dio_enable(_c)

	status.i4.v = dio_enable(device_index.i4.r, alarm_type.i4.r
				 [,start_block.i4.r] [,num_blocks.i4.r])

	status.i4.v = dio_enable_c(device_index.i4.v, alarm_type.i4.v
				   [,start_block.i4.v] [,num_blocks.i4.v])

	This routine enables an alarm.

	device_index	device index of interest
	alarm_type	type of alarm
			(DIO_ANALOG -> analog alarm,
			 DIO_DIGITAL -> digital alarm)
	[start_block]	starting block to enable (starts at 0)
			(default is 0) (maximum is DIO_MAX_ALARM_BLOCKS - 1)
	[num_blocks]	number of blocks to enable (default is 1)
			(maximum is DIO_MAX_ALARM_BLOCKS)

	This function returns ACNET status values as follows:

	OK			success
	DIO_BADARG		invalid alarm block requested
	otherwise		ACNET format error

	This function requires the following include files:

	diolib_h, acnet_errors_h

	Related functions:

	dio_ena_lst, dio_disable(_c), dio_is_bypas(_c)

	C/C++ usage:

	int	status;
	int	device_index = 14430;
	int	alarm_type = DIO_ANALOG;
	int	start_block = 0;
	int	num_blocks = 1;

	status = dio_enable_c(device_index,alarm_type,start_block,num_blocks);