### Install OPC Server Custom Device Type Extension Files

It is possible to create custom device type definitions for OPC in PME.

To recreate OPC Server custom device type extension files:

1. In Windows Explorer, navigate to `...\system\IONServices\DefaultMeasurementsExt\`.
2. Compare the target default XML files to the source files in the `CM Migration Files` folder.
3. Copy the custom device type definition XML files that you want to include to the new system.