| 摘要 |
PURPOSE:To inform abnormality and to simulate an on-line state by counting up the number of continuous defects of transmitted and inputted data, and when the counted value reaches a fixed value, switching data transmission from the on-line to an off-line. CONSTITUTION:When a transmission circuit 1 receives data signal transmitted from a control device to a terminal 5e, the data signal is outputted to transmission lines 6a, 6b. When a result is normal, the circuit 1 outputs a normal signal to a terminal 5b and resets a counter 2, and if defective, outputs a defective signal to a terminal 5c and counts up the counter 2. These signals are transmitted to the control device through the terminals 5c, 5d. When the output of the counter 2 is compared with the output of a constant circuit 5 by a comparator 3 and both values coincide with each other, the comparator 3 turns the state of an FF4 to a setting side. Said state is transmitted to the control device and inputted to the circuit 1. When the circuit 1 receives the data signal from the control device, no signal is outputted to the transmission lines 6a, 6b and a normal signal is outputted to the terminal 5b. The FF4 continues the off-line state. |
