Node Red and OPC-UA connection "Client not open on read/write"
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
Comments
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:
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.