W&T connects
Interfaces for TCP/IP, Ethernet, RS-232, RS-485, USB, 20mA, glass and plastic fiber optic cable, http, SNMP, OPC, Modbus TCP, I/O digital, I/O analog, ISA, PCI
Data sheet:


1:1 replacement for analog/ISDN modems in the TCP/IP network

The AT-Modem Emulator is a 1:1 replacement for traditional analog and ISDN modems such as used in climate control technology, alarm systems or measuring technology. Instead of the telephone network the AT-Modem-Emulator uses the TCP/IP/Ethernet for the connection.



  • 1 x RS232
    • Pin- and AT command-compatible with standard modems
  • 1 x Ethernet 10/100BaseT
    • Autosensing/Auto-MDIX

Management and Connectivity:

  • Remote configuration
    • Startup using WuTility (three clicks and you’re done), DHCP, serial
    • Web-Based-Management
    • Telnet
  • Transparent communication
    • Windows COM Port Redirector and virtual modem ports
    • Box-to-Box
  • Optional TLS encryption
    • For virtual modem ports and box-to-box mode

Power supply:

  • External
    • Screw terminals, 12V-48V DC
  • Power-over-Ethernet (PoE)
    • Phantom power using data pairs
    • Power over unused wire pairs

Standards & more

  • Conforms to standards both in office and industrial environments:
    • High noise resistance per EN 61000-6-2
    • Low noise emission per EN 55032:2015 + A1 Cl. B, EN 61000-3-2 & EN 61000-3-3
  • 5 year guarantee

Run modes

Abandoning the analog/ISDN network

By no later than 2018 the traditional analog and ISDN telephone network will be abandoned and the changeover of all telephone connections to IP-based technology will be complete. Applications with remote monitoring and/or remote alarming whose communication takes place via modem over the traditional telephone network must be converted by this time. The AT-Modem-Emulator accomplishes this conversion by means of a simple component replacement without major changes to the proved hardware/software combination.


The AT-Modem-Emulator is a 1:1 replacement for traditional analog or ISDN modems for example in air conditioning, alarm sending or measuring technology. Instead of the telephone network the AT-Modem-Emulator uses the TCP/IP/Ethernet for the connection. Configuration of the serial devices as well as cable connections remain unaffected by the changeover. Only the previously used call number is replaced by the IP address or URL of the desired remote side.
To application example ...

Virtual modem ports

The COM Port Redirector for all current Windows versions >=XP allows the creation of virtual COM ports which provide a virtual AT-Modem-Emulator. Both outgoing and incoming connections are supported. From the standpoint of a central software application this eliminates use of an external AT-Modem-Emulator. Especially in virtual environments, e.g. under VMWare, this eliminates the often vulnerable passing of host-side COM ports to the guest system.
Data sheet with download link

Technical data

Connections and displays:

  • Serial port:
    • 1x RS232 port, DCE
    • DB9 receptacle
    • 1200 to 115.200 kBaud
    • 7,8 data bits
    • 1,2 stop bits
    • Parity No, Even, Odd
    • Flow control No, RTS/CTS, Xon/Xoff
  • Serial modes:
    • RS232
  • Network:
  • Galvanic isolation:
    • Network connection min. 1500 V
  • Power supply:
    • Power-over-Ethernet (PoE) or
    • DC 12V .. 48V (+/-10%) or AC 18Veff .. 30Veff (+/-10%)
  • Supply connection:
    • Plug-in screw terminal, 5.08mm spacing
    • Labeled "L+" and "M"
  • Current consumption:
    • PoE Class 1 (0.44 - 3.84W)
    • or for external supply:
    • typ. 55mA @24V DC
    • max. 70mA @24VDC
  • Displays:
    • 1 LED Power
    • 1 LED Status
    • 1 LED Error
    • 2 LEDs network status

Housing and other data:

  • Housing:
    • Plastic compact housing for top-hat rail mount
    • 105x22x75mm (LxWxH)
  • Enclosure rating:
    • IP20
  • Weight:
    • approx. 105g
  • Ambient temperature:
    • Storage: -40..+70°C
    • Operating: 0..+60°C (70°C on request)
  • Permissible relative humidity:
    • 5..95% RH, non-condensing
  • MTBF:
    • 637,767 h @25°C per MIL-HDBK-217
  • Life expectancy:
    • > 25 years at 25°C ambient temperature
  • Scope of delivery:
    • 1x AT-Modem-Emulator
    • 1x Quick Guide
    • Quick Guide in German/English


*Net unit price for
commercial users
  • Power supplies

    • Plug-in power supply, 24V / 500mA DC with Euro plug
    • 11021
    • 21.00€
    • Plug-in Power Supply, 24V / 750mA DC with Euro, US and UK plug
    • 11026
    • 38.00€
    • Power supply for DIN rail, 24V / 630mA DC
      (merchandise, 2-year manufacturer’s guarantee)
    • 11080
    • 33.00€
  • Mechanical Accessories

    • Mounting bracket for wall mounting
    • 58812
    • 11.20€
    • 19" DIN rail
    • 58813
    • 21.00€
    • Wall mount housing, enclosure rating IP66 / IP67
    • 11120
    • 54.00€
  • Software

    • Windows COM Port Redirector Legacy
    • 00102
    • free
    • Download

* Our offering is intended only for commercial users. We will be happy to refer private end customers to trading partners through whom our products can be purchased.