Connecting to integrated S7 1500 OPC server

I’ve been having a lot of issues getting a connection to a Siemens s7 1500 PLC. I’m now attempting to use Siemens inbuilt OPC UA but getting connection errors. I’m wondering if anyone has any experience with the integrated OPC servers of the newer siemens PLCs, and how to get them to function with ignition.

What version of Ignition are you using? What issues are you having?

Connecting without security to the OPC UA server on the S7-1500 should be no problem. With security, the only hassle is dealing with certificate approval on either side.


I’m a bit confused as to how to do it. Is it considered a third party OPC server? When I put in the IP address given by TIA portal as an endpoint URL, I get the following error:

UaException: status=Bad_ConnectionRejected,$AnnotatedConnectException: Connection refused: no 
further information: /

Yes, it’s just a 3rd party OPC UA server.

This is just a straightforward networking error.

If you can ping this IP from the Ignition gateway, then maybe the server isn’t enabled or maybe you need to recompile and download the program or restart the PLC. Or see if a firewall is preventing outbound TCP connections on port 4840.


We use the S7-1500 OPC UA Server extensively and are still in communication with Siemens to sort some issues out.

The server reboots on ANY download to the PLC, even changing a rung of code will make the server reboot. Upon first load, the server is overwhelmed by the number of initial reads. You can overcome this by setting the Max per Operation property in Advanced to 64 (you can experiment with slightly higher). This way the server can at least reestablish the connection.

Siemens has promised me that it will be fixed properly in TIA v16, releasing in November. We’ll see.

Once the server is connected and recovered after a download, it works beautifully. Just beware the restart issue.


6 months ago I’ve been testing Siemens OPC UA server in the new CPU1515-2PN and TIA v15.1.
If I used the Ignition driver for Siemens CPU1500, I had no problem with more than 17000 tags used in our project.
But when I switched to Siemens OPC UA from the CPU, then I couldn’t use more than about 2000 tags.
When I had all 17000 tags active, then all tags have communication errors every few seconds…
And even with the 2000 tags, the response time was terrible: when I pressed the button in the Ignition to set a bit tag in the PLC, it would be set in the PLC after a few seconds… And that was with no program actively running in the PLC. Only around 20 DB. When we try to run the real program, the cycle time was way too big to be useful. And in the status page on the Ignition gateway for the device, you could see the load factor over 100% for tags with scan class 1s, while with Ignition S7-1500 driver (with 17000 tags) we had load factor around 30%.

As far as I can remember, I think I read somewhere in the Siemens documentation, that recommended number of tags is 2000… that is useless…

But… maybe I was doing something wrong…:neutral_face:


We run 1513 CPUs with about 5000 tags each. 1s update rate is no problem at all.

There is an option in the UA server to limit the number of nodes. Max in a 1513 is 10000, don’t know about 1515.

Make sure you are running the latest firmware. They have been improving it every release, promising me that in November it will be stable on download.


You have to access structures as a whole rather than subscribing to individual components or you will suffer a huge performance hit.

This requires some of extra work on the Ignition side, though. I outlined the general strategy in this post.

1 Like


is there any performance test report for OPCUA client reading ability of Igntion such as reading tags with each tag has 1000 byte?

I use PLC OPCUA server and Ignition will read about 50 UDT tags every second instead of invidual tags, the UDT data length(documention data type) is about 1000 bytes

There’s no reports like that.

You will max out the comms capabilities of the PLC long before you have a problem in ignition.

Are you reading explicitly with a scripting call or using tags and subscriptions?

@Kevin, thanks for your info.

I just drags the OPC UDT tag from OPCUA server to the Tag diretory of Ignition. Then bind the tags to a user defined function tempalte for usage.

Ok just confirming. That’s best case for Ignition because it’s a subscription, the PLC only sends new values when they change.

I am also having problems with certificate exchange. I was not able to install Ignition OPC UA Client on Tia Portal v15.1 because of “invalid certificate” response. Is there a known trick to solve this problem?