
Call in progress
Ringing
LEDs
8-9