Which OS7000 as depending on the system/hardware you may need to get PRS hybrids for the TRK cards.

The programming is done in MMC414

There are several modes of PRS you will need to go through and figure out which mode your carrier is using.

Bunnie - PRS modes are Reversal on Idle, Reversal on Answer and another type which I can't remember.

We used them all the time on the DCS/iDCS systems when customers have AA and PSTN lines since those old AA cards never detected busy signal so customers would get calls with no-one there due to people hanging up in the AA