If you have it programmed for control channel only I think it will just display "CC" where the talk group ID would show when not in control channel mode. Also if my memory serves me right it will only do CC on 800 & 900 MHz motorola systems. I can't remember if there if a way to make the ID's show in CC mode. If not just enter all the voice channel in the same bank programmed for trunking and take it out of CC mode. Then the ID's will show for sure.