Function Parameter General Editor

Name

Name of the parameter. Parameter names must start with a capital letter and can contain only alphanumeric characters.

Type

Data type of the parameter.

If an array is desired, append opening and closing square brakets ([]) to the type name. For example, to specify an array of ViReal64, enter ViReal64[].

Tip

The following syntax can be used in the Type text box to create a new enum type and use that enum as the type all in one operation:

new enum TriggerSource; Internal = 2, External = 0x15, Software = 47

See the topic Defining New Data Types Inline for more information on this feature.

Direction

Choose the Input to specify an input parameter.

Choose the Output to specify an output parameter.

Choose the Input/Output to specify an output parameter.

Buffer size

The buffer size combo box will only appear for array parameters and for string output parameters. Use this control to select which parameter indicates the number of array elements (or string characters) allocated by the caller. Only Int32 and Int64 parameters may be used as the buffer size parameter.

Actual size

The actual size combo box will only appear for array output parameters. Use this control to select which parameter indicates the number of array elements returned by the driver to the caller. Only Int32 and Int64 parameters may be used as the actual size parameter.

Tip

For functions with more than one array parameter, each with the same number of elements, it is convenient to have all of the array parameters share a single buffer size parameter and a single actual size parameter. Nimbus initially creates separate buffer size and actual size parameters for each array parameter. Consolidate these by first visiting each array parameter and changing the Buffer size and Actual size combo boxes and then deleting the extra buffer size and actual size parameters. Note that you will not be able to delete a parameter if it is used by an array or string as a buffer size or actual size. Finally, order the parameters such that the shared buffer size parameter appears immediately before the first array parameter, then the array parameters, then the shared actual size parameter.

See also

• Defining New Data Types Inline