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:

Web-IO 4.0 230V Relay 4xNO, 4xCO

Switch remotely...

Using the Web-IO 4.0 230V Relay 4xNO, 4xCO you can control 230V switching signals via TCP/IP Ethernet. There are numerous Web and network services available for switching up to 6A with the eight integrated relays - even directly from the browser or from a smart phone. Using protocols such as OPC UA, MQTT and REST the Web-IO is an ideal fit in the world of Industry 4.0 and the Internet of Things.


Switching signals:

  • 8 switching outputs:
    • via bistable relays
    • 4 x potential-free normally open contacts for 230V mains
    • 4 x potential-free changeover contacts for 230V mains
    • Switching currents up to max. 6A


  • Intuitive Web interface for simpler operation
    • Select between German or English
    • Switching the outputs directly from the Web interface
    • Adaptation for smartphone
    • HTTP and HTTPS
  • Current Industry 4.0 protocols:
    • OPC UA, REST and MQTT support
    • AMQP on request
  • Box-to-Box
    • Pass switching signals over the network 1:1
  • Alarm and reporting functions:
    • Email for alarm sending or as status report
    • SNMP polling / alarm traps V1 V2 V3
    • Switching your outputs in alarm situations
    • Switching the outputs on another Web-IO
    • HTTP requests for controlling third-party devices
    • Up to 30 actions can be configured
  • Dynamic integration into other Web sites:
    • Direct access to the contacts via HTTP requests, AJAX and JavaScript
  • Additional software interfaces for incorporating into your systems/databases:
    • OPC UA, OPC DA
    • Modbus TCP
    • Syslog, SNMP V1 V2 V3
    • TCP and UDP sockets, client and server
    • FTP (data logging)
  • Internal clock
    • Time synchronization via time server calibration
    • Battery-backed device clock
  • Possible applications:
    • Cross-location switching
    • House and building automation
    • Light, gate and cabinet control
    • More uses can be found here.

Power supply:

  • External power
    • Screw terminal
    • 230V AC (50Hz)

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

Technical data

Connections, displays and control elements:

Digital switching outputs:   via bistable relays
4 x potential-free normally open contacts, max. 6A
4 x potential-free changeover contacts, max. 6A
Network:   10/100BaseT autosensing
Power supply:   230V AC (approx. 15mA@230V)
Galvanic isolation:   Digital output to network: min. 1000 V
Adapters:   1 x 3x screw terminals for power
2 x 11x screw terminals for the outputs
1 x RJ45 for network
Indicators:   Status LEDs for network
  2 LEDs for switching states

Data transmission:

Protocols:   HTTP and HTTPS
  TCP and UDP sockets, client and server
  MQTT - Publish and Subscribe
  SNMP V1 V2 V3 including traps
SMTP e-mail sending
  OPC server
  Modbus TCP
  Inventory keeping, group management
Response times:   Data and switching traffic: typically 12 ms

Housing and other data:

Housing:   Plastic housing for top hat rail installation
  90x116x56 mm (LxWxH)
Enclosure rating:   IP20
Weight:   approx. 330 g
Storage temperature:   -25°C - 70°C
Operating temperature:   0°C - 40°C
Permissible relative humidity:   5..95% RH (non-condensing)
Scope of delivery:  

1 x Web-IO 4.0 230V Relay 4xNO, 4xCO
1 x Quick Guide
Power supply and other accessories can be
ordered separately


*Net unit price for
commercial users
  • Mechanical Accessories

    • 19" DIN rail
    • 58813
    • 21.00€
    • Wall mount housing, enclosure rating IP66 / IP67
    • 11120
    • 54.00€
  • Supplementary network products

    • Ethernet Switch Gigabit Industry, 4 Ports
    • 55614
    • 148.00€
    • Ethernet Switch Industry, 4 Ports
    • 55604
    • 218.00€

* 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.