Dear community, at the moment I am trying to connect the PLCnext with Node Red over UPC-UA. The goal is to read data form the PLCnext and display it on Node Red. After installing node-red-contrib-iiot-opcua with version 2.7.1 an exception raised - openssl could not create certificate files. I noticed that there is a solution for this problem in the community (https://www.plcnext-community.net/en/hn-makers-blog/419-problems-with-node-red-opc-ua.html) and I followed the instructions to solve it. The node red server runs and the nodes for OPCUA connection are available. As the certificate was added manual I configured a flow the same way as in the tutorial (https://www.plcnext-community.net/en/hn-makers-blog/301-automation-maker-003-node-red-as-opc-ua-client.html). There was a strange behaviour. If I set the security mode to “sign&encrypt;” the node tries to connect but it is never successfull. If I change it to “none” security mode the connection is “active”. But if the flow gets injected then an error arises: “Error: Client not open on read”. I tried different versions and configurations but never was able to read the opc values over Node Red. With the UA-Expert client it is possible to read and write the OPC-UA values. My actual environment: PLCnext Firmware : 2020.0 Node.js : 10.15.3 - installed from PLCnext Store npm version : 6.4.1 Node-red : 0.20.5 node-red-contrib-iiot-opcua : 2.7.1 Anyone of you had the same problem? Maybe someone could write his configuration with node red and OPC-UA running. Best regards Steffen Krätzig
I tried the same with node-red-contrib-iiot-opcua Version 2.7.1. The read node shows “connecting…” and after a few seconds, the connection to node-red is lost and I have to restart my PLC. The PLC itself is still running. So at the moment I do not know how to solve this issue. If someone has successfully used the OPC UA nodes with the AXC please share your experience. Just for testing I have installed the latest version on my raspberry pi. The installation works without any problems but when I deploy my flow, the read node stays on connecting forever. So at the moment I have no idea where to look for the problems.
I finally managed to install the latest version of the node-red-contrib-iiot-opcua. Here are my steps: 1. Update node-gyp:
npm install -g [node-gyp@latest > > 2](mailto:node-gyp@latest</pre). install ipkg (see makers blog) > > 3. install gcc > > 4. install make > > 5. install opcua : npm install -g node-red-contrib-iiot-opcua --unsafe-perm --build-from-source > > >
When I try to connect to the OPC UA server with the latest version of the opcua nodes, I get the following message in node-red: Error: End point must exist opc.tcp://192.168.178.10:4840/ Using UAExpert to connect with the above URL it works. When I use the node-red-contrib-opcua nodes everything works like expected.