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:

Fix Defined Firewall

Network one-way street

The Fix Defined Firewall links computers to networks with no feedback, so that the computers are able to receive only. All received network packets are passed on in one direction to the reading host. Data traffic to the safe network is not possible - neither from the reading computer nor from the firewall itself.



  • 2x Ethernet 100BaseT
    • Autosensing/Auto-MDIX

Power supply:

  • External power
    • Screw terminals, 24V-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


Feedback-free network connection

The Fix Defined Firewall is a fixed configured firewall for unidirectional data flow. Data packets arriving at the input are passed transparently to the output, with the opposite direction completely blocked. This pre-configuration cannot be changed. The Fix Defined Firewall has no configuration interface, none of its own network services, and no Ethernet address. For applications for example in telemetry or data flow analysis this ensures feedback-free connection of receiving computers to a network with high security requirements.

Due to its clearly defined scope of function the firmware for the Fix Defined Firewall needs no traditional operating system and is free of open source and third-party components.

Startup is true plug and play, and in PoE environments requires only connection of the network cables. Without PoE, the supply voltage is additionally required - that’s it.

Technical data

Connections and displays:

  • Network:
    • 2x 100BaseT Autosensing/Auto-MDIX
    • RJ45
  • Galvanic isolation:
    • Network connections min. 1500 V
  • Supply voltage:
    • Power-over-Ethernet (PoE) or
    • DC 24V .. 48V (+/-10%) and
    • AC 18Veff .. 30Veff (+/-10%)
  • Supply connection:
    • Plug-in screw terminal, 5.08mm spacing
    • Labeled "L+" and "M"
  • Current consumption:
    • PoE Class 1 (0.44W - 3.84W)
    • or for external supply:
    • typ. 80mA @24V DC
    • max. 95mA @24VDC
  • Indicators:
    • 2x LEDs for network status
    • 1x LED system
    • 1x LED power

Housing and other data:

  • Housing:
    • Plastic compact housing for top-hat rail mount
    • 105x22x75mm (LxWxH)
  • Enclosure rating:
    • IP20
  • Weight:
    • approx. 120g
  • Ambient temperature:
    • Storage: -40..+85°C
    • Operating 0..+60°C (non-contiguous mounting)
  • Permissible relative humidity:
    • 5..95% RH, non-condensing
  • Scope of delivery:
    • 1x Fix Defined Firewall
    • 1x Quick Guide


*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€

* 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.