# Create a parameter file

If a graphic display contains tag placeholders, you can specify a parameter file to supply tag or folder names, or parts of tag names, for the placeholders at run time or in test display mode. This allows you to use different sets of tags with a single graphic display.

Tip: | The recommended maximum number of tag placeholders to be used for a single graphic display is 500. If the display contains a display list selector object, you can also provide parameters for tag placeholders, using a parameter list.

## To create a parameter file:

1. Open the Parameters editor using one of these methods:
   - From the File menu, select New > Parameter.
   - In the Explorer window, double-click the Graphics folder to expand it, right-click Parameters and select New.
2. In the Parameters editor, for each tag placeholder in the graphic display, type a definition using the format:

   `<#number>=<string>` where string can be a tag or folder name, or any part of a tag name, for any kind of tag.

   For example, to use a tag called Pea_Weight in a folder called Canning, the definition in the parameter file could be one of these:

   `#1=Pea_Weight`

   `#1=Canning\Pea_Weight`

   `#1=Canning`

   Using only the folder name Canning, the graphic display could contain the placeholders, `#1\Weight`, `#1\Level`, and `#1\Temp`.

   Tip: | Instead of typing the tag name, you can use the Tag Browser. Double-click in the editor and select a tag. The selected tag name is inserted in front of the cursor.

3. Save the file using a name that will identify the set of tags defined in the file, for example, Canning display tags.

   Tip: | The parameter file editor automatically inserts these characters at the top of the file: @!=1 This means that only if the exclamation mark is at the beginning of a line, will the text that follows the exclamation mark be treated as a comment. If an exclamation mark occurs anywhere else on the line, whatever follows it is not treated as a comment. To be able to start a comment elsewhere in a line, delete @!=1 from the beginning of the parameter file. When you do this, an exclamation mark can be placed anywhere in a line, and whatever follows it is treated as a comment. The parameter can be any portion of a tag name. When a parameter file is called, the placeholder is replaced with whatever portion of the tag name is specified by its corresponding parameter.

## See also

Parameter file and parameter list

Create parameter lists

Causes of run-time errors for parameter files

Tag placeholders

Parameter passing