Event conditions in groov View -- any way to use a % value?

Is there any way we can use a % value in the limit fields when setting up the event conditions in groov View? I my case, every few hours the tag being monitored (e.g. actual feedrate) changes. We only want to know if the actual feedrate (vs. the setpoint feedrate) differs by more than 20%. I have seen in other posts about people wanting the ability to compare two tag values and then trigger the event, which would solve my problem here.

Just in case it’s not clear…we might be feeding at 100 lbs/hr (meaning ±20 lbs is acceptable), but then an hour later, feed at 900 lbs/hr (meaning ±180 lbs is acceptable). This is why entering a % value (e.g. 20) would address all possible situations.

Can you run the condition in your strategy and set a flag when it is in alarm? Groov can then monitor the flag variable.

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I second @philip. That would be the way I would go about it.
Do the calculation in the strategy to percent and just have an alarm flag that you attach to the groov Event.

You could also add a variable in your strategy for the feed error, that would be the setpoint/actual. Then in your groov event you can use > 1.2 or <0.8 on the feed error variable. This may even be useful for trending. Watch for divide by zero though.