| 摘要 |
<p>PURPOSE:To economically transmit abnormality such as the squelch alarm activation of its own station or the like to a counter station without increasing transmission capacity by interrupting a transmission base band signal as well by a low-priced circuit when the squelch alarm is raised by the reduction of a reception input electric field. CONSTITUTION:Radio transmitters-receivers 1 and 2 are respectively composed of squelch alarm activation parts 5, transmission parts 6 and reception parts 7. when the squelch alarm is raised at the radio transmitter-receiver 1, for example, the output of the reception base band signal from the radio transmitter-receiver 1 to an A-block bus-shaped LAN 3 is interrupted. Further, signal transmission from the radio transmitter-receiver 1 to the radio transmitter-receiver 2 is stopped as well and any data is not outputted all from the radio transmitter/receiver 2 to a B-block bus-shaped LAN 4 as well. As a result, at the B-block bus-shaped LAN 4, it can be detected that there is abnormality in the signal transmission in one direction at least between the radio transmitters-receivers 1 and 2, and the B-block bus-shaped LAN 4 can be prevented from being made abnormal.</p> |
