mio_cancel

	status.i4.v = mio_cancel(num_devices.i4.v, device_indices.i4a.r,
				 properties.i2a.r, errors.i2a.r)

	This routine removes devices from the MIO pool.  This allows one to
	reinitialize or freshly repopulate device/property memory.

	num_devices	number of devices or special argument as follows:
			(0 -> remove all devices from the mio pool,
			 -1 -> remove all devices and release mio memory)
	device_indices	device indexes
	properties	property indexes
	errors		returned device errors

	This function returns ACNET status values as follows:

	OK			success
	negative value		overall ACNET error
	positive value		number of devices in error

	This function requires the following include files:

	dbprops_h, diolib_h, acnet_errors_h, tclk_events_h

	Related functions:

	dio_simulate, mio_read, mio_set, mio_fill_status

	C/C++ usage:

	static const short	properties[NUM_DEVICES] = {PRSET, PRSET};
	short	errors[NUM_DEVICES];
	int	status;
	int	num_devices = NUM_DEVICES;
	static const int	device_indices[NUM_DEVICES] = {14430, 14431};

	status = mio_cancel(num_devices,device_indices,properties,errors);