You can use Mimic parameters in an expression. They are needed when you are creating embedded Mimics that need to be generic, that is symbol Mimics that are not associated with any particular database item. For more information, see Mimic Parameters in the Geo SCADA Expert Guide to Mimics.
Example:
An embedded Mimic called 'Quality Display' is created. It has a Mimic parameter called CurrentQualityDesc that is associated with the Value property of a text box. The following expression is used to animate the Value property:
"Parameter:CurrentQualityDesc"
The 'Quality Display' Mimic is embedded on another Mimic. The CurrentQualityDesc property of a point named 'AI1' is associated with the Mimic parameter of the embedded 'Quality Display' Mimic. The CurrentQualityDesc value of the 'AI1' point is displayed in the text box.
You can use the browse button in the Expression window to insert a Mimic parameter in your expression (see Selecting a Mimic Parameter). Alternatively, you can enter the Mimic parameter manually (see Syntax of a Mimic Parameter Tag).