I have a request from an intercom company to provide some type of tone upon disconnect from the PBX. This is on an analog port connected to an intercom system with an outdoor speaker at a hotel. Currently they receive silence upon disconnect. System option for last calling party dial tone is enabled, but still just silence. I was looking at intercom mode, but I can't find a description of that COS option (278). Any help would be helpful.!

Check out Sandman. I had this situation several years ago and I remember getting a device from them that worked. There's nothing in the Mitel that will provide tone on disconnect. You can provide a disconnect and a return to dial tone to the last party to stay up in the call.

Rcaman

"You can provide a disconnect and a return to dial tone to the last party to stay up in the call.".
Not sure what you mean- the Sandman device does that? What is last party clear with dialtone in the Mitel?

Thanks!