| 摘要 |
A controller circuit enables remote control of conventional answering machines from any telephone coupled to the same telephone line to which the answering machine is coupled, and within the same dwelling (such a telephone herein sometimes called a "local remote-control" telephone). The controller in a first mode of operation is transparent to the answering machine and to the normal operation of the local remote-control telephone. When activated by a DTMF security code transmitted from the local remote-control telephone, the controller enters a second (local remote-control) mode of operation which causes the answering machine to pick up the line as if answering a call. DTMF signals transmitted by the local remote-control telephone are coupled by the controller to the answering machine for enabling remote control operation of the machine (e.g., to retrieve recorded messages). The controller prevents supervisory tones and audio messages from a Central Office, while the local remote-control telephone is off-hook retrieving messages from the answering machine, from interfering with the retrieved messages being heard through the local remote-control telephone. A version of the controller may be embodied within an improved telephone answering machine to provide local remote-control capabilities.
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