I have a Valcom VIP-801A in use in that exact same situation. Been in place for a few years and works great. Easy to setup.
Valcom VIP-801A

Been a while since I was there, but if I remember correctly, the PGD outputs to the Valcom unit. Users can press the page key on their phone, then enter either 1 or 2 for the zone (building).

There is a unit at each building.

Jim

Last edited by Yoda; 03/17/20 03:33 PM.