Siemens S7 PLC connectivity

Hi all,

Based upon a question from a collegue I would like to open up a discussion around connectivity with Siemens S7 PLCs.

I know that Siemens offers multiple series of their S7 PLCs
The 1500 series for instance is able to act as an OPC-UA server, which makes it easy for Cumulocity to communicate with it.
Older series (e.g. 300 series) do not have the ability to communicate using OPC-UA. They only support the OSI-TCP Siemens proprietary protocol.

Cumulocity (currently) doesn’t support this protocol out of the box.

As a proof of concept I am looking at building a microservice based on the Snap7 project.

Do you have any other means to connect the older S7 series PLCs?

By the way, one of my customers has tried using a hardware gateway. The gateway was only capable of connecting a maximum of 3 PLCs due to the fast amount of tags in the PLCs.

1 Like

Hi Misja,
in one of the PoC’s I’ve used SIMATIC IOT2040, which has multiple connection options to the PLC’s, including older ones. Not sure how many PLC’s can be connected at the same time though.

Hi Jose,

if the S7 has an opc-ua server (S7 1500) we can connect native using our ope-ua gateway. If only Profi-Net is supported you might use a protocol gateway like:

Kind Regards,


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