| 摘要 |
PURPOSE:To attain ease of retrieval of a failed equipment by interlocking a switch connecting a transmission line of a bus type data transmission system and a transmission/reception circuit with an on-line/off-line mode selecting switch so as to attain respectively electric connection/disconnection. CONSTITUTION:Data transmission lines 1, 2 and 3 are connected by a single transmission line 4 and transmit/receive data mutually. The transmission line 4 is terminated at a termination resistor. Each data transmission equipment consists of a connecting terminal 20 to the transmission line 4, a relay 21 inserted between the terminal 20 and transmission and reception circuits 22, 23 and conducting connection/disconnection for the transmission line 4 and the transmission/receptoin circuits 22, 23 a logical section 24 controlling transmission of data and processing of reception data between the transmission/reception circuits 22, 23, and a mode setting switch 25 setting the operation of the on-line mode or the off-line mode for the data transmission equipment. The relay 21 is interlocked with a mode setting switch 25 opening/closing the contact. |
