| 摘要 |
<p>The duplex or simplex intercomm. system, for offices and factories consists of communications stations, each with a selection button, a microphone, a loudspeaker and a control unit. Each station (A) is assigned a time slot. During this a connection can be made by the speak switch (HSA) via an AF bus (TEL) that connects with the microphones and loudspeakers (LA) and over a listen switch (HSA) to the other station. The repetition frequency of these time slots is chosen to equal the upper frequency limit of the frequency band of the signals being transmitted.</p> |
