OPCUA communication slow

Hi everyone!

I want to make a communication between my Node-RED server, which runs on my PC and a PFC100 WAGO PLC . After deploying and rebooting both systems, the communication works well but after a few minutes it's continuously getting slower and some of the active connections go inactive. I tried to delay the messages, but the way it worked its look terrible. Does anyone know the solution to this problem? Could someone help me solve this? Thank you!!

If you could watch the code , it would be clear , why i thinks its terrible.
opcua com flow.json (55.5 KB)

How are the delay nodes configured ? As delays or as rate limiters ?
Try rate limit with 'drop immediate msgs'

Why not use a listener and just let the data come through as it comes.

I don't know the internals of the nodes you're using but perhaps it's creating objects every 1s. Might be a memory leak?

Anyhow, check out the built in examples. Node-red menu button (top right) --> import --> examples --> iiot

Thanks for your help , They are configured as delays. i understand , what rate limiters are , but i am not know, how should they solve my problem.

I am not using the iiot opc ua library . I tried to use "subsribe" type nodes , but it is not working well. The reason why i need them , is that the plc writes the variables. So if i switch on the 50% and 100% motor parallel, the plc switch them off , so this is why i want to read they state. With subsribe it works sometimes , but sometimes not.

I have the same problem,when i use subscribe, sometimes work but sometimes not

Try using the IIOT nodes instead.


Yes,i use iiot instead. the problem is iiot. others,i can't find the method to pub in iiot,i only find the method node to sub

not sure what you mean?

At first you say "when i use subscribe, sometimes work but sometimes not"

  • So are you using Listener and Response nodes for reading?

Now you say "i can't find the method to pub in iiot,i only find the method node to sub"

  • Are you saying you cant find a way to write?

i use the cs(client,server) mode to read and write before,but, When I try to use pub,sub mode,i only finded sub node(listener),and the sub response has no data sometimes,only response when the data change?

I believe thats how its supposed to work. Only get data upon change It minimises traffic.

If you need data adhoc, you can use a read node.

thank you very much, and ,iiot don't have pub node?only have write node?

Look in tool bar. No pub, no sub - but many others.

There are even a shed load of built in samples/demos...

thank you