TRANSMISSION LINE ACQUISITION CONTROL SYSTEM

摘要

PURPOSE:To realize a semi-duplex transmssion system with a few number of lines by transmitting and receiving a transmission line acquisition request signal and a transmission line acquisition permitting signal through two signal lines. CONSTITUTION:In transmitting a signal from a CPU1 to a CPU2, a data linkage adaptor CLA3 transmits the transmission line acquisition request signal X to an opposite side adaptor CLA'3' through a signal line 41. The CLA'3' transmits the transmission line acquisition permitting signal Y through a signal line 42 on the condition that a reception request is generated. When a signal Y is not obtained within a prescribed time after the transmission of the signal X, the CLA3 generates an error signal. When the CLA3 receives the signal X from the CLA'3' during the generation of the signal X, the CLA3 transmits the signal Y to the CLA'3' on the condition that the reception request is generated. This is applied to the transmission line acquisition control to transmit signal from the CPU2 to the CPU1.