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gui2:sermux

Serial Mux

The Serial Mux mode is used to connect one modbus master serial port to a modbus slave COM port. This mode can be used to access internal registers by using the terminal as an RTU. 

A connection between a master serial port and a slave COM port and internal registers is configured using a row in the form. The connection is enabled using the first check box. Access to the operational_overview is enabled using the second check box.

Src Port Master serial port number in the range 0 to 1.
Dst Port Slave COM port number in the range 0 to 4.
RTU ID Modbus address in the range 0..247. If 0 the message is broadcast.

Example #1: Serial Master

In the diagram a modbus serial master is connected to a PLC which is the modbus serial slave.

Example #2: Serial Master with Modbus RTU

In the diagram the modbus serial master can access the PLC modbus slave and the terminal internal registers. The RTU ID on the form is set to 2 and enabled using the check box. Modbus request messages received by the terminal with an RTU ID that is not 2 are sent to the serial slave. If the RTU ID is 1 then the serial slave returns a response. Modbus request messages received by the terminal with an RTU ID that is 2 are used to access internal registers.

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gui2/sermux.txt · Last modified: 2020/04/13 08:50 by dmeier