GPIB__Write (ul_pbar_gpib)

 *  Synopsis:
 *    #include <ul_pbar_gpib:gpib.h>
 *
 *    int GPIB__Write( const CGPIBptr modulePtr, const char *command, const int length )
 *
 *  Function intent:
 *    GPIB__Write() selects the specified GPIB module if not currently selected,
 *    and performs the requested GPIB write.
 *  Function parameters:
 *    CGPIBptr	modulePtr	The unique GPIB module I/O control pointer
 *                              returned by GPIB__InitializeModule().
 *    char	*command	The command data to be sent
 *    int	length		The byte count for the data to be sent
 *  Function return value:
 *    CBS_OK		command successfully written
 *    CLIB_NO_SUCH	invalid reference number
 *    CBS_INVARG	invalid GPIB address
 *			no such module type for the given front end
 *			or invalid module pointer
 *    CBS_NODAT		VME interface device could not be retrieved
 *   				for this GPIB address
 *    CBS_NO_SUCH	VME interface device doesn't exist
 *    DIO_xxx		error retrieving VME interface device
 *    otherwise		GAS error