wg_get_root_device_c

	status.i4.v = wg_get_root_device_c(device_names.i1a.r,
					   root_devices.i1a.r,
					   errors.i2a.r [,num_devices.i4.v])

	This routine returns the root device for requested waveform generator
	devices.

	device_names	device names
			(dio_get_terse_name_length characters per device)
	root_devices	returned root device names
			(dio_get_terse_name_length characters per device)
	errors		returned device error or array of errors
			(OK -> success,
			 DIO_INVDEV -> not a supported waveform generator
				       device) 
	[num_devices]	number of devices (default is 1)

	This function returns ACNET status values as follows:

	OK			success
	DIO_xxx			error retrieving database info
	positive value		number of devices in error

	This function requires the following include files:

	ul_cbsaux_h:auxlib_device_h, acnet_errors_h

	Related functions:

	wg_get_root_device_by_di_c, wg_device_type_c, wg_get_device_c,
	dio_get_terse_name_length, dio_set_terse_name_length_c

	C/C++ usage:

	static const char	device_names[NUM_DEVICES*DEVICE_TERSE_NAME_LEN+1] =
	"B:XQ1   B:XQ2   ";
	char	root_devices[NUM_DEVICES*DEVICE_TERSE_NAME_LEN];
	short	errors[NUM_DEVICES];
	int	status;
	int	num_devices = NUM_DEVICES;

	status = wg_get_root_device_c(device_names,root_devices,errors,
				      num_devices);