Expression not returning expected valuebut only for ON and OFF keyword

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1

I have an expression if({PLCTAG/M24_MF}, "ON", "OFF") and instead of ON and OFF it returns me 1 and 0 respectively. I tried ONN and OFFF in expression
if({PLCTAG/M24_MF}, "ONN", "OFFF") and it works as intended returning me ONN or OFFF. Only ON and OFF does not work other all string works.

2

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3

I am unable to reproduce the problem on 8.1.41.

I have an expression tag bound to myBool (a boolean tag).
if({[default]myBool}, "ON", "OFF")

It works as expected.

What is the data type of M24_MF?

4

It's a boolean.

5

Where's the expression/what's the output data type?
I think there's some (misguided, legacy, has to be kept for backwards compatibility) coercion code for certain strings like on/off, yes/no to boolean values in the expression language. You need to share more about where you're authoring this expression to know where the problem lies.

6

Would it fix it to specify Unicode to force string type?
if({[default]myBool}, u'ON', u'OFF')

[Edit: The answer is no. You'll get Error_Configuration("RuntimeException: Syntax Error on Token: 'String CONST' (Line ..., Char ...))
]

7

Can you do that in expressions ?

8

Apparently not - now that I've tried it.