Applies To:
  • CitectSCADA 3.xx, 4.xx, 5.xx
Summary:
Knowledge Base article Q1244 describes the behaviour of [CTEDIT]MaxHelpRec under Windows 16 versions of Citect.

Sometimes when you click on a drop down combobox or listbox to get a list of options, a "list too big" message is displayed. This warning will display if the number of records exceeds a predefined value (2000 by default). The reason for this limitation is that Windows 9x places limitations on the number of entries in comboboxes and listboxes, and the time to load the information from the database can also be excessive. On Windows 9x and Windows NT based platforms there is no longer a limit to the total amount of data that may be placed in these controls. There is also no limit to the number of items that may be placed in these controls on Windows NT based platforms (NT, 2000, XP).

 

Solution:
You can increase the default value (2000) of maximum items that will be displayed in combobox or listbox's with the variable [CTEDIT]MaxHelpRec. You can also modify the variable while CTEdit (the Database Editor) is running by changing "Maximum list box items" in the Tools/Options dialog box. If you use the Tools/Options method, you may still get the "list too big" warning because the data in the combobox or listbox is cached. To clear the cache, shutdown and restart CtEdit. Also note that setting the value very high may also affect the performance of the affected controls.

Prior to Citect version 5.41 the maximum value you could set MaxHelpRec to was 32,767. If you exceeded that value, you would overflow the setting causing unpredictable values.

In Citect version 5.41 the maximum you can set this value too is operating system specific. If running on a Windows NT based platform, you may set this value as high as 2,147,483,647. On Windows 9x platforms, you may set this value to a maximum of 32,767. If you exceed these values, MaxHelpRec will be set to the default, 2000.

 
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