You can configure an Express VI such that a help file launches when you click the Help button in the configuration dialog box. You also can configure an Express VI to display the current configuration in the Context Help window.
Use the Control Online Help function to associate help files with Express VIs so that a help file launches when you click the Help button in the configuration dialog box. This function appears on the block diagram of each configuration dialog box VI you build.
The Control Online Help function opens a .chm or .html file located in a directory that you specify in the Path to the help file input. The function searches the file for text that you specify in the String to search for input and opens the file at that point in the text.
Use the genHelp VI to display the current configuration of an Express VI in the Context Help window. The genHelp VI specifies the controls whose values you want to display in the Context Help window when you hover over the Express VI on the block diagram. You also can specify text, such as the control names, to precede the control values in the Context Help window. The genHelp VI appears as a subVI in the configuration dialog box VI for all Express VIs you create using the Express VI Creator wizard. The name of this subVI is genHelpExpressVIName.
The ex_PPGetProp subVI of the genHelp VI appends control values to help strings. Use a separate copy of the ex_PPGetProp VI for each control that contains a value you want to display in the Context Help window. The ex_PPGetProp VI concatenates the help for each control, so you must wire the output from one copy of the VI to the input of the subsequent VI.
After you configure the genHelp VI for the Express VI, the Context Help window updates each time you close the configuration dialog box of the Express VI. If you do not modify the genHelp VI appropriately, an error message related to context help appears when you close the configuration dialog box. Additionally, the corresponding validation test for the Express VI fails.