I am considering using Ignition for applications where we have traditionally used a PanelView or other stand-alone HMI. One question I have is in regard to alerts. From what I understand, alerts are configured individually for each SQLTag. I have used HMIs like this before and it is always cumbersome creating / defining alerts. Typically I have an array or table of INTs or DINTs in my PLC. On a PanelView I can quickly create a chart of alarms where each alarm is activated by a particular bit in the array or table. Is there any way to do this with Ignition?
Unfortunately, the answer is no. Alerts are configured per tag as either a digital alert or analog alert. In order to alert of a bit in an array you have to separate the bit out.
If I am not using a tag, and there is not an alert defined for that tag, will Ignition still actively update that tag? Since I typically keep all my faults in an array, I could use Excel to quickly edit and create all possible alarm tags and them import back to Ignition. I would then enable the alert and enter the proper alarm text for each fault. A lot of them may not be used however so I don’t want Ignition reading all the fault tags unnecessarily.
If you have a tag defined in SQLTags it does get scanned even though you may or may not be using it.
All SQLTags (tags) have a scan class. The scan class dictates when the values are updated. The default is direct which means it always scans the tag at a certain rate. We do have two other modes leased and driven but they have to do with scanning them on certain conditions, not when you are not using a tag.
The nice thing is you can break up the array into multiple tags and delete the ones you are not using.
All tags also have an “enabled” flag that you could toggle to make sure they didn’t get updated if they weren’t being used.