CP 343-1 v1.3.1. does not allow access to CPU from port 4-X1 but OK from 4-X2

[AlfredoQuintero]

Hi. This is as nerdy as it can get for Siemens experts for whom I can be grateful for advice.
Our Profibus testing systems consist of an S7-313C-2 DP with a CP 343-1 connected through the back plane.
I can get the TIA portal communicating normally with the processor if I use port 4-X2, but not with 4-X1.
This Windows 10 workstation has two NICs. For example, the S7-1516 shown under the first interface on the left works fine with this NIC setting.
As well, the CP 343-1's web server is accessible.
This has been bugging me for years but I did not do anything about it because it works with the Profinet port and with MPI-USB interface.
Tried different things on the configuration of the CP 343-1. The firmware versions are the last Siemens released.
But I would like to use the company's LAN to monitor and program this PLC, thus would like to fix this. OK, thanks for reading.

 

[JesperMP]

In STEP7 Classic, I would add a PG/PC Station to the project.
Then set it up so it is networked to the same network as the 4X1 port.
This would then provide the routing information for STEP7 to connect to the CPU via the CP343-1.
Not sure how to do that with TIA.
Not sure that it is even necessary when the routing is within the same rack as the CPU.

Other than that, the usual suspects. In the company network there is probably a router connecting the CP343-1. Is the Routers IP set in the hardware configuration of the CP343-1 ?

You can open the webbrowser of the CP343-1, can you also ping the CP343-1 ?


Instead of using accessible node, try to go online directly, and be sure to select "device with same address". Check that TIA selects the right interface and IP address.

 

[AlfredoQuintero]

Thanks very much for your comments.

You can open the webbrowser of the CP343-1, can you also ping the CP343-1 ?

Well, yes, as shown in the graphic capture.

Instead of using accessible node, try to go online directly, and be sure to select "device with same address". Check that TIA selects the right interface and IP address.

I tried and when selecting the NIC of the company/s LAN the S7-313 is not detected. I know the company LAN is not an issue. There is no routing. And when programming our S7-1516 I use the equivalent interface (not the Profinet interface) and with the S7-1516 TIA can access and program the PLC.

 

[JesperMP]

I dont see a capture of PING.

I know the company LAN is not an issue. There is no routing.

So the company LAN is all in the same subnet ?
Just trying to understand what you have.
edit: And try to describe the company LAN a bit more. If it is an extensive network, duplicate addresses can easily happen if someone attaches a new device somewhere.


It is worrying that the CP343-1 does not appear at all in the accessible nodes of the company LAN.
Try to remove the company LAN from the X1 port, and connect the PC directly.

And I would still try with another PC, no matter that you can reach the S7-1516 from TIA.
I suggest use Proneta on the other PC.

 

[PLCDontUQuitOnMe]

On a CP343, X1 and X2 can be set up on different networks.


Have you tried setting your laptop to the same subnet as the X1 gigabit port and plugging in and trying to ping it? If so what happens?



IE: X1 IP address is 192.168.001.246, set laptop to 192.168.001.250 and try to ping 192.168.001.246 after plugging in directly to the port?

 

[AlfredoQuintero]

The company LAN is simple. All nodes are on the same subnet with only a few dozen nodes. It is possible to ping the CP343-1 and access the web server, as shown again the capture below.
It seems to be an issue with this version of the CP343-1. Apparently it does not respond to the DCP Command "Identity Request all", to which other devices do respond, including an S7-1516, as shown below:
Edit: I must point out that the CP343-1 works as expected on the "other" port, i.e. the port that support Profinet. The screenshot at on the original post was taken when the TIA portal was connected to the other port and using a different NIC.

 

[JesperMP]

Subnet mask on the CP343-1's X1 port is 255.0.0.0.
Is that intentional ?

I would really like to see a Proneta scan of the entire network.
And I would really like to see you try with only 1 PC connected directly to the GBIT port.

I had something similar not so long ago, and it turned out that a PC was setup with an additional IP address by mistake, conflicting with one of the PLCs IP addresses. It made the PLC unreachable. I found out with the use of Proneta.

 

[AlfredoQuintero]

Yes, the subnet is 255.0.0.0 not only for the CP343-1, but for the S7-1516 and all the rest of the nodes in that network. So, yes, it is intentional

The Proneta scan shows the nodes that respond to the DCP Identity Request All that I show in the Wireshark. I do not want to show the Proneta scan on the company network. The problem is that the CP343-1 does not respond to the broadcast request for DCP Identity Request All.

Thanks for the responses. I will leave it as it is. I can program this P+LC using the other port of the CP343-1.

 

[JesperMP]

I would still try these 2 tests:
1. Isolate the PLC from the company network. Connect the TIA PC directly to the PLC.
2. Same as 1. but change the PC.