Add reauthentication

Reauthentication can be used to implement an additional security query before writing a variable. This prevents someone without the appropriate rights from writing. This functionality is also available without an Audit Trail.

Enable reauthentication on a symbol in Visual Studio / TcXaeShell

1. Open the TwinCAT HMI Configuration window.

2. Go to the Server Symbols / Mapped Symbols tab.

3. Activate the checkmark under the Reauthentication Required column.

All symbols with the checkmark set require reauthentication in order to write the value.

Activate reauthentication via the server configuration page

1. Open the server configuration page.

2. Go to the TcHmiSrv / Symbol mappings tab.

3. Go to Symbol mappings.

All currently mapped symbols are displayed here.

4. Select the symbol you want to change.

5. Go to the Reauthentication required entry.

6. Check the box on the right side.

7. Now select true to activate or false to deactivate.

The symbols you have configured now require reauthentication before the write command can be executed.