Error communicating Simatic Manager to S7-400

[gmueller]

Let me preface this post by saying I am a total rookie/newbie in the PLC arena, so please forgive the lack of knowledge and/or use of correct terminology.

The issue: We have a laptop we use on our production line for troubleshooting and maintenance. The on-board network port was damaged and stopped working so I installed a USB network interface. I can ping the PLC and various modules. I can communicate with the AB equipment we have. I changed the interface via the 'Set PC/PG Interface' menu. The new NIC seems to work fine with everything except we cannot go online with a project in Simatic Manager. Whenever I try I get an error: "Online: Connection could not be established. The connection partner is not responding." It worked just fine on the old internal network port. I don't know where to go from here.

Any suggestions would be greatly appreciated.

Thanks,
Gary

 

[mk42]

If you can ping it, then you probably already have an acceptable (probably static) IP address set. That's the most common thing I see missed.

You might need to disable wireless on the laptop. I've seen that sometimes even when the PG/PC interface is correctly set, Windows sends the data from Step7 out the wrong interface, because the wireless card has a higher internal priority.

 

[gmueller]

Thanks for the response mk.

Yes, the ip is static. I had already disabled both the wireless and non-working onboard NIC but saw no change.

 

[mk42]

Then, as much of a copout as it may be, has rebooting helped?

Oh, you said you had the correct PG/PC setting selected. What did you choose?

 

[gmueller]

Yes, I tried many reboots with no luck.

After disabling the wireless and on-board port, the only choice I had in PG/PC was the USB port. There were 3 versions I think (I'm not in front of it at the moment). ISO, TCP/IP, TCP/IP(Auto). I tried all 3 but couldn't connect with any of them.

 

[mk42]

So far, it sounds like you're doing the right things. Not sure if that helps much....

TCP/IP is the one that I typically use.
TCP/IP (auto) doesn't allow you to route to devices in a different subnet, but can automatically give you a new IP address to move you to the local subnet if needed. This really only matters if you are trying to connect to a PLC via a VPN tunnel or something like that.
I'm not sure what the use case for ISO is; I've never needed it. Maybe it works too, I couldn't say.

You said S7-400 in the thread title. Are you trying to communicate to a built in port, or one of the CP cards?

It's also possible that a firewall or something is getting in the way. Simatic Manager uses port 102 to communicate/download to the PLC. One way to test if that port is available is with telnet. If you try to telnet into the PLC using port 102, it should go to a blank screen where it doesn't allow you to do anything. It doesn't accept any commands or logins, and the only thing you can do is close the command window. If you get the blank screen, it worked. If you get anything else, like an error, but can still ping the same IP, then either the IP is wrong, or the port is blocked.

In Windows XP, telnet is built in; the command would be "telnet 192.168.0.1 102" with your PLC's IP address instead. In Win 7, it isn't installed by default, but I think you can download it.

 

[gmueller]

I will have to verify whether it is the built in port or a CP card.

As for the laptop, it is Windows XP and the firewall is disabled. I tried connecting via telnet as you suggested but it failed to connect. Not sure why that port would be blocked now. Nothing has changed except the network interface. ???

 

[PreLC]

I have the same issue. Any solutions in 2022?