AbuSuhail

What type of trunks your pbx is equipped with?
Normally, analog CO lines require Polarity Reversal for trunk to trunk connection feature,and the same P.R is needed to disconnect the call upon completion. If no P.R. the call will be held till manually released.

glearned

Good day: I would like to know exactly how the NEC detects the disconnect? Is the NEC actually looking for a reverse battery condition to go away or, does it detect a change in line current that occurs when the line polarity reverses? The reason for my question is that I have lines that provide an interruption of the line current (opens up the line briefly) when the far end disconnects instead of reversing the battery. If the NEC Aspire is actually detecting a change in current, then the disconnect supervision should work fine with the open circuit method of far end disconnect.
Thanks Jerry

negromo

About the stucked in tandem connections, The Neax 7400 (an 8 years old model, dont know the equivalent model in USA) can release te connection in analogue trunk tandem in a timeout condition. I can search the command in the manual if you need.

Peace.

shy

NEC Aspire works perfectly to release analogue lines in Tandem Trunking, for this you need to enable Busy Tone detection on lines and enter the right busy tone cycle values.