states_callback_init

	status.i4.v = states_callback_init(num_devices.i4.v,
					   device_indices.i4a.r,
					   states_handler.f.v
					   [,handler_data.g.v])

	This routine links finite state machine device changes to a
	user specified function.  The States Callback Facility will call the
	"states_handler" function whenever a multicast message from the
	States front end contains a state change for one of the specified
	devices.  The "states_handler" function is passed the States
	device index, the current state value, and a typecode specifying
	the type of update.  Please, note that it is important that the
	calling program calls acnet_callback_flush to service the
	incoming state events.

	To remove a callback previously established with this function, pass
	the orginal "states_handler" address and the negative value of the
	original "device_indices".

	num_devices	number of devices in list
	device_indices	list of device indices  (To receive reports for
			all devices, use the constant STATES_ALL_DEVICES.)
	callback_func	handler function which is called when one or
			more of the devices undergoes a state change.
			It has the following prototype:
			void states_handler(int vmdi, unsigned short vmstate, 
					    short vmtc, unsigned int secs,
					    unsigned int nanos,
					    void *handler_data)
			where:
				"vmdi" is the device index
				"vmstate" is the current setting
				"vmtc" is the typecode designating the type
				       of update  (Reports emanating from
				       States device settings have a typecode
				       of STATES_TC_STATE_SET.)
                               "secs" the time_t of notification
                               "nanos" is the nanosecs into secs of notification
				"handler_data" is the pointer to user
					       supplied data
			(function of type states_handler)
	[handler_data]	pointer to user-supplied data to be passed to
			states handler function (default is NULL)

	This function returns ACNET status values as follows:

	OK			success
	CBS_INVARG		invalid number of devices requested
	CLIB_NOINIT		ACNET callbacks have not been set up by a
				call to acnet_callback_handle
	ACNET_UTIME		request timed out

	This function requires the following include files:

	clib_h, cnsparam_h, cns_data_structs_h, acnet_h, acnet_errors_h

	Related functions:

	state_condition_met_c, states_telldi, acnet_callback_flush,
	acnet_callback_handle

	C/C++ usage:

	int	status;
	int	num_devices = 1;
	int	states_device_index = 93690;
	void	callback_func(int vmdi, unsigned short vmstate, short vmtc,
			      unsigned int secs, unsigned int nanos,
			      void *handler_data);
	void	*handler_data = (void *) NULL;

	status = states_callback_init(num_devices,&states_device_index,
				      states_handler,handler_data);