KX-TA824 - KX-T7731 How to go off-hook in Intercom mode

[Switchroom]

I'm installing an 824 in a Day Care Center that had an old 308 I put in years ago. With the 308 the main PT phone had a SLT jack in the rear, where they used a non-proprietary cordless phone and could unlock the front door for parents that pushed the button on the KX-T30865 door phone. The 7731 doesn't have a jack, so I've selected "parallel telephone" in Extensions/Main and put a splitter on the jack, one side to the 7731, the other to the cordless. When the doorphone button is pressed, the cordless can answer the doorphone, but can't unlock the door (the SLTs can by flashing and pressing 55).

With the splitter, when either the 7731 or cordless goes off-hook they immediately select a CO line, meaning the cordless can't open the door even if they hung up from the doorphone call. If I disconnect the 7731, when the cordless goes off-hook it's got intercom dialtone like the other SLTs. Is there a way to get the PT to go off-hook in intercom mode? Hopefully that would let the cordless on the splitter with it be in intercom mode also.

 

[obtsystems]

It should behave the same. Have you tried the cordless in as an slt Only port. Could be the flash timer

Out of curiosity did you try 5 on its own because it is parallel with key phone

 

[Switchroom]

The setup is Jacks 1 through 5 are intercom only (no CO access) and in classrooms. They can also unlock the door.

Jacks 6 and 8 are SLTs in offices that can answer COs, dial out and unlock the door.

Jack 7 is the 7731 at the front desk, and I was hoping to duplicate the 308 with its older PT (don't have the model # right now) that had a SLT jack in the back. I did manage to get the PT to go off-hook in intercom mode (Program->11->Store), which was the way the 308 was set up.

As mentioned, when the PT 7731 is disconnected from the splitter so Jack #7 becomes SLT only the cordless works. I did notice the SLTs on any Jack would open the door relay by only pressing 5 after flashing when in a doorphone call.

Looks like my only option is to buy a KX-TA82483 3X8 expansion card and give the front desk cordless it's own jack.