Abstract: When a standard business office communication system is combined with ACD features, it is necessary to design the system to accommodate a variety of operational modes. Two such modes are handset operation, where a station user talks and listens via a conventional hand-held instrument, and headset operation where the user has an earphone and mouthpiece supported by the head. In headset operation, the station is made to appear off-hook permanently and incoming calls are signaled by a short burst of audio tone followed by an automatic connection to the called party. In handset operation, ringing signals must be applied to the station, and these signals continue until the incoming call is answered by a subsequent off-hook condition of the station. The disclosed arrangement allows each station to operate in either mode on a per call basis.