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

Application for the Web-IO Digital:

Web-IO Digital - Supply voltage and input/output circuit


Here we show an example of how the wiring for various Web-IO models could look:


Please note: Before you begin actually wiring in the field, please read the manual and in particular the safety instructions contained there. Wiring must be performed only by trained personnel.


Web-IO Digital 4.0 2xIn, 2xOut, Model #57737

  • The Web-IO #57737 can be powered as desired from the two-pole terminal with 12V - 48V or the RJ45 connector via PoE (Power over Ethernet).

    Digital 2x wiring

  • In the connection example shown inputs, outputs and the Web-IO itself are powered from the same source. Alternately the inputs and outputs can be powered with 30V if the Web-IO is powered separately through the two-pole terminal.

  • If the Web-IO itself is powered by PoE, it can use the + and - terminals on the six-pin front terminal to output an auxiliary voltage of 24V which can be used for supplying the IO (max. 125 mA).

    Digital 2x wiring

  • This requires that the web interface be used by going to menu Basic settings >> Inputs/Outputs and enable Internal 24V IO supply.


Web-IO Digital 4.0 12xIn, 12xOut, Model #57730

Digital signal wiring diagram

  • In the example shown the device power and power for the outputs are from a 24V source. Alternately the outputs can be supplied separately with between 6V and 30V on terminals 15 and 16.

  • The inputs are current sinking and arranged in galvanically isolated groups with one dedicated ground potential (GND) each. In the example shown the GNDs are connected together. Alternately to the circuit shown you may also use signals (-30V to +30V) from three different ground potentials. The switching threshold is +9V.


Web-IO Digital 4.0 12xIn, 6xRelay Out, Type #57734

Relay wiring

  • The inputs of the Web-IO #57734 are technically identical to those of the #57730. The outputs however use potential-free contacts.