Tag Error in ST Program when Saving or Executed

[sbeadle1]

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In some cases a structured text program may reports a tag error whilst the object is there and appears valid. The error may appears while saving saying:

Compile...Tag error: Test.CurrentValue not found

Or when using direct variables, a message box appears saying:

Program contains errors

To resolve this, check using the schema and data source bar that the object name and property are spelt correctly. A database object name is case-sensitive, whilst the property names are case-insensitive.

Another reason could be the fact that you have put spaces in the variable declaration, however the spaces are used in the database location, for example:

VarName AT %M(.Analogue.CurrentValue) : LREAL;

and

VarName AT %M( .Analogue.CurrentValue) : LREAL;

are referring to two different database locations.

Putting an extra space in is easily done, especially when using indirect variables, so some care should be taken when declaring variables.

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