I had a working and tested HMI that just stopped communicating. Looked all over for logical solution.
What worked:
Use SerialDF1forSLCMicroCom1 default settings seem to work
This makes no sense, but it looks like the lights and switches can become disconnected from the driver
Fix was to:
add a second driver (any driver you are going to remove again)
remove existing driver
add the existing driver back
remove the second driver
set ComComponent for each component back to the original driver
So basically no change, except now it works.