Skip to main content Skip to search Skip to main navigation

Perseus Energy 242

The LAN solution for energy monitoring with M-Bus Master

The HW group Perseus Energy 242 is a LAN solution in a metal housing for remote monitoring and control in the field of energy monitoring, equipped with an M-Bus Master. It connects external physical sensors (°C, %RH, A, V, …), detectors (relay/dry contact) or a WLD sensor cable (water leak detection). Third-party meters can additionally be connected via LAN or Modbus/RTU.

The Perseus Energy 242 combines data from external physical sensors/detectors/meters with data from other HWg devices connected via the network. Local conditions, Lua scripting, a calendar or a periodic scheduler help evaluate the measured data – with a capacity of up to 100 meters (sensors) with 1,000 values (variables).

Sensors, M-Bus meters and other network devices in one system

In a metal housing, the Perseus Energy 242 combines four 1W-UNI ports (RJ11), two digital inputs (DI) with S0 pulse counters, RS-485 (Modbus/RTU), a WLD zone connection as well as an M-Bus Master input and a relay output (DO).

🔌

4x RJ11 (1-Wire UNI)

Up to two HW group 1-Wire UNI sensors per port, e.g. for temperature, humidity, voltage or current.

📟

M-Bus Master

One terminal block for the direct connection of M-Bus-compatible meters, such as electricity, gas or water meters.

🧾

RS-485 (Modbus/RTU)

4-pin terminal block with 12V for connecting Modbus/RTU-capable third-party sensors and meters.

💧

WLD water leak detection

1 zone for an external water sensor cable with a total length of up to 185 m.

🔗

2x DI (S0) / 1x DO

Two digital inputs with S0 pulse counters for energy meters and one relay output for controlling e.g. ventilation or doors.

🌐

Meters API

Additionally reads sensor data from other HWg and third-party devices on the same LAN (SNMP, Modbus/TCP, MQTT, HWg XML).

Individually selectable: base unit or starter set

The Perseus Energy 242 is available either as a pure base unit or as a complete starter set with 24V power adapter. The desired option must be selected in the shopping cart.

⚠️

Please note: The Perseus Energy 242 requires an external 24 V power supply. The base unit "Perseus Energy 242" does not include a power supply unit. Only the "Perseus Energy 242 set" variant includes a 24V EU power adapter with 2-pin plug. The option must be selected in the shopping cart.

Perseus Energy 242

Perseus 242 device. GW energy meter: metal housing, M-Bus, RS485 Modbus-RTU, meters API. Requires external 24 V power supply; power supply unit is not included.

Perseus Energy 242 set

Perseus 242 energy GW starter set. Includes: Perseus Energy 242 as above plus a 24V EU power adapter with 2-pin plug.

How the Perseus Energy 242 is designed

The robust metal housing is designed as a DIN-rail device measuring approximately 35 x 111 x 140 mm (W x H x D), with IP40 protection rating and designed for operating temperatures from -30°C to 85°C.

1

Metal housing for DIN rail

Robust metal housing that can be mounted on a desk, in a rack or on a DIN rail – suitable for IT, SoHo and industrial environments.

2

Ethernet connection with web server

One RJ45 Ethernet port (100BASE-T) connects the device to the network; an integrated web server enables configuration directly via the browser.

3

Sensor and meter connections

Four RJ11 ports for 1-Wire/1-Wire UNI sensors, one RS-485 terminal block (including 12V) for Modbus/RTU and a separate M-Bus Master terminal block for M-Bus meters.

4

WLD, DI and DO terminals

One WLD zone connection for the water leak sensor cable (A/B), two terminals for digital dry contact inputs with S0 pulse counters and one relay output (up to 50V/1000mA) for controlling external actuators.

5

Power supply (24V)

The Perseus Energy 242 is supplied exclusively via a terminal block with 24V DC; the terminal block also provides a 24V output for external devices. A matching 24V EU power adapter is only included with the "set".

6

Status indicators

LEDs on the front of the device indicate, among other things, status, alarm and WLD condition.

Evaluate sensor data from other LAN devices as well

The Meters API is a unique feature of all Perseus products: the device additionally reads sensor values from external LAN devices and includes them in analyses and alarms.

  • Readable protocols: HWg XML, Modbus/TCP, SNMP, MQTT
  • Examples of supported third-party devices: STE2 LITE, Poseidon2 4002, Damocles2 1208, NETIO PowerPDU 8QS, SNMP-capable UPS systems
  • Combination of RS-485, M-Bus Master and Modbus RTU Meters API allows reading of third-party electricity, gas and water meters, UPS or climate devices
  • Comparison of multiple sources possible, e.g. own 1-Wire temperature sensor vs. external thermometer vs. UPS temperature sensor

In addition, the Perseus Energy 242 supports integration into building automation systems via BACnet/TCP as well as IPv6 for modern, future-proof network environments.

Notification of critical events

The Perseus Energy 242 offers both local and network-based alarm options.

Local alarms

Switching of the relay output (DO) based on sensor data, e.g. to activate ventilation, air conditioning or automatic doors.

Standalone device alarms

SNMP trap and e-mail directly from the device (SMTP server required); SMS and call alarms can be realized via an external SMS gateway (e.g. SMS-GW3).

Portal alarms (SensDesk)

Additionally e-mail, SMS, voice calls, device failure alert (Device Invalid Alert), alarm escalation and PDF reports.

Advanced conditions

Alarms can be configured, for example, so that they only trigger when 2 out of 5 sensors exceed a threshold or are unreachable.

Lua scripting, conditions and schedules

For individual evaluation logic, the Perseus Energy 242 includes several tools.

  • Local, user-defined scripts in Lua
  • Variables with multiple conditions and actions
  • Calendar- or period-based scheduler
  • Template repository for third-party sensors
  • Virtual sensors as well as unit conversion and calibration offset
  • Integrated logger with 32 MB memory

Secure authentication and encryption

  • Radius authentication according to IEEE 802.1X
  • HTTPS with customer certificate
  • Admin and user accounts with separate access rights
  • IPv6 support as well as SNMP v1 and v3 (including SNMP traps)

From free cloud access to your own portal instance

The Perseus Energy 242 can optionally be connected to the SensDesk portal and thus expanded with central evaluation and management functions.

HWg-cloud.com

Free portal service with e-mail alarms, device failure alert and a value graph with short history.

SensDesk.com / Portal Provider

Paid portals with e-mail, SMS and voice call alarms, virtual sensors, multi-graphs over several years, PDF reports and multi-user accounts.

Portal On-Premise

Standalone SensDesk installation on your own server for companies with special data protection requirements.

HWg Monitor App

Mobile app for iOS and Android, displays all sensor values at a glance – also usable as a wall display in the technical room.

Commissioning in a few steps

Setting up the Perseus Energy 242 is done entirely via the web browser.

  1. Mount the device on a desk, in a rack or on a DIN rail
  2. Connect the 24V power supply (power adapter already included with the "set")
  3. Connect the device to the network via Ethernet cable
  4. Open the device’s IP address in the browser (initial search possible e.g. with HWg-Config)
  5. Connect 1-Wire UNI sensors to the RJ11 ports, Modbus/RTU devices to the RS-485 terminal block or M-Bus meters to the M-Bus Master
  6. Optional: Wire the WLD sensor cable, dry contacts (with S0 pulse counters) and the relay output
  7. Optional: Configure alarm rules, Lua scripts or the connection to SensDesk/HWg-cloud.com

Why the Perseus Energy 242 is the right choice

M-Bus Master

Direct connection of M-Bus-compatible electricity, gas and water meters.

Versatile sensors

4x RJ11, RS-485, M-Bus, WLD, DI/DO in one device.

Meters API

Additional evaluation of sensor data from other LAN devices.

Open standards

SNMP, Modbus/TCP, MQTT, XML and BACnet/TCP.

Robust metal housing

Designed for operating temperatures from -30°C to 85°C, DIN-rail compatible.

24 months warranty

According to the manufacturer with 24 months warranty from the date of purchase.

Practical application examples

  • Data concentrator for all local sensors and meters at a site
  • Remote monitoring of technical rooms
  • Monitoring of boiler room systems
  • Monitoring of industrial machines
  • Greenhouse, food storage and pharmaceutical storage monitoring
  • Remote monitoring of infrastructure
💡

Practical example: In a boiler room, temperature sensors are connected via the RJ11 ports, a Modbus/RTU electricity meter via RS-485 and a gas meter via the M-Bus Master to the Perseus Energy 242. In addition, the device reads the battery status of an SNMP-capable UPS via the Meters API. An alarm is triggered as soon as two out of three sensors exceed a threshold, and the notification is sent by e-mail or via the SensDesk portal.

Frequently asked questions

What is the HW group Perseus Energy 242 and what is it used for?

The Perseus Energy 242 is a LAN solution in a metal housing with M-Bus Master for energy monitoring and control applications. It combines external sensors, detectors and meters with data from other LAN devices and is particularly suitable for boiler rooms, industrial plants, pharmaceutical storage and general infrastructure monitoring.

What is the difference between the base unit and the "set"?

The base unit "Perseus Energy 242" requires an external 24 V power supply; a power supply unit is not included. The "Perseus Energy 242 set" variant additionally includes a 24V EU power adapter with 2-pin plug. The desired option must be selected in the shopping cart.

What is the M-Bus Master and what is it needed for?

The M-Bus Master is a dedicated terminal block on the Perseus Energy 242 that allows M-Bus-compatible meters such as electricity, gas or water meters to be connected and read directly – in addition to the RS-485 interface for Modbus/RTU devices.

What exactly is the Meters API?

The Meters API is a special feature of the Perseus product range: in addition to the sensors connected directly, the device can also read values from other devices on the same LAN, for example from other HWg devices, SNMP-capable UPS systems or network PDUs, and include this data in its own analyses and alarms.

How many sensors and meters can be connected?

Directly available are 4x RJ11 ports with up to two 1-Wire UNI sensors each, one RS-485 connection for Modbus/RTU and one M-Bus Master connection. In total, the Perseus Energy 242 supports up to 100 meters or 1,000 variables according to the manufacturer, among other things through the additional integration of devices via the Meters API.

How is the Perseus Energy 242 powered?

The device requires exclusively a 24 V DC voltage via a terminal block, which also provides a 24V output for external devices. A matching 24V EU power adapter with 2-pin plug is only included with the "set"; with the base unit it must be obtained separately.

What is the maximum length of the water leak sensor cable?

An external water sensor cable with a total length of up to 185 metres can be connected to the WLD zone connection.

What security features does the device offer?

The Perseus Energy 242 supports Radius authentication according to IEEE 802.1X, HTTPS with customer certificate, separate admin and user accounts as well as IPv6 and SNMP v1/v3 including SNMP traps.

Questions about the Perseus Energy 242?

Our support team in Germany will advise you free of charge on selection, sensors and configuration.

Datasheets
Datasheet 1

Oops! Your browser doesn't support PDFs!

Datasheet 1 (538.05 KB)
Datasheet 2

Oops! Your browser doesn't support PDFs!

Datasheet 2 (10.56 MB)
Available Variants (Please select above)
  • Perseus Energy 242:
    Requires external 24V power supply - power adapter NOT included.
  • Perseus Energy 242 set:
    Includes 24V EU power adapter with 2-pin plug.

Interfaces:

  • 4× RJ11 ports – 1-Wire / 1-Wire UNI sensors
  • 1× M-Bus master (terminal block)
  • 1× RS-485 (Modbus/RTU) terminal block with 12V
  • 1× WLD zone for external water leak detection cable
  • 1× DO (relay output)
  • 2× DI (digital inputs, dry contact)
  • Ethernet RJ45 (100BASE-T)

Technical Specifications:

  • Power supply: 24 V
  • Operating temperature: -30°C to 85°C (-22°F to 185°F)
  • Enclosure: Metal housing, DIN rail
  • Dimensions: 35 × 111 × 140 mm
  • Warranty: 24 months

Communication:

  • Open API: SNMP, XML, Modbus/TCP, MQTT
  • Alerts: SNMP Trap, Email
  • Meters API: HWg XML, Modbus/TCP, MQTT, SNMP
  • Supports up to 100 external meters and sensors
  • Up to 1000 values (variables) manageable

Security:

  • IPv6 support
  • SNMP Traps, SNMPv3
  • Radius – IEEE 802.1X
  • Admin and user accounts
  • HTTPS with client certificate

Functions:

  • Local calendar-based scheduler
  • Multiple conditions and actions per variable
  • Local Lua scripts
  • Unit conversion
  • Template repository for third-party sensors
  • Central security management 802.1X

Manufacturer information:

HW group s. r. o.

Rumunská 26

Prague, 120 00
Czech Republic

Phone: +420 222 511 918

Email: sales@hwg.cz

Responsible person:

Didactum® Security GmbH

Im Mühlenfeld 4

48163 Münster
Deutschland

Fon: (+49) 250 19 71 63 54 / (+49) 171 33 11 577

Email: info@didactum-security.de

Questions?

You have questions about HW group products?

You would like a quote?

Contact us