I have a KX-TA824 and am using a USB to phone interface from Parliant. The interface generally works ok. But, since I have placed the interface on a station line it no longer receives caller-ID. I am reasonably sure the problem is the difference between the station line voltage and regular POTS line voltage. On my PBX I measure ~-28v tip to ring.

I had pretty much given up getting any resolution - the vendor says their product is intended for CO lines - and then I found this forum.

So, my question is... Has anyone succeeded in finding a way to "adapt" -48v devices to work on a station line like on the 824, or "adapt" the station line to provide -48v?

Any ideas appreciated.

Richard