CP 443-1 communicating problem with OPC server (top server) / modscan

Plz see the attached rough schematic of required architecture.

Regards

Waqas khalid

DearKaulquappe,

Thanks for your reply.

You mentioned that 'You need to parameterize a second connection in 'NetPro'. Please see the already configured netpro. As per my understanding all the connections are already configured. As you know that CP 443-1 has two ports which as per my understanding acts like a switch and in net pro there is only one 'PN-IO' connection which is already configured with IP address. Please see  attached snapshot.

Do you mean that I need to configured each port of CP 443-1 separately. If yes, please guide me how to do it.

Moreover, as I mentioned earlier that the respective redundant CPs already polling the data to respective OPC servers (top server) as showed in my last post snapshot. Only problem is coming that when I try to poll the same modbus data from CP 443-1 on modscan/ other OPC server on same IP.

For example in my case configured IP of one of CP 443-1 is 192.168.188.53. One EWS (Engineering workstation) with OPC server installed already polling data from this IP. Since protocol is Modbus TCP, so if any other Modbus TCP server like modscan or top server connected on same network configure to poll the data from same IP, principally it should communicate without any further configuration. Please correct me if my understanding is wrong.

What additional configuration I would required.

Please accept my apology for long emails, but I am trying to explain the problem I am facing.

Regards

Waqas Khalid

Hi,

As was already asked, what specific version of Modbus library do you use, and what CP card do you use?

Do you use the Modbus/TCP CP Redundant (Article number: 6AV6676-6MB30-3AX0)?

If so, the look at:

Which technical data applies for the SIMATIC Modbus/TCP blocks and for which CPUs and CPs is it released?

A Modbus TCP server listens on a port (default is port 502). So the client you have probably connects to this port.

It is possible for the Modbus/TCP library to accepts connections from specific a clientson a specific port, or from any client. If it currently accepts connections from only the one client on port 502, you will never get another client to connect to port 503 for example. Or you can set up the server to accept connections fro any client/multiple clients on port 502 (if the CP card supports it. See link above about multiple clients).

Read the documentation from the Modbus Library about the connection setup.

Dear Michael and Kaul Quappe,

Really appreciate your suport.

I think I got the answer that why I am not able to poll the data from CP 443-1 on new device.

Actually I am using CP 443-1 Order Number = 6GK7 443-1EX20-0XE0 V 2.1 in s7-400 H application.

In my application CP 443-1 is configured in server configuration on TCP port 502. As per the

Siemens article: How do you configure a connection with the multiple port 502 for the Modbus/TCP function block MB_REDSV? 

Older CPs 443-1 version for use in an S7-400 H station permitted only 1 connection at port 502.

If you want to communicate with more than one connection then you need to select specific different order number for same CP as mentioned in below table:

Since in my application one client i.e. OPC server (top server) is already communicating, so CP-443-1 which has limitation to connect with one client only is not allowing any second device to communicate on same 502 port. Same thing is also explained in  section 1.2

Programming manual of "SIMATIC Modbus/TCP communication using CP 343-1 and CP 443-1"

Regards

Waqas Khalid

New question published by Syed! is split to a separate thread with the subject Port address for multiple connections Modbus using CP 443-1.

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