Changing the function code of a data item of a Modbus RTU server
The selected function code determines:
- whether the data item is read or written to,
- the size of the data item,
- whether the value of the data item can be set by an application program or is provided externally (e.g. by an I/O system).
- Prerequisite
- You must add a data item to the Modbus RTU server.
- Open the device view.
- In the device tree, double-click the server whose data item you want to edit.
- Select the data item you want to change.
- Double-click the Function code list box.
- In the drop-down list, select the new function code.
- Press Enter.