I have Siemens 400-H redundant station installed at one of our location with each CPU equipped with CP443-1 for modbus TCP communication. The network is configured in such a way that only one CP is sending data to OPC server. In case of failure of one CP, other CP becomes active and process the modbus data through it. Is there is any possibility that both CPs that have already different IPs on network can process / communicate with OPC simultaneously. If yes what configuration modification is required. Actually we need the data on OPC through both CPs.

Thanks in advance for your feedback and support

Dear Kaulquappe,

Thanks for your reply. I am not able to understand what you have proposed. 

My current PLC program is using MODB4H library for this communication. Moreover, I have that part number of CP 443-1 (6GK7 443-1EX20-0XE0)) which do not allows multiple client on port 502.

I also read the manual S7WFPFDB (Simatic Modbus TCP/TCP) for CP443-1.  As per my case scenario where S7 is server (slave) and OPC is Client (Master) I think that double sided redundancy (p#65- refer attached snapshot) should work for me. 

However I have following question that is still not clear to me

1. I am not able to find MODB4H manual. How I can configure it for double sided redundancy?

2. Already configured program has 400-H station with each having one CP 443-1. Each pair is running while other is on standby. Can I be able to configure it for double sided redundancy through MODB4H. If yes do I need any new license for that or existing license can work for me?

Regards

Waqas Khalid

Thanks for the reply. One more question.

Since PLC is currently running the process at one plant and I am not in position to change the library / license at this stage. In my PG I don't have the MODB4H library, however I have original PLC application file. As you mentioned that MODB4H cannot function has hot standby so another way around that I found in documentation to configure CP for double sided redundancy so single active CP44301 may be able to communicate with two OPC at same time.

1.Can I do the modification in parameter DB of CP 443-1 and also hardware configuration changes for CP 443-1 (Addition of one more port- 503 for double sided redundancy)

2. Is there any chance that doing this modification can impact currently ruining license of CP443-1?

Thanks in advance for support

Hello,

I am in a phase of replacing hardware and license since you already mentioned that MODB4H will not let more than one connection and I have tested the same.

I have a question that If I use the library SIMATIC Modbus/TCP CP RED for S7-400 H systems (6GK7443-1EX30-0XE0) along with CP443-1 qty=2 (EX30) in 400H system which is acting as server, will hot standby work. I mean that I have two OPC client that are polling data from 400H system and I need the data to be communicated on both parts. Will I be able to poll the data on both the paths?

Really appreciated your support.

Regards 

Waqas Khalid

New question published by WaqasKhalid is split to a separate thread with the subject Once I upgraded the 400H system with new model of MODBUS CPs, it means I will not be able to revert back?.

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