we have 2 transtalk 9040 sets working off of a dual radio module. both of the sets have been mapped to different channels. both sets cherp and continue to cherp after the call is answered by another partner system phone. if the call is answered by one of the transtalks, then the cherping continues on the other transtalk. to stop the cherping, we have to go to the transtalk that is cherping & turn it on & off.