I have an S7-1500 and a PC system in my project. I have been working on this project for weeks and it has been fine. Various data coming in and showing as a pie chart on a screen. 

I then updated the firmware of the PLC from 2.6 to 2.9 and now whatever I do I cant seem to establish a connection between them. 

My runtime starts up and runs fine. The password is correct. The HMI connection is set up in the devices and networks. The S7ONLINE is setup the same as it was on the PC system.

Can anyone suggest what I may be missing? Its driving me mad!

Hi aqueousdan,

Surely what is indicated in the following FAQ is happening:

Why is it not possible to establish a communication to a S7-1500 CPU with firmware V2.9 with the WinCC Unified Comfort Panel with TIA Portal V17 or higher?