| 摘要 |
PURPOSE:To surely detect the occurrence of a faulty state between equipments by sending a dummy data when a prescribed time elapses after a transmission data is sent to other equipment and regarding it as the occurrence of down-state if no reply comes from other equipment to the dummy data. CONSTITUTION:When a data processing means 1 outputs a data f processing request, the data is sent to other data processing means via a transmission control means 2 and a transmission line 3. In such case, a supervisory means 4 activates a timer or the like from the point of time to start the supervision of a prescribed elapsed time. When a prescribed time elapses, a dummy data such as its own device number is generated to a dummy data generating means 5 and sent to other data processing means via the transmission control means 2 and the transmission line 3. While no response data such as an ACK is sent from other data processing means, a down state signal output means 6 outputs a signal representing the occurrence of the down state to apply corresponding processing. |
