CE Device won't comm. with PLC

CE Device won't comm. with PLC

I can ping the PLC from the CE device.
I can run the app on my PC and read and write values to/from the PLC.
I CANNOT read/write values to/from the PLC from the CE app.
What am I missing.
Thanks.

This is a migrated post! Originally posted on 07.03.2009 by user scotttee. Please be aware that information can be outdated.