We are new to Ignition and are wanting to use it as a backup system for our Rockwell Transaction manager. We have pipe get weighed on a scale and when it is placed on the scale, the PLC will not weigh it till it settles and a tag is set back to 0. Also there needs to be at least 200 pounds of weight so it doesn't write back to the SQL DB an empty weight when not in use. How can we reproduce this in Ignition? See below for the trigger in Transaction manager
If we're talking about using a transaction group, then you will need to add an expression item to act as the trigger.
- Be sure to select 'Run Always', and set the target at the bottom to 'Read Only'. Otherwise it will log the trigger value, as well.
Set up the table in the Action tab:
This part gets a bit more involved. In the Trigger tab,
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check 'Only evaluate when values have changed'
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set the dropdown beneath it to custom,
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select the settling boolean
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Check Execute this group on a trigger
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On the trigger item dropdown, pick the expression item.
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For the trigger conditions, select 'is !=0 (or true)
This works because the group will evaluate only when there is a change on the settling bit, but it will only log the weight if the trigger conditions are true.
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Thanks for your reply. I did figure it out doing something similar. One thing I was not sure about, but the execution scheduling is that just how often it goes to the database or what exactly does that do? One of the problems I had was thinking it was looking at the tags and I had it set for 1 minute
Also, is it better to have multiple transaction groups and one project or multiple projects looking at different groups of PLC tags?