Hi all,

I am facing an issue about the connection between WINCC and PLC redundancy system.

The system includes 01 PC server with WINCC V8 and 02 PLC S7-1517H v3.1 that set the redundancy. The system configuration is picture below:

PLC redundancy system: 2 PLCs are synchronized via fiber optic cable (orange line) and connect each other via port XP1 (black line). 

PC Server connects to PLC redundancy system by system IP 192.168.1.100.

The issue is that:

• PLC1 was primary, PLC2 was backup. When I stopped the PLC1 by a hard switch on PLC1, PLC2 switched to primary immediately, but PC server lose connection to PLC redundancy system around 10 second, after that could connect again. I also ping system IP 192.168.1.100 from PC server that time, it could ping continuously, not interrupt.
• After that, I started the PLC1 again by a hard switch on PLC1, PLC2 still was primary, PLC1 was backup. During the PLC1 was starting, PC server lose connection to PLC redundancy system around 10 second, after that could connect again. I also ping system IP 192.168.1.100 from PC server that time, it could ping continuously, not interrupt.

Why did the connection between PC Server and PLC redundancy system loose during change over?

Is there any way to resolve it?

Hi itafusna,

Thank you for your support

I would like to reply as below:

- Try configuring the "TCPIP.1" option (without <Auto>) in the "Set PG/PC Interface" tool.

=> I tried it but it did'nt work.

- Install the latest update released for both WinCC and SIMATIC NET.

=> I downloaded and install them in link when i bought licenses. So is there any impaction on licenses if I install the latest update of them?

- Eventually, use the software redundancy script instead of pointing to the system IP address

=> I want to the available function of WINCC, only setting/config. If  there is no other way, I will try it.

Hi Murof,

I use in WinCC V8 the systemIP of the S71500H. In above attached picture, I use systemIP: 192.168.1.100 in WINCCV8.