UT_SCHEDULE — Weekly time-of-day schedule

Switches an output on during time windows on chosen days (irrigation, lighting,
HVAC occupancy, off-peak pumping). It gives hour/day pulses for totals and reports,
and an operator override.

Pins

Window slot UT_SCHED_WINDOW

Record UT_SCHED_DATA

How it works

• Windows. A window is on from start up to (not including) stop, on each day set
  in days. A window that crosses midnight belongs to the day it starts: Sunday
  22:00–02:00 runs Sunday night into Monday morning. start = stop is an empty
  window. Overlapping windows simply combine; Window shows the first active one.
  Times are handled to the second.
• Every N days. everyDays 2 runs a window every second day from startDate
  (irrigation on alternate days), 3 every third day, and so on, and only on days
  days also allows. startDate is day 1; before it the window is off. A window
  crossing midnight belongs to the day it starts. The cycle counts real days, so with
  everyDays 2 it is strictly alternate days: after a 31st it does not follow odd /
  even dates.
• The clock. Leave Clock unwired to use the controller clock. It is UTC, so set
  utcOffset for local time. Daylight saving isn't automatic: change utcOffset
  (or wire a local-time clock).
• Clock fault. ClockOk is off when the clock is before 2020 or from 2100, or hasn't
  moved for 5 s. The schedule is then off (Active off, Window 0) until the clock is
  good again. An operator override still works.
• Pulses. HourPulse and DayPulse are in local time. A clock set forward gives one
  of each, however far. A clock set back (daylight saving, a correction) never pulses an
  hour or day twice; set back by more than an hour (a day), the block follows the new time.
• Override. cmdOverrideOn / cmdOverrideOff hold Active on / off for
  overrideFor, then the schedule takes over again. With overrideFor = 0 the override
  lasts until the schedule next switches. If several commands arrive together, Off wins,
  then Cancel over On. Each command acts once and is cleared; a command held on (a Modbus
  coil, a debugger force) acts only once, so an override still ends.
• nextChange is worked out once a second, looking up to 8 days ahead (a window
  every 9 days or more may show "never" until it is within 8 days). nextChangeIn
  counts down to it, for an HMI countdown.