a communications system connected to a telephone network includes a facsimile machine and a telephone set . the telephone set includes a telephone for conducting voice communications over the telephone network and a telephone answering machine for automatically responding to calls received by the telephone set over the telephone network . one or more operational parameters of the answering machine are set to define how it automatically responds to calls . a switch connects either the facsimile machine or the telephone set to a telephone network . one or more operational parameters of the answering machine is initially detected and stored . a controller controls the switch to connect either the facsimile machine or the telephone set to a telephone network based on a comparison of the stored parameter and subsequently detected operational parameter detected when the answering machine responds to a call .