The HRI-Mei is a data capture device for MeiStream and MeiTwin MID bulk water meters. All MeiStream standard registers are prepared to receive the HRIMei. The HRI-Mei can also be mounted afterwards without breaking the meter’s seal.


The HRI-Mei provides a high resolution pulse output with water flow direction detection.

Also, the data interface can be used for M-Bus applications.

With the HRI-Mei all known data interfaces with Encoder, Electronic and Hybrid registers can be replaced.

Depending on the register a second pulser like the Opto OD can be plugged in additionally e.g. at the MeiStream.

Also, other applications requiring reed switches or optical pulse outputs can be supported with only this one data capture device.

Our HRI-Mei sensor reading device is a data interface for pulse output for industrial water meters. It provides a high-resolution pulse output with a flow direction signal. The data interface can be used for M-Bus applications.

Designed for industrial water meters like MeiStream and MeiTwin, the HRI-Mei can be retrofitted without breaking your meter’s metrological seal. It is also built to withstand harsh environments, like flooded pits.

You can use the HRI-Mei for:

  • Industrial monitor and control applications and SCADA systems
  • Flow rate indication using frequency converters like FM-1D/K or FM-2D/K
  • Local meter reading for billing applications
  • Meter remote reading and profiling via cable fixed networks with M-Bus, radio modem or GSM network
  • Data logging in conjunction with various data loggers (i.e., CDL)

Benefits to you

  • Is compatible with commercial and industrial water meters like MeiStream and MeiTwin
  • Clips onto an appropriate water meter without breaking the meter’s seal
  • Detects water flow direction
  • Supports other applications requiring reed switches or optical pulse outputs
  • Accommodates a second pulser (depending on the register)


  • Load-free, inductive scanning of the meter’s pointer
  • Self diagnosis and tamper detection
  • Battery lifetime up to 12 years, extended with external power supply (i.e., a M-Bus central unit)
  • Sturdy construction and sealed housing (IP68)
  • 3-meter cable


Pulse Output:

  • Electronic pulse output with no switch bouncing
  • Pulse weight and length can be changed on-site
  • Different modes for pulse output, tamper output, direction output

Data Interface:

  • M-Bus and MiniBus (autodetected)
  • Automatic detection of baud rate (300/2400Bd) and type of interface
  • Data protocol according to IEC870-5/EN13757-3
  • Provides an easy-to-use data protocol compatible with the encoder registers
  • Transferred data
    • Meter index
    • Fabrication number
    • Meter ID equivalent to secondary address
    • Monthly meter index for programmable day
    • Meter index for programmable yearly key date and for the year before
    • Min./max. water flow with date/time
    • Backward water volume with date/time
    • Broken pipe and leakage detection with programmable flow thresholds
    • Tamper detection (*)
    • The HRI-Mei can be programmed to transfer selected information.

Programmable Data:

  • All changeable data can be set with MiniCom software via the M-Bus / MiniBus data interface.The MiniCom download is free of charge.

(*) Requires tamper target at the meter.

Pulse Modes

The HRI-Mei provides 4 different pulse output modes via 2 lines.

Parallel usage of the pulse output and serial output is not recommended and may cause problems depending on the application.

Mode B2:

I1: Forward pulses

I2: Backward pulses

Mode B3:

I1: For-/Backward pulses

I2: signal for the flow direction (1)

Mode B4 (default):

l1: balanced pulses

l2: Alarm (opens when there is an alarm or cable cut)

Mode B5:

Opto-OD (NAMUR) pulse output (6 ms)

I1: pulses with flow direction code

I2: not used

Temperature range:

HRI-Mei standard for cold water (30 °C) and warm water (50 °C).

Environmental temperature range: -10 °C to +60 °C

Programmable Pulse Weights

(10, 25,....10000) litre/pulse

Pulse length

32, 128 or 500ms

Max. Voltage

48 Vdc

Max. Current

0.2 A

Max. Switching Capacity

4 W


HRI-Mei Datasheet