Make PLC program routine changes

If you import a routine containing new tags to an online PLC, the Auto Synchronize Tags option will not synchronize the new tags with the Communication Driver. The Communication Driver will reject the new tags as invalid even with the Auto Synchronize Tags option enabled until the tag database is re-reset by poking a 1 to the system item $SYS$UpdateTagInfo.

As a best practice, changes of PLC program routines should be done when the PLC is offline. Changing or importing the PLC program routines when the PLC is online is not supported.