Parameter access functions are datatype specific. Use the parameter access function GetDataType to return the datatype of a parameter. Then use a parameter access function corresponding to this datatype to return information about the parameter.
A parameter passed to an external procedure belongs to the datatype TINFParam*. The header file infparam.h defines the related access functions. The Designer generates stub code that includes comments indicating the parameter datatype. You can also determine the datatype of a parameter in the corresponding External Procedure transformation in the Designer.