AT&T Synapse User Manual page 294

Symptom
For OHP equipment connected to the AUX OUT jack, this Troubleshooting refers to the ATA front-panel AUX OUT LED. This
describes the behavior of these LEDs:
OFF: There is a problem with the WebUI configuration for OHP. Either Paging is disabled, or the selected Paging Port is
not AUX OUT.
RED: Although the WebUI supports OHP, no connection is detected.
Steady GREEN: A cable is connected to the AUX OUT jack.
Flashing GREEN: An OHP is in progress.
We also use these LEDs to help diagnose problems.
Troubleshooting
Synapse User's Guide
Probable Cause
Single-Zone OHP Connected to AUX OUT Jack
Corrective Action
294
ATA OHP Troubleshooting