UT_DIGITAL_IN — Digital input (debounce, alarm, chatter, simulate)

Conditions a switch, float or contact: debounce, alarm on a
state, detect chatter (a failing switch or a wave-tossed float), and simulate.

Pins

	Pin	Type	Default	What to wire
in	`In`	BOOL	FALSE	The raw input (`%IX…`)
out	`Q`	BOOL		Clean signal (after debounce)
out	`Alarm`	BOOL		Alarm state reached (if configured)
out	`Chatter`	BOOL		Too many changes; `Q` holds its last stable value
out	`Quality`	UT_QUALITY		GOOD, BAD while chattering, SIM when simulated
inout	`Data`	UT_DIGITAL_DATA

Field	Type	Default	Meaning
`onDelay` / `offDelay`	TIME	T#50ms / T#50ms	Debounce: the input must hold its new state this long
`alarmOn`	UT_DI_ALARM	UT_DI_NONE	`UT_DI_NONE`, `UT_DI_WHEN_TRUE`, `UT_DI_WHEN_FALSE` (state of `Q`)
`alarmDelay`	TIME	T#0s	The alarm state must last this long
`alarmReset`	UT_RESET_MODE	UT_RST_AUTO	AUTO clears when `Q` returns; MANUAL holds until reset (refused while still in the alarm state)
`chatterCount`	INT	0	More than this many clean changes within `chatterTime` = chatter (0 = off)
`chatterTime`	TIME	T#10s	Chatter window, and how long the input must be steady to recover
`simulate` / `simValue`	BOOL	FALSE / FALSE	`Q` is `simValue`
`cmdReset`	BOOL		HMI: reset a MANUAL alarm (acts once, cleared by the block)
`cmdDayRollover`	BOOL		Midnight pulse (`UT_SCHEDULE.DayPulse`): `onTime` back to 0 (acts once, cleared)
`q`, `alarm`, `chatter`, `quality`			Status, as the pins
`changes`	UDINT		Changes of the real input after debounce (not simulated ones)
`onTime`	TIME		Time `Q` has been TRUE since the last day rollover
`stateFor`	TIME		Time `Q` has been in its present state, since its last change (or power-up)

Debounce: Q changes once the input has held its new state for onDelay
(turning on) or offDelay (turning off). A pulse or gap shorter than that is
ignored; contact bounce gives one clean change. With a delay of 0, Q follows
the scan the input is seen. A change must last at least one scan to be seen.
Chatter: counts clean changes (after the debounce, so the count is the same
at any scan rate). More than chatterCount within chatterTime sets Chatter,
Quality goes BAD and Q holds its last stable value. It clears once the input
has been steady for chatterTime.
Alarm: a UT_PROTECT warning on the chosen state of Q.
Time in state: stateFor restarts at 0 whenever Q changes (a bounce shorter
than the debounce does not count), e.g. "float high for 12 m".
Simulate: Q = simValue at once, Quality = SIM, the alarm works on the
simulated value (for FAT), chatter is not reported.
Power cut: nothing is kept. changes starts at 0, a MANUAL alarm is forgotten,
and an alarm state that is still there raises the alarm again.

HighFloat(In := NOT %IX0.3, Data := HighFloatCfg);   (* an NC float: inverted at the pin *)