Integration and instrumentation

Pulse meter remote monitoring

A counter on the meter's existing pulse output, the pulse weight recorded once, and a totaliser reading that lets you prove the counts later.

ZPC-20 Pulse Counter
ZPC-20Pulse counting
ZGW-20 Gateway
ZGW-20Gateway with Edge
Measure
The counted pulses, the meter's own totaliser at the start, and the engineering-unit total derived from both
Scale
Battery models count to 4 Hz, mains models to 40 Hz, one or two channels ZPC-2X datasheet (PDF, opens in a new tab)
Sensors
ZPC-20, pulses down to 10 ms wide, up to 40 Hz, inputs to 35 V DC ZPC-2X datasheet (PDF, opens in a new tab)
On site
ZGW-20 Gateway, unit conversion, water meter pulse counter totals and reconciliation ZGW-20 datasheet (PDF, opens in a new tab)

Hardware for pulse output meter reading

The choice is made by the pulse rate and by whether there is power at the meter.

What has to be recorded before the first pulse

A pulse count means nothing on its own. These four records are what turn it into consumption you can defend.

What has to be recorded before the first pulseThe counter sits at the meter and the Gateway does the arithmetic, so a change of pulse weight is a configuration change and not a rewired meter. Existing equipment Modbus meters M-Bus heat meter Pulse meter 4-20 mA transmitter RS-485 M-Bus Pulse Loop Interface Interface Interface Interface ZGW-20 Edge on site BMS, SCADA or platform Modbus TCP ZPC-20 ZGW-20 What has to be recorded before the first pulseThe counter sits at the meter and the Gateway does the arithmetic, so a change of pulse weight is a configuration change and not a rewired meter. Modbus meters M-Bus meter Pulse meter 4-20 mA Interface Interface Interface Interface ZGW-20 Edge on site BMS or platform ZPC-20 ZGW-20
The counter sits at the meter and the Gateway does the arithmetic, so a change of pulse weight is a configuration change and not a rewired meter.
Sensor positions for what has to be recorded before the first pulse
PositionWhat it tells youReferenceSensor
Meter totaliser The reference every later reconciliation is measured against Photograph the display with the date and time before connecting anything ZPC-20 (on this page), recorded, not counted
Pulse weight How much water, gas or energy one pulse represents From the meter's plate or manual, exactly as configured on the meter ZPC-20 (on this page)
Electrical output Whether the output is a dry contact or an active voltage, and how fast it can go Voltage, polarity, pulse width and maximum rate from both manuals ZPC-2X datasheet (PDF, opens in a new tab) ZPC-20 (on this page), before wiring
Counter behaviour What happens at a reset, a rollover or a reporting gap Counter width, persistence and how duplicates are reconciled ZPC-2X datasheet (PDF, opens in a new tab) ZGW-20 (on this page)
  • Two terminals are not proof of a dry contact. An active output can put a voltage on the same pair. Check the meter's manual or measure before connecting, because the wrong assumption damages something.

  • A fast meter needs mains. The battery counters take 4 Hz and the mains counters 40 Hz. Work out the maximum rate from the process rate and the pulse weight before choosing.

Pulse settings that have to match the meter

All of these come from the meter. None of them can be inferred from a plausible-looking trend.

Pulse settings that have to match the meter
SettingTypical valueWhere to check
Output type Dry contact, or active voltageThe meter's manual. An active output has its own voltage and polarity.
Pulse weight 10 litres or 0.1 m³ per pulseThe meter's plate, and the meter's own configuration where it is settable.
Minimum pulse width 10 ms or widerThe counter's limit is 10 ms, with at least 10 ms between pulses.
Maximum rate 4 Hz battery, 40 Hz mainsCalculate it from the maximum process rate and the pulse weight before choosing the model.
Input voltage Up to 35 V DCThe meter's output specification, measured if the manual is missing.
Counter rollover Handled in EdgeThe counter's width, and what the reconciliation does when it wraps.
Reporting interval 15 minutesEdge sensor settings. Counts accumulate between reports rather than being lost.

Commissioning checks

The order matters: the totaliser reading has to exist before the counting starts.

  1. Record the meter as found

    Photograph the display, and write down the serial number, the pulse weight, the units and the time.

    Pass when the record identifies one meter and one starting total.

  2. Check the output electrically

    Confirm the output type, voltage, polarity and pulse width against both manuals, or measure them.

    Pass when the meter's output is inside the counter's input rating, with the polarity known.

  3. Count a known number of pulses

    Generate or observe a known quantity through the meter and read the raw count.

    Pass when the remote count changes by exactly that number of pulses.

  4. Interrupt the radio deliberately

    Take the Gateway off the network for longer than the reporting interval, then bring it back.

    Pass when the counts for that period arrive afterwards, in order, with nothing double counted.

  5. Reconcile against the totaliser

    After a bounded period, read the meter's display again and compare it with the derived total.

    Pass when the two agree within one pulse, and any reset or rollover is documented.

What this measurement does not tell you

Counting a meter's pulses does not change the meter, and does not make it more approved than it was.

  • Reading a pulse output does not alter or certify the utility meter, its tariff multiplier or its legal-metrology status.
  • Electrical compatibility comes from documentation or measurement: a two-wire terminal is not automatically a dry contact.
  • A short matching test does not rule out contact bounce, missed edges, a meter reset or a long-period clock fault.
  • A derived consumption is only as good as the pulse weight somebody wrote down.

Sources and related guides

Sources

Related

Reviewed by EpiSensor Engineering on . Revision 4.

Confirm a meter's output before you buy a counter

We will confirm the output type and the rate, pick the counter, and write down the pulse weight with you.

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