status.i4.v = dio_is_on(device_index.i4.r, on_status.i4.r
				[,on_text.i1a.r] [,ftd.i2.r])

	status.i4.v = dio_is_on_c(device_index.i4.v, on_status.i4.r
				  [,on_text.i1a.r] [,ftd.i2.v])

	This routine retrieves device on/off status.

	device_index	device index
	on_status	returned on/off status
			(TRUE -> device is on,
			 FALSE -> device is off,
			 DIO_NOATT -> on/off attribute is not defined)
	[on_text]	returned 4 characters of status text ("ON  " or "OFF ")
			(default is NULL)
	[ftd]		frequency/time that data is collected
			(FTD_ONESHOT -> one shot (default),
			 FTD_DEFAULT -> use database default FTD,
			 FTD_1HZ -> 1 Hz request,
			 FTD_EVENT_MASK OR'ed with TCLK event value -> read
			 on TCLK event (event constants are in 'tclk_events')
			 (can use the macro BUILD_EVENT_FTD(event) or
			  BUILD_EVENT_PLUS_DELAY_FTD(event,delay) in 'macro'))

	This function returns ACNET status values as follows:

	OK			success
	DIO_BADARG		invalid number of arguments passed
	negative value		ACNET format error

	This function requires the following include files:

	cnsparam_h, diolib_h, acnet_errors_h, tclk_events_h, macro_h

	Related functions:

	dio_is_on_lst, dio_status(_c), dio_is_ready(_c), dio_is_remote(_c),
	dio_is_positive(_c), dio_raw_to_status_c, dio_raw_to_status_extended_c

	C/C++ usage:

	char	on_text[4];
	short	ftd = FTD_ONESHOT;
	int	status;
	int	device_index = 14430;
	int	on_status;

	status = dio_is_on_c(device_index,&on_status,on_text,ftd);