Start and Stop Transaction Group Trigger with Different Tags

Ignition
1

I’m looking to start a transaction group with 1 tag and stop it with another. Essentially there is a cycle start and cycle complete. I’m looking to log data when the start cycle bit comes on and stop logging when the cycle complete bit comes on.

The only way I can think of would be to create a “InCycle” memory bit that is driven by the tag event scripts to set it and clear it. There must be a better way.

2

Use an expression tag:

{path/to/CycleStart} && !{path/to/CycleStop}

3

I realized I made a mistake in stating the question. The CycleStart and CycleStop is essentially a one shot. They are pulsed only.

4

Yeah, then you’re looking at scripting.

In that case, it would be much more reliable if you can toggle the InCycle bit in the PLC.

5

You can’t trust Ignition to catch that sort of this, unless they are held at least as long as any possible java GC event (multiple seconds) plus your OPC poll rate. You will suffer until you do this in the PLC.