OPC with multiple PLCs

AshleyParr said:

What OPC server are you using? How is it commuinicating?

You will already have a device set up on the OPC server for PLC 1, just add an additional channel or device and point it at your second PLC

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mbartoli said:

Never worked with the Siemens OPC software, but it can't be much different than other OPC server packages. Define what each client PLC is, then define the tags. If you already have that done for PLC-1 use that as a guide for PLC-2. From the PC front end (I am assuming here you have an HMI of some type) it will look no different, just pick the tags to display.

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mk42 said:

Here are some examples showing different ways for the OPC server to get data out of a Siemens PLC (configuration shown is for Portal). Because Siemens, there are 4 different ways to do it. You probably want the "Tag Service" example.

https://support.industry.siemens.com/cs/us/en/view/67295801

Simatic Net is the PC communication suite from Siemens, which includes the OPC server. OPC Scout is the tool you use to test to see if the server is set up correctly (the official lingo is a "test client").

The steps will vary a bit depending on whether you're using Simatic Manager or Portal, but you'll need to create a link in your project between the PLC and the PC Station with the OPC Server. If the two PLCs are in different projects, you may need to either add them to the same "Multiproject" or create a new project with the PC station and two dummy PLCs with the same networking info (IP addresses, etc).

The nice thing about OPC is that there isn't really anything you need to do programming wise in the PLC, the downside is that setting up the SIMATIC Net stuff can be a pain if you've never done it before.

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plutonium said:

Excellent explanation Thanks.

I use TIA portal. PLC's are in different projects.

Can you explain what does it mean to create dummy projects or Multiproject? Any example?

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mk42 said:

Multi-project is a Simatic Manager thing, don't worry about it. It lets you link separate projects together, to make networking stuff easier.

a "Dummy project" is essentially creating a fake PLC in a project that doesn't actually have any logic, just the network information, or maybe also the tag data (tags and DBs). You'll never download the PLC information, but it could be used by an HMI or an OPC server to know what devices they are supposed to communicate to. I know with HMIs you can use a "device proxy" as well; I don't know if that works for Simatic Net or not. Device proxy is essentially a way in Portal to include the info from a PLC in another project, a sort of built in dummy PLC.

Do you have the PLC project from the company that set up PLC1 and the OPC server originally? If so, it might be easiest to just add your PLC to his project, then create the connection to SImatic Net. If not, you'll need to recreate the existing simatic net config in your project, and then add a dummy PLC matching PLC1 in your project.

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JesperMP said:

plutonium.

I am guessing you are pretty young by how you prefer to take a picture with your phone in order to post a screenshot.
Anyway, I could help.
I could give you links to manuals, faqs, sample projects, youtube videos.
But you could help too.
You could post detailed information about the software in use and the PLCs that are connected or needs to be conneced to.
I mean down to the exact type numbers, and version numbers (software and firmware versions).

Always post all the relevant information in the 1st post.

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JesperMP said:

Use your mobile as wifi access point for your laptop.

I dont want to guess by some photos that says nothing.
How hard can it be to just write the exact type no ?

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