DIO__ReadDeviceList (ul_pbar_dio)

 *  Synopsis:
 *    #include <ul_pbar_dio:dio.h>
 *
 *    int DIO__ReadDeviceList( const CDIOLptr listPtr, float *values )
 *
 *  Function intent:
 *    DIO__ReadDeviceList() returns the scaled values for the specified
 *    list of DIO devices with error retry.
 *  Function parameters:
 *    CDIOLptr	listPtr		The unique DIO device list I/O control pointer
 *                              returned by DIO__InitializeDeviceList().
 *    float	*values		pointer to value destination
 *  Function return value:
 *    DIO_OK		success
 *    CBS_INVARG	devicePtr was NULL or invalid
 *    DIO_MEMFAIL	memory allocation failure
 *    DIO_BADARG	invalid number of arguments passed
 *    DIO_SCALEFAIL	no scaling information available
 *    negative value	ACNET format error