I am trying to understand how to set up subscription settings for my OPC UA tags in Ignition V8.0.9 and I faced some issues that I need an assistance with:
what is the relation on publishing interval and rate (when direct mode is selected). I ve read other forum topic where it was explained that rate is sample time and Publishing interval behind OPC UA tab is publish time. What happens if rate is bigger than Publishing interval? Is it so that if rate is set bigger, then it is set to publishing interval (somewhere behind the scenes). I tried to set 10 seconds rate (Driven) and 1 second Publishing interval just for testing, and it results in 5 seconds publishing interval. It is really confusing.
When driven mode is selected for OPC UA tag does it only change sampling time when condition is met? If it is like that, then it does not give much benefit, I need to make faster publishing from server to Ignition once the condition is met. Is it somehow possible? Does driven and leased modes at all make sense when using OPC UA, because they do not modify publishing time at all, only rate?
Is it somehow possible to trigger data read on demand? For example I have OPC UA tag group with publishing interval 30 seconds and I want Ignition to update all tags when for example I press some button. Is it possible to accomplish? Like in between 2 publish requests?
Last issue…sorry I just havent faced much with queue size before, so I am not sure how it works. So if I have OPC tag defined and I assign it to tag group where rate is 1 second, publishing interval is 10 seconds and queue size is 10, does it mean that every 10 seconds server will send 10 values? But then in tag value I only see one value (which I assume is the last one), not 10. Where are those other 10 values? Are they used for some historian or trend applications inside Ignition or they could be saved to SQL server?
Thanks in advance!