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HWg-PWR 3/12/25: Smart M-Bus to Ethernet gateway

HWg-PWR is a smart Ethernet gateway for remote energy metering and consumption monitoring. To measure the consumption of water, electricity and other energies, external meters with the M-Bus interface are used. Up to 3 / 12 / 25 M-Bus meters can be connected to the HWg-PWR unit. Individual meters (electricity meter, water meter, gas meter, heat meter etc.) are produced by third parties and connected via their M-Bus interface. HWg-PWR is a smart gateway that monitors energy consumption and warns about abnormal values The unit provides a Web interface, charts, SNMP and Modbus/TCP output, data logging, e-mail and SMS alerts, and much more.

HWg-PWR 3/12/25 monitors energy consumption using standard external energy meters produced by well-known manufacturers. It is possible to mix electricity meters, water meters, gas meters etc. by different manufacturers. Depending on version, HWg-PWR supports 3, 12 or 25 external meters with the M-Bus interface (EN 13757).

HWg-PWR 3 / 12 / 25 – Energy monitoring gateway:


Advantages of using third-party M-Bus meters

  • Vast range of meters with the EN 13757 (M-Bus) interface to choose from.
    It is easy to use special-purpose meters (non-standard form factor or measured range, e.g. indirect electricity meters rated up to 1000 A).
  • M-Bus meters frequently provide extended information (total consumption and immediate values, voltage at different phases, power factor, etc...).
  • Values from certified meters can be used for billing purposes.
HWg-PWR: Ethernet energy meter

HWg-PWR 3   HWg-PWR 12   HWg-PWR 25

photo4  photo5  photo6  photo7

Application photo

HWg-SMS-GW3 for sending SMS


  • Ethernet: RJ45 (100 Mbit)
  • WEB: Built-in Web server, charts
  • Data input: 3 / 12 / 25 external meters equipped with the M-Bus (EN 13757-2) interface
    • M-Bus power: Meters powered from HWg-PWR
    • M-Bus standards: EN 13757-2 (physical layer) & EN 13757-3 (application layer)
    • Variables (data points): Up to 100 different variables from all (max. 25) meters
    • M-Bus: Automatic detection of meters and available values
  • Digital inputs: 8x Digital Input for 110/230V phase failure detection (senses tripped circuit breakers)
  • Data logging: 170,000 values (3 values every 15 minutes = 590 days)
  • Power: 110 or 230V AC
  • Mechanical: Fits on a DIN rail
  • M2M communication protocols: SNMP, XML, Modbus/TCP
  • Response to thresholds: SNMP trap, E-mail, SMS (via SMS-GW)
  • Portal: HWg-Push protocol, supports

  • Graphs: Logging of values with the option to plot graphs
  • Counter: Independent counter for periodic consumption readouts (daily, weekly, monthly, annually, ...)
  • Report: Periodic e-mailing of measured values
  • SMS Gateway: Device can send SMS by external "HWg-SMS-GW" without any software.
  • Support for programmers: HWg SDK
  • Supported software
    • HWg-PD Trigger: Control of other IP devices, alarm redirection to SMS
    • HWg-PDMS: Logging, export to MS Excel
    • >> Third-party SNMP software
      (HP OpenView, IBM Tivoli, Nagios, Zabbix, Cacti, Monitor one, The Dude, Paessler IPCheck, Ipswitch WhatsUp, Axence nVision, CBR little:eye, LoriotPro, GFi NSM, SNMPc 7, CA NSM, ActiveXperts NM, Intellipool NM, MSC Operations Manager 2007)
  • HWg-PWR demo boxExternal M-Bus meters (third-party products)
    • Values available over M-Bus depend on the meter – we recommend to always check the supported values with the manufacturer!
    • Support for certified and calibrated meters
    • Support for single-phase and polyphase electricity meters
    • Support for single-tariff and multi-tariff meters
    • Current transformers enable measurements of high currents
    • Examples of typically available values:
      • Instantaneous power input
      • Total consumption
      • Line voltage
      • Line current
      • Power factor (cos φ)
      • Flow speed
  Inputs Power  Web  M2M outputs
M-Bus meters M-Bus variables Digital inputs Modbus/TCP
SMS GW E-mail E-mail report HWg-Push
HWg-PWR 3 3 Max 100 8x 110/230VAC 110/230VAC
HWg-PWR 12 12 Max 100 8x 110/230VAC 110/230VAC
HWg-PWR 25 25 Max 100 8x 110/230VAC 110/230VAC *
Old model – no longer in production
3 Max 30 3x Dry Contact 230V - - -


M-Bus or S0 pulse counter

S0 is a legacy system of counting pulses that correspond to a certain amount of energy.
The M-Bus interface is the current standard for energy metering. Unlike pulse counting (S0), it works with absolute values (that can be used for customer billing). In addition, M-Bus provides more values, such as the immediate current and voltage, cos φ, and so on.

An S0 to M-Bus converter can be used to connect S0 devices:


M-Bus meter manufacturers

Caution: We recommend to always check and test what values does the manufacturer guarantee at the M-Bus interface.

Gas meters

Water meters
Heat meters
Electricity meters
Other accessories
ABB - - - TESTED -
AllMess - - -
Aquametro - - -
Bmeters - - - -
Carlo Gavazzi - - - -
Elster - - - -
Elvaco - - - TESTED
EMH - - - -
EMU - - - -
Günther Schell - - - - TESTED
GMC-I - - - -
IME - - - -
Inepro / DMMetering - - - -
ista - TESTED - -
Itron -
Janitza electronics - - - -
Kamstrup - -
Křižík - - - -
Landis + Gyr TESTED TESTED -
Metec/DZG - - - -
Meters UK - - - -
SagemCommunications - - - -
Saia Burgess - - - TESTED -
Sensus - - -
Sontex - - - -
TIP Thüringer - - - -
WDV/Molliné - - -
WEHRLE - - - -
ZPA - - - TESTED -




  • Remote monitoring of electricity meters in small server rooms and BTS
  • Monitoring of energy consumption in rented premises
  • Reading out energy consumption in remote or inaccessible areas
  • Control over energy costs
  • Checking for individual line overloads in three-phase wirings
  • Checking for undervoltage in electric wirings
  • Monitoring the flow of liquids

Collecting data from 1 to 25 M-Bus electricity meters

  • Various energy meters (equipped with the M-Bus interface) are connected to the HWg-PWR unit.
  • All values are available to external software over LAN and SNMP.
  • Energy consumption details can be viewed using the Web interface or an iPhone or Android app.

Server room: Energy consumption monitoring + phase outage detection

  • Up to 25 electricity meters measure the single-phase or three-phase consumption of the cabinets.
  • Up to 8 inputs can detect phase outages.
  • When a phase fails, a warning can be e-mailed.
  • Upon an alarm (phase failure or current out of range), a text message alert can be sent to a mobile phone via an external SMS Gateway.
  • Energy consumption data can be connected to any SCADA system (Modbus/TCP) or accessed over SNMP.

Measuring energy consumption with S0 pulses and M-Bus meters

  • Modern electricity meters with the M-Bus interface can be connected to HWg-PWR directly.
  • Older electricity meters with a S0 pulse output can be connected using a “S0-M-Bus” converter.
  • Current consumption charts are available through the HWg-PWR web interface.
  • Every day, week or month, HWg-PWR e-mails a report. The e-mail contains a billing statement including KWh and a conversion to currency.
  • When the current consumption exceeds or drops below a set threshold, the unit sends an e-mail alert.

Remote energy metering with a central WEB portal

  • Various energy meters are connected to a single HWg-PWR unit.
  • Each unit has a WEB interface for configuration, viewing logs, etc.
  • All consumption data are uploaded to a central portal using the HWg-Push protocol.
  • The central portal (e.g. SensDesk) generates detailed analyses and statistics concerning energy consumption.



OID Description
HWg-PWR 3 Smart Ethernet gateway for connecting 3 M-Bus meters to a LAN.
HWg-PWR 12 Smart Ethernet gateway for connecting 12 M-Bus meters to a LAN.
HWg-PWR 25 Smart Ethernet gateway for connecting 25 M-Bus meters to a LAN.
HWg-PWR 3 mobile box Demonstration mobile solution for HWg-PWR 3 - photo.
Mobile box can be used as temporary 1 phase (230V) meter.
HWg-SMS-GW3 HWg-SMS Gateway start set
GSM SMS gateway for sending text messages from other HW group devices over the LAN. Includes an internal GSM modem, an external antenna with 3m cable, a power adapter and a CD. - photo

M-Bus meters supplied by HW group

We recommend to order M-Bus meters directly from the respective manufacturer's distributor for your local market.
The following M-Bus meters are produced by third parties. HW group offers these meters to simplify your first steps.
  • Meter 3f ED 310.DB HWG
    ED 310.DB HWG is a static three-phase, two-tariff electricity meter for direct measurement up to 63A, with M-Bus and S0 interfaces – 3x230V/400V, 5(63)A
  • Meter 3f ED 310.I.DB HWG
    ED 310.I.DB HWG is a static three-phase, two-tariff electricity meter for indirect measurement, with M-Bus and S0 interfaces – 3x230V/400V, x/5A
  • Meter 1f DHZ 5/63-M-BUS – Single-phase electronic electricity meter for direct measurement up to 63A.
  • Meter 3f ZMF120ACs2 M-Bus – three-phase electricity meter without a disconnecter, direct up to 40A.
  • Meter 1f ZCF120ABs2 M-Bus – single-phase electricity meter with a disconnecter, direct up to 40A.
  • Meter gas G350 M-Bus – L435 M-Bus gas meter, with 250mm pipe spacing and G1¼ ISO 228-1 class B.
  • M-Count 2C – 2x S0 datalogger and converter to M-Bus (2x pulse input (S0) / M-Bus output)
  • CLA 3.1 – Current measurement transformer, 1000A/5A, accuracy class 0,5S, power 10VA
  • CLB 2.65 – Current measurement transformer, 200A/5A, accuracy class 0,5S, power 10VA
  • We will be happy to help you with selecting other M-Bus accessories.

Ordering and FAQ

    Ask for the price or details:
     - Web:  http://
    Country: *

    Spam protection. How many is SIX times six?

  • How many M-Bus meters can I connect to the HWg-PWR smart gateway?

    You can connect max 3 M-Bus meters (devices) to the HWg-PWR 3.
    You can connect max 12 M-Bus meters (devices) to the HWg-PWR 12.
    You can connect max 25 M-Bus meters (devices) to the HWg-PWR 25.

  • What values can HWg-PWR display?
    HWg-PWR can display any values and quantities that are accessible over M-BUS from the respective meter.
  • Is it necessary to use meters supplied by HW group?
    No. Any device from any (third-party) manufacturer can be connected to HWg-PWR, as long as it has the M-Bus interface.
    To help you choose, we have compiled a list of tested meters. See the link in the Download box.
  • How many different variables can be monitored?
    HWg-PWR 3 / 12 / 25 supports a maximum of 100 variables. The particular combination is not relevant, e.g. 25x4 (25 meters x 4 variables each) or 10x10 variables are possible.
    Each variable can be logged and monitored by e-mail.
  • Is it possible to use electricity, water and gas meters from different manufacturers on a single bus?
    Yes, as long as the devices use the same communication speed (typically 2400 b/s)
  • How far away can be the M-Bus meters from the HWg-PWR unit?
    At 300 Bd, the cable segment length must not exceed 1000 m (max 350 m at 9600 Bd).
  • Is it possible to connect Wireless M-Bus meters to HWg-PWR?
    Not directly. The HWg-PWR smart gateway supports wired M-Bus only. However, we have successfully tested a wireless-to-wired M-Bus converter.
  • Where can I find the prices of your devices?
    Ask our distributors, or request a quote directly from us using the form at this page.
  • What is the warranty?
    The standard warranty is 2 years, can be extended upon request.


HWg-PWR, M-Bus gateway, Mbus IP, M-Bus EN 13757-2, MBus Ethernet, EN 13757-3, M-Bus electricity meter, M-Bus logging, electrical energy metering, electricity meter,
gas meter, heat meter, M-bus, SNMP, modbus/tcp, HWg-push, web, graphs, charts

Similar and related products

  • Software: HWg-PDMS (Collects data to a database, displays graphs, exports data to MS Excel)
  • Damocles Family – Ethernet I/O products with S0 counters at the inputs


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