msvargas / node-logix Goto Github PK

Not an issue per say, more a usage question.

Is it feasible/possible to code an event to trap when a PLC tag value changes? Some kind of a subscription system.
I would like to publish to a MQTT topic, but only if the tag value has changed.

If no built-in feature allows for this, I was planning to implement an array of "tag objects" that would hold something like
( tagName, lastValue, currentValue ) and then regularly poll & compare the currentValue with the lastValue for each tags to be monitored.

Not the most elegant. Do you have a better solution?

Hi,
Is there a way to get this as a node in Node-RED running on Hassio?
I cannot find it in the pallette.

Looks like node10 throws an error when trying to catch SIGKILL/SIGSTOP. Earlier versions (<8) did not do this.

Error: uv_signal_start EINVAL
at process. (internal/process/main_thread_only.js:92:15)
at process.emit (events.js:198:13)
at _addListener (events.js:224:14)
at process.addListener (events.js:272:10)
at process.once (events.js:301:8)
at new PLC (/usr/local/lib/node_modules/node-logix/build/commonjs/src/PLC.js:169:21)

I tried simple Connections and simple tag reads.
My promises are getting fulfilled and i'm getting the data i need.
but for some reasons, the program continues to run with an empty Callstack. (a certain timeout event is hanging somewhere in the library). Please Advise.

When I try to run the Example with events, read and write tags the console prints TypeError: PLC is not a constructor

I am using node red and a micro850 within my house. i think you could help me creating your code into a node red compliant setup as i am not a programmer (rather an old plc programmer:-S).
Is their any possibility to help me with this as the node-red-contrib-cip-ethernet-ip gives me the connection error you are taking about...

would be great helpt to automatically read/write directly to tags from node red.

Thx

I don't see a slot property for PLC class, or how to give different slot in the examples.
Could you please provide an example for a diff slot?