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UT_STARTS — Start counter and restart inhibit

UT_STARTS — Start counter and restart inhibit

Counts starts, and protects motors from starting too often: a maximum number of
starts per hour, a minimum time between starts, and a longer wait after a failed
start. Starting current heats the windings, so too many starts in a short time
damages a motor. Wire StartPermit to the motor's Permissive.

Pins

Pin Type Default What to wire
in Running BOOL FALSE Motor running (each rising edge = one start)
in StartFailed BOOL FALSE Rising edge: a start attempt failed (e.g. Motor1.noFeedback.tripped)
in Reset BOOL FALSE Rising edge: clears the inhibit (not the counters)
out StartPermit BOOL → motor Permissive
out Starts UDINT Lifetime starts
out PermitIn TIME Time until the next start is allowed
inout Data UT_STARTS_DATA

Record UT_STARTS_DATA

Field Type Default Meaning
saveEvery TIME T#12h How often the counts are saved for a power cut (T#0s = not kept). Presets, count resets and day rollovers are saved at once
maxPerHour INT 0 Starts allowed within window. 0 or negative = unlimited, above 30 = 30. Use the motor maker's figure
window TIME T#1h The sliding window maxPerHour counts over (0 = off; longer than 24 days counts as 24 days)
minBetween TIME T#0s Minimum time from one start to the next (longer than 24 days counts as 24 days)
failWait TIME T#0s Wait after a failed start (longer than 24 days counts as 24 days)
cmdReset BOOL HMI: clear the inhibit (not the counts)
cmdResetCount BOOL HMI: lifetime count to 0
cmdPreset + presetStarts BOOL + UDINT HMI: set the lifetime count (a preset in the same write as a count reset wins)
cmdDayRollover BOOL Midnight pulse: today → yesterday
total UDINT Status: lifetime starts
lastHour INT Status: starts within the window now (shows at most 30)
startPermit, permitIn BOOL, TIME Status: as the pins
todayStarts, yesterdayStarts UDINT Status

How it works

  • The next start is allowed at the latest of: the last start + minBetween, the
    last failed start + failWait, and, when maxPerHour starts are in the
    window, the oldest of them + window. The window slides: each start drops out
    exactly window after it was made.
  • The block keeps the time of each of the last 30 starts as milliseconds on its own
    clock, which counts from its first scan. So window, minBetween and failWait
    can be at most 24 days: a longer setting counts as 24 days.
  • The permit never stops a running motor: StartPermit stays TRUE while
    Running is TRUE, whatever it is wired to. A start made anyway (Hand, hard
    wiring) is still counted.
  • A motor already running when the block first runs is not counted as a start.
  • Power cut: the counts (lifetime, today, yesterday) are kept as of the last
    save (saveEvery; presets, count resets and day rollovers at once). The
    inhibit is not kept: after a power-up the window is empty and a start is
    allowed at once.
Last updated 2 hours ago
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