Is there a limit on how many nodes can be subscribed to?

[ctsaitsao]

Hi, I am encountering issues receiving data from a few PLC nodes that are added later on during my program and would like to know if there's a limit to how many nodes can be fed to the subscribe_data_change() method or if there are ways to avoid possible race conditions. I am not sure how datachange_notification() works under the hood so an explanation of that would help as well.

[AndreasHeine]

yes a serverside limit! s7 for example have 10k to 20k max monitored items per subscription depending on the model could also be lower.

[ctsaitsao]

Hm, I definitely wouldn't be exceeding such a limit.

However, I am calling subscribe_data_change() multiple times and was wondering if this can lead to duplicate subscriptions being created (basically, I call it every time I want to get data from a new node).

Thanks for answering!

[AndreasHeine]

no it will just add a monitoreditem to the subscription!