Dedicated modem designed to support the AS series of meters from Honeywell (Elster)

DM686 is a GSM-based remote data communication terminal designed to work with the AS series of meters from Honeywell (Elster). The modem is fitted inside a meter’s original terminal strip housing to ensure an appropriate IP protection rating.


  • Dimensions: the modem is fitted inside the original terminal strip housing of an AS series meter
  • IP protection rating: same as the meter’s IP rating following installation
  • Power supply voltage: 100 to 240 V AC
  • Operating temperatures: -25 to +60°C
  • Sealing: communications connectors, power cords, SIM card slot and antenna connector
  • Clear status and signal level indications with LEDs on the front panel

Radio communications

  • 900/1800 MHz for CSD on 2G networks
  • 900/1800 MHz for GPRS/EDGE on 2G/2.5G networks
  • 900/2100 MHz for UMTS/HSPA on 3G networks


  • Support of TCP/IP, UDP/IP, ICMP, Telnet
  • Transparent handling of data from the serial interface
  • Powerful feature set to support electricity meters (including time synchronization and automatic protocol recognition)
  • Real-time clock with battery backup; clock synchronization via NTP or from the GSM
  • Remote and local hardware and software restart feature
  • Proprietary algorithms to monitor key quality metrics of the entire communication channel in TCP/IP mode and GSM mode: Link Control and GPRS Control
  • Device configuration access security controls
  • Internal event log
  • Built-in IP address filter to support whitelisting and blacklisting for inbound connections
  • Compliance with industry standards in terms of technical and security specifications


  • RS485 serial interface (terminal block)
  • mini USB 2.0 configuration port
  • SMA antenna port
  • SIM card slot (2FF USIM)