Can the 50 do trunk to trunk and let the station or console out of the call? It works if the station or console stay as a party to the call but as soon as the station or console hangs up the trunks disconnect. BTW the 50 has MCII and MS55.
Command 100, Register 05, Bit "C" (CO to CO Connection) needs to be set to a "1".
It sounds like you're already able to set up a conference, so check this setting that allows the 2 trunks (assuming COs) to stay connected.
I believe you also need in the cos of the person tandeming the trunks their cos register "j" as a "1"
Well... I'm missing something. Checked all the bits that fifty5 and panda mentioned, they were already set. Still can't connect 2 trunks and have the station that set up the conference hangup without the trunks disconnecting.
Ok.
In the trunk programming, register 1, bit "G".
Otherwise, you can get in touch with me while you're on-site, and we can go through the setup!