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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).

    Wiring #57737

  • In the connection example shown inputs, outputs and the Web-IO itself are powered from the same source. Alternatively 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).

    Wiring #57737

  • 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 #57730/57731

Wiring #57730/1

  • In the example shown the device power and power for the outputs are from a 24V source. Alternatively 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. Alternatively 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, 8xRelay Out, Model #57738

Wiring #57738

  • The inputs on the Web-IO #57738 are technically similar to those on the #57730, except that the switching threshold is between 3V and 4V. The Web-IO provides auxiliary power outputs for controlling the inputs through potential-free contacts.

    The outputs use potential-free contacts: 7x changeover and 1x normally open.


Web-IO Digital 4.0 4xIn/Out, Model #57733

Wiring #57733

  • The four IO-channel inputs on the Web-IO #57733 can be used as inputs or outputs. Used as an input the Web-IO detects signals above 9V DC as ON. As outputs the applied supply voltage is switched externally.


Web-IO Digital 4.0 4xIn/Out, Model #57736

Wiring #57736

  • The 16 IO channels/inputs of the Web-IO #57736 can be operated as inputs or outputs. Used as an input the Web-IO recognizes signals over 9V DC as ON. In Output mode the applied supply voltage is switched out.


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

Wiring #57734

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

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