| 摘要 |
<p>A transceiver unit employing a time sharable circuit for performing two functions, the first of the functions operable during the send mode of the transceiver, the next function operable during the receive mode of the transceiver. In the send mode, the circuit responds to a proper receiver ready signal to activate the transmission. By proper filtering the circuit distinguishes over noise. In the receive mode, the circuit responds to the initial portion of the transmitting signal for determining the proper receiver speed. The circuit includes a filter, a voltage window detector responsive to a frequency band represented by a voltage range, and two detection circuits. The first detection circuit is provided with delay time sufficient to insure receipt of a valid ready signal when in the send mode and a lesser delay time to assure a valid receipt of a transmitted speed select signal when in the receive-speed select mode. A second detection circuit is gated from the voltage window detector to detect a different speed select signal transmission indicating a different speed. Logic circuitry is coupled to the decoded speed indicating signals as a means of further decoding, interpreting and determining transmitted speed information in the unit.</p> |
