Application notes overview - All Application notes

The HW group product portfolio includes three major domains: Environmental, system and process monitoring devices; technology for IP based serial interface system control and data logging and Access Systems.


  • Application note 42: 0-20mA or 4-20mA current loop

    When using LAN and GSM sensors by HW group, it is important to understand the difference between a 0..20mA current loop and a 4..20mA current loop. This Application Note explains the difference.
  • Examples of using Poseidon Industrial Bus

    The application example details the use of the Industrial Bus (RS-485) for connecting sensors to a Poseidon2 4002 unit. It describes in detail the wiring of cables and connectors, as well as the DIP switch settings for supplied accessories.
  • How to connect HWg WLD to a HWg-SMS-GW3 gateway

    How to connect HWg WLD to a HWg-SMS-GW3 gateway
  • How to send SMS via HWg-SMS-GW3

    HWg-SMS-GW3 is primarily intended for use with HW group products and software. However, its communication interfaces are sufficiently documented for use with third-party systems. This Application Note shows how to use HWg-SMS-GW3 in such third-party.
  • Modbus/TCP in Poseidon2 and Damocles2 family

    The Modbus protocol itself allows to share the memory area for variables, e.g. the readings, over one of the physical interfaces. Modbus/TCP is an extension of this protocol for communication over Ethernet.
  • MQTT in practice on Poseidon2/Damocles2

    MQTT is a lightweight TCP/IP protocol designed for use in IoT applications or in situations where many external devices send data to a central hub. The central hub can aggregate data and further distribute them to all subscribed devices.
  • netGSM - How it work with HW group devices

    The netGSMfunction is designed for sharing one GSM modem connected to one unit with other devices on the same network. This means that more Poseidon units can send Alarm SMS using one GSM modem thus reducing network topology and costs.
  • Poseidon – hysteresis - Preventing false alarms

    Poseidon monitoring unit sends SMS, e-mail, and SNMP traps whenever a sensor value is outside of a safe range. However, when the temperature or humidity fluctuates, the unit can send tens or hundreds of messages that are unnecessary and bother the user. A
  • Remote energy monitoring with ABB DELTAMax M-Bus meters

    Case study showing how to connect ABB M-Bus power meters to the Ethernet. Tested with DHM13007 and DBM23000 three phase ABB M-Bus meters. The ABB ODIN meters family (1 or 3 phase) is also supported with the OA1408 serial to M-Bus converter.
  • Selecting M-BUS communication type (displaying multiple values from a meter)

    Activation of an extended M-Bus communication mode using a hidden option.
  • Sensor accuracy over time

    All sensors – temperature, humidity, voltage and others are getting old through time and their parameters are changed. This document describes dangerous environments for temperature and especially humidity sensors.
  • Virtual outputs in Poseidon2/Damocles2

    Virtual outputs in Poseidon2 and Damocles2 units allows to use outputs from different Poseidon2 and Damocles2 units (Box2Box).


  • HTTPS in Poseidon2 and Damocles2

    Zařízení Poseidon2 a Damocles2 podporují od verze FW verze 2.0.15 komunikaci HTTPS (WEB) i pomocí XML. Tento dokument vysvětluje, jak používat HTTPS a jak generovat (včetně generování samotným Poseidonem), nainstalovat a spravovat certifikáty.
  • The SNMP v3 is now supported in all the Poseidon2 units

    The SNMP v3 is now supported in all the Poseidon2 units. This is a major update that brings many advantages and improvements. The following text will explain all the advantages of the SNMP v3 and how to use it in the Poseidon2 devices.


IP Serial