Trigger – Rising Edge (Once) Video at Inductive University

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[00:00] One common triggering situation is to trigger a group on the rising edge event of a Tag change. So, for example, let's say we have a Boolean tag that we want to use as our trigger. We could bring it into the Group, and, because in this case we only want to use it as a trigger, we can make the item Read Only. On the Trigger tab, I can select that item, choose the Above Zero condition, and then, most importantly, select "Only execute once while the trigger is active". This means that the first time that the group evaluates the item and sees it as a High condition, it will lock that value in and will not let it trigger again until it sees it go back to False. And I save the Group. We can now see that rows are only inserted each time the tag transitions to True. Nothing else occurs until we take it back to False, and then back to True again. This is what is considered a rising edge trigger. Of course, we could also use On Zero, or one of the range conditions. Any of these modes are compatible with the "Only execute once" condition.

One common triggering situation is to trigger a group on the rising edge event of a Tag change. So, for example, let's say we have a Boolean tag that we want to use as our trigger. We could bring it into the Group, and, because in this case we only want to use it as a trigger, we can make the item Read Only. On the Trigger tab, I can select that item, choose the Above Zero condition, and then, most importantly, select "Only execute once while the trigger is active". This means that the first time that the group evaluates the item and sees it as a High condition, it will lock that value in and will not let it trigger again until it sees it go back to False. And I save the Group. We can now see that rows are only inserted each time the tag transitions to True. Nothing else occurs until we take it back to False, and then back to True again. This is what is considered a rising edge trigger. Of course, we could also use On Zero, or one of the range conditions. Any of these modes are compatible with the "Only execute once" condition.

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