If I have an OPC tag that returns a string and I would like to convert it to an integer then what is the expression statement to do this? For example, if the strings look like any one of these:
0.0?
125.0?
99.5?
I would like to convert them to the following float values
0.0
125.0
99.5
The ‘?’ is part of what the device returns. I used the replace function to remove the ‘?.’ I used the replace function to remove the ‘.’ and then cast it to integer and float but I get an evaluation error. The evaluation error goes away when I cast to string but all I get are '‘00’, ‘1250’, and ‘995’
Same issue. I even have the tag data type as a Float or an Integer.
Here is the expression
toFloat(replace(replace({[~]Tag},’?’,’’), ‘.’,’’))
Where {[~]Tag} is a string that equals ‘0.0?’
Both of these work for me:
replace({[~]StringTag.value}, '?', '')
toFloat(replace({[~]StringTag.value}, '?', ''))
The first one gets implicitly cast to a float if the expression tag is configured as a Float.
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You should only need one replace operation, if you want to keep the decimal precision in the output:
toFloat(replace({[~]exp/WriteableString1}, "?", ""))
Here is the issue. The string came from an OPC tag and defaulted to 5 characters. In order to convert the value to a float value I needed to trim the excess characters. Here is the final expression:
toFloat(replace(trim({[~]Tag}),"?",""))
Thanks for helping!
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