UT_TOTALISER — Totals from any source (flow, energy, production, runtime)

Accumulates a quantity from whatever the field gives you. Choose the method for
the meter you have; everything else (periods, interval records, batch target, rate
output, units, retention) works the same for every method.

Pins

Which meter, which method

Methods — countMethod : UT_TOTAL_METHOD

COUNT or REGISTER? A counter that starts again from 0 when its device restarts is
COUNT. A meter that keeps its own total through a power cut is REGISTER (a drop
there is a glitch or a meter swap, never a restart from 0).

Units

inUnit is the unit of pulseValue, of the register or count quantity, of the
rate on Value and of nominalRate. outUnit is the unit of every total, of the
interval record and of Rate. When both are set, every addition and the rate are
converted; when either is UT_VOL_NONE (the default) nothing is converted.

Example: a meter giving 1 pulse per 10 L, totals in m³: pulseValue := 10.0,
inUnit := UT_VOL_L, outUnit := UT_VOL_M3. Each pulse adds 0.01 m³.
A 4–20 mA transmitter scaled in L/s, totals in m³: rateUnit := UT_PER_SEC,
inUnit := UT_VOL_L, outUnit := UT_VOL_M3; Rate is then in m³/s.
scale still multiplies on top (meter calibration). lowCutoff, maxStep and
rolloverAt stay in the units of Value.

Interval records

Every interval (default 15 minutes) the block writes one record for the IoT
platform and sets IntervalDone for one scan:

The fields hold until the next record; only IntervalDone is one scan.

• With Clock: intervals end on whole multiples of interval since midnight
  (15 min: :00, :15, :30, :45), and intervalEnd is that boundary time. The first
  interval after power-up is a part interval (it starts at power-up). A clock jump
  forward closes one record covering the gap; a clock set back closes nothing.
• Without Clock: intervals are counted from power-up, every interval of
  running time, and intervalEnd stays at DT#1970-01-01-00:00:00. Let the platform
  time-stamp the records.
• interval := T#0s switches the records off. Changing interval starts again.
• The records are not kept over a power cut: intervalSeq starts at 0 again.
  The platform stores the history and works out monthly figures.

Record UT_TOTAL_DATA

Settings

Commands

• HMI: cmdResetBatch, cmdRollover.
• Admin or technician only, through the platform; never on an operator HMI:
  cmdResetTotal (resets total, totalIn, totalOut; needs cmdConfirm in the
  same write), cmdConfirm, cmdPreset + presetTotal (0 to 1E12; anything else
  is ignored). The block cannot check who wrote them: keep them out of operator
  screens.

Each command acts once and is cleared.

Status

Compliance metering

• Counting in the PLC (PULSE or COUNT): the total lives in the PLC, so set a short
  saveEvery, for example T#1m. A power cut then loses at most that much counting.
• REGISTER reads the meter's own total, so the meter keeps counting while the PLC is
  off and nothing is lost.
• The platform logs the interval records.
• NZ regulations require 15-minute records, sent daily, for takes of 5 L/s or more.

Notes

• Power cut: kept as of the last save (saveEvery; resets, presets and user
  rollovers at once): every total and period total in the status table, with the
  hour and day they belong to, the snapshots and the register or count reading, so
  nothing is counted twice. After the restart REGISTER counts what the meter recorded
  while the PLC was off; COUNT counts a counter that restarted from 0 (or kept
  counting). Not kept: the interval records, pulses and rejectedSteps (start at
  0), the warnings.
• Totals are kept in millionths of a unit in 64-bit integers, plus the part of a
  millionth left over, so they stay exact on every board (LREAL is only 32-bit on some small boards).
  A total of 10 000 000 still counts single units.
• Pulses are seen once per scan: the maximum is one pulse per two scans (half the
  task rate, e.g. 50 Hz at 10 ms). wrnPulseTooFast is raised at that limit. Count
  faster meters outside the scan and use COUNT.
• COUNT: the count is a UDINT on Count, exact at any reading (a REAL would lose
  single counts past 16 777 216). Leave rolloverAt at 0 for a 32-bit counter.
• A counter that restarts close to rolloverAt looks like a wrap. maxStep limits
  what such a step can add.
• Hour and day totals follow the clock's hour and day changes, also after a power
  cut that spanned midnight or a month end (the day before the cut becomes
  yesterday). A jump of more than one hour or day leaves the skipped period at 0;
  a clock set back closes nothing and never makes a negative period. Wire a
  local clock: the runtime's CURRENT_DT is UTC.
• After a restart, REGISTER counts what the meter recorded while the PLC was off,
  also when the reading is 0 for a while (comms down) before or after the cut.