String

A string has to be enclosed within single straight quotation marks, in the format:

<Identifier> = '<string>'

Any string that references an item in the database is case sensitive.

Where a string is to evaluate as an expression:

• Any constant reference to a value in the database has to be enclosed within two sets of single straight quotation marks in that expression. This is in addition to the single straight quotation marks that are required due to the identifier value being a string.

  Example:

  TitleExpr = '''AdHocTrends.Sensor1'''

• Any OPC tag that is used to obtain a value from the database has to be enclosed within two sets of double straight quotation marks in that expression. This is in addition to the single straight quotation marks that are required due to the identifier value being a string.

  Example:

  TitleExpr = '""AdHocTrends.Sensor1.Name""'

Any string used in the expression has to be enclosed in two sets of single straight quotation marks.

Any OPC tag or string that references an item in the database is case sensitive.

For more information on the syntax you can use to reference an item in the database, see Syntax of OPC Property Tags in the ClearSCADA Guide to Expressions.