Dear all,

even if the topic is old I'd like to use it in order to understand an error message when I try to connect with UA server. I'm receiving the error "An error occurred while searching for endpoints. Object reference not set to an instance of an object". Has somebody any idea, please? I care to underline that I could connect and communicate with the PLC (PLC sim 1500) in other VM by other OPC client, but I couldn't do it with OPC Scout 10.

Thanks in advance.

Max

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Split from Unable to access data on OPC Scout V10.

Hello

you have to guve us more information:

- Which OPC UA Server do you use?

- Do you use the OPC UA Server in the S71500 PLC itself?

- Which TIA Portal Version do you use?

- Which Security and connection settings do you use?

Bye Murof

Hello,

We are facing exactly same problem what mention in initial question.

Can you please give us the solution for this, how we rectify the problem

We are using 427C IPC with RTX as client

SimaticNET use Version-7.1.2.0

Enable OPC UA check for S7 Protocol

Restart the OPC server.

After that I am able to see the variable in OPC Scout in Local COM Server\OPC.SimaticNET\SYM

But when I try to connect with UA Server and check for opc.tcp:// host name:4845 and press discover

then No endpoint found with below error-

An error occurred while searching for endpoints.

Object reference not set to an instance of an object.

Kindly suggest for this issue.

Hello sagark12

Can you please explain a little bit more detailed, Which one is OPC UA Server and which Device or Software is OPC UA Client?

I always thought that OPC UA funcitonality comes with a newer Version than Simatic NEt V7.X (V12 or something....)

Bye Murof

Hello,

This problem is resolved by enable/tick mark the option  "use as target for symbol download".

Hello,

Can you explain more about (mark the option"use as target for symbol download"). Where can I find this.

I'm trying to connect Xamarin Form (OPC UA Client) to PLC S71500 (server) and I face this error: "object reference not set to an instance of an object". 

I'm looking forward to hearing from you,

Thank you so much!!

Hello leafgreen1

Please give us some more Information:

- Which TIA Portal Version do you use?

- Which S1500 and FW Version do you use?

- Check the FAQs if you have done all nessesary steps:

https://support.industry.siemens.com/cs/de/en/view/109737901

Bye Murof