JPS63158041U - - Google Patents

Description

[Brief explanation of drawings]

FIG. 1 is a block diagram illustrating the configuration of a communication signal line switching circuit showing one embodiment of this invention, and FIG.
The figure is a flowchart explaining the communication line switching control operation procedure according to this invention, Figures 3a and b are block diagrams explaining the analog input processing operation of the microcomputer shown in Figure 1, and Figure 4 is a conventional communication line switching control operation procedure. FIG. 2 is a block diagram illustrating the configuration of a network. In the figure, 1 and 2 are nodes, 3 is a connector, 4 and 7
is a multiplexer, 5a and 5b are photocouplers,
6a is a driver, 6b is a receiver, and 8 is a CPU.

Claims (1)

[Scope of utility model registration request] In a communication signal line switching circuit for a communication network system in which devices each having a communication interface for mutually communicating predetermined data from a host are serially connected via a predetermined communication line, an external device for mutually transferring desired data, a connector for connecting the external device to the communication line, and a line switching means for mutually switching between the external communication line connected to the connector and the communication line; and timing control means for monitoring the connection state of external devices to the connector and controlling the switching timing between the communication line and the external communication line by the line switching means based on the communication state of each of the devices. Features a communication signal line switching circuit.