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Serial Mux

The Serial Mux mode is used to connect one or more master serial ports to a slave serial port.

Serial Mux

The slave can also be connected to one or more master IP ports using the IP Mux mode.

The Serial Mux mode can be used to access Internal Registers if the src port is associated with an RTU ID and modbus protocol is used.

A connection is configured by a row in the form that has parameters and check boxes. The first check box needs to be checked for the connection to be enabled. The second check box needs to be checked to enable modbus access to Internal Registers.

The configuration parameters are:

Src Port Master serial port number in the range 0 to 4.
Dst Port Slave serial port number in the range 0 to 4.
Msg Type Type of messages. The most common message types are supported: Modbus, DF1, and ROC. If Modbus/ROC is selected then the source port messages can be Modbus or ROC or both intermixed. If DF1 is selected the source port messages can only be DF1 HALF DUPLEX.
Internal RTU Address Modbus RTU address used to access the IP100s internal registers.

Example #1: Modbus Serial Masters

In the diagram the two SCADA Host computers are the modbus serial masters and the PLC is the modbus serial slave.

Modbus Serial Masters

Example #2: Modbus Serial Masters with Modbus RTU

In the diagram the two SCADA Host computers are the modbus serial masters that can access the PLC modbus slave and the IP100 Internal Registers. The RTU ID on the form is set to 2 and enabled using the check box. Modbus request messages received by the IP100 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 IP100 with an RTU ID that is 2 are used to access Internal Registers.

 Modbus Serial Masters with Modbus RTU

sermux.txt · Last modified: 2023/08/29 12:50 by