Limiting set point inputs

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1

I have an operator set point tag that I want to limit the amount of change to some value like -/+ 10%. For example if the set point tag is 0.5, I want to limit the range of input between 0.45 to 0.55. Any value entered outside my range gets rejected and pops up an message.

How do I do something like this?

2

Use a Numeric Text Field, bind your tag to the property Value(Double) and set it to Bidirectional, enable the Use Bounds and Error on Out-of-Bounds properties, and then bind the Maximum and Minimum properties to expressions like -

if({myTag}!=0.0, {myTag}*1.1, 0.5)and

if({myTag}!=0.0, {myTag}*0.9, -0.5)

The 0.5 and -0.5 would be the default values in case the myTag value was 0, make those values whatever ya want.

3

That works great for a numeric text field but I can’t seem to make it work with a numeric key pad.

4

The numeric keypad will never have a limit on it, but it you turn on the Use Bounds property on the numeric input, then any input out of your min/max range will be set to the min or max value.