UT_PULSE_SEQ — Sequential pulsing (jet-pulse filters, flushing, staged outputs)

Pulses a row of outputs one after another: dust-collector cleaning valves,
irrigation flush valves, staged heaters. It can run continuously or on demand
(e.g. while the filter differential pressure is high), with post-clean cycles after
stopping. Any number of channels. Never more than one output is on.

Pins

Channels count from 1 = the first element, whatever the array's lower bound.

Record UT_PULSE_SEQ_DATA

How it works

• Each channel gets pulsesPerChannel pulses of pulseOn with pulseOff between
  them, then channelGap before the next channel. After the last channel CycleDone
  pulses and, while cleaning is still wanted, cyclePause passes before the next cycle.
• Cleaning is wanted while Enable AND Demand, after startDelay. When that ends:
  postCycles = 0 stops at once (an output that is on goes off); postCycles > 0
  finishes the cycle and runs that many more full cycles, even with Enable off
  (off-line cleaning after the fan stops). Demand coming back during the post-clean
  simply carries on cleaning.
• Hold turns the output off; on release the interrupted pulse is given again in full
  on the same channel. Gaps and pauses keep their remaining time.
• With every channel skipped nothing runs (no CycleDone).
• Each phase lasts at least one scan, so a pulse shorter than the scan lasts one scan.
• Nothing is kept over a power cut: every output is off, and cleaning starts again
  from channel 1 when wanted.

Status codes

statusCode is a UT_STATUS and faultId a UT_FAULT (an HMI reads their numbers);
statusText is the two in words, changed only when one of them changes. The one main
thing, in the order config, held, warning, normal, idle. channel, pulse and
timeLeft (the phase's time left) say where it is.

Bad settings

Invalid settings warn (configBad) and use safe values: a negative time acts as 0
(pulseOn one scan), pulsesPerChannel below 1 as 1, postCycles below 0 as 0.