Error: NetLink Error Code 0x12 (12)

This error means "Master not into the logical token ring." Verify the following settings:

• In the server, click Device Properties ⇒ Communication Parameters. Then, locate the MPI ID setting. This should be set to the PLC's MPI address.
• In the NetLink Configuration Utility (which is located in the server's Utilities sub-directory and can be launched through the Start menu shortcut), locate the Own Station Address setting. This is the MPI address of the NetLink itself, and must be set to an address that is not used by the PLC or any other device on the MPI bus.
• Set the "highest station address" of the PLC (or other MPI-bus masters) greater than or equal to the Own Station Address of the NetLink Configuration Utility.

Setting these items correctly should resolve the error.