We would need more details about what exactly you are trying to do in order to try and help.
You can contact us at the email below with some details to start a discussion. We would also recommend you contact the manufacturer of the PROFINET device as well.
What is the PROFINET device you are communicating with?
What parameter data are you wishing to read / write? Manufacturer or PROFINET specific info?
Is it cyclic or acyclic data that you wish to read/write?
Are you using profiles (PROFIdrive, PROFIsafe, etc.)
Is another PLC / PC based IO Controller talking to the device simultaneously or just the PC?
Is the PC controlling the device with a user application or just acting like a programming tool or IO supervisory function?