| 摘要 |
PURPOSE:To prevent the collision with other system and to utilize a frequency effectively by providing a reception frunction to detect a carrier of the same frequency as the transmission frequency, confirming the absence of the carrier within a random time after no carrier is detected to apply the transmission. CONSTITUTION:A clock signal (g) from a clock generating circuit 73 is used as a clock of a counter 72. When a data memory 4 sends a data and other system does not use the same frequency and a carrier sense request signal (b) is made active, an initial timer value (e) to a counter 72 is set by an initial timer value (time t) generating circuit 75 and the counter 72 starts counting. After the counter 72 counts the initial timer value (t), a transmission enable signal (h) is generated, an F/F71 is reset to bring the data memory 4 into the transmission enable state. When the data memory 4 receives the transmission enable signal (h), the switch 2 is thrown to the position of the transmission section 3 immediately, the transmission section 3 is set, the data stored in the data memory 4 is sent to the transmission section 3, from which the data is set in air. |
