GPIB__SerialPoll (ul_pbar_gpib)

 *  Synopsis:
 *    #include <ul_pbar_gpib:gpib.h>
 *
 *    int GPIB__SerialPoll( const CGPIBptr modulePtr, const char *pollData )
 *
 *  Function intent:
 *    GPIB__SerialPoll() selects the specified GPIB module if not currently
 *    selected, and performs a serial poll from the module.
 *  Function parameters:
 *    CGPIBptr	modulePtr	The unique GPIB module I/O control pointer
 *                              returned by GPIB__InitializeModule().
 *    char	*pollData	The serial poll response byte
 *  Function return value:
 *    CBS_OK		command successfully completed
 *    CLIB_NO_SUCH	invalid reference number
 *    CBS_INVARG	invalid device address or
 *  			VME interfaced device selected
 *			or invalid module pointer
 *    otherwise		GAS error