1

In the Devices tree, double-click a Modbus TCP slave device.

Result: Its configuration window is displayed.

2

Click the Modbus TCP Channel Configuration tab:

3

To remove a non-predefined channel, select it and click Delete.

4

To change the parameters of a channel, select the channel and click Edit.

NOTE: For the devices that provide predefined channels, only the Repetition Rate value can be modified.

5

To add a channel, click Add Channel.

This dialog box is displayed:

6

In the Channel area, you can define:

oName: optional string for naming the channel.

oUnit-ID [1..255]: unit ID ⁽¹⁾ of the Modbus TCP slave device (by default 255).

oRepetition Rate: polling interval of the Modbus request (by default 20 ms).

oComment: optional field to describe the channel.

oFunction Code: type of Modbus request:

oRead/Write Multiple Registers (Function code 23) (by default).

oRead Holding Registers (Function code 03).

oWrite Multiple Registers (Function code 16).

In the READ register area, you can define:

oOffset: starting register number to read from 0 to 65535.

oLength: number of the registers to be read (depending on the function code).

oError Handling: define the fallback value in the case of a communication interruption:

oKeep Last Value (by default) holds the last valid value.

oSetToZero resets the values to 0.

In the WRITE register area, you can define:

oOffset: starting register number to write from 0 to 65535.

oLength: number of the registers to be written (depending on the function code).

7

Click OK to validate the configuration of the channel.

8

Repeat steps 5 to 7 to create other channels that define the Modbus communication with the device. For each Modbus request, you must create a channel.

Read/write multiple registers (function code 23)

125

121

Read registers (function code 03)

125

-

Write registers (function code 16)

-

123