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AN27: I/O Controller - connecting relay to 230V AC

Czech version

English version

I/O Controller can read states of digital inputs and control 8 outputs over network. Inputs and outputs are designed for low voltage up to 50V. This application note describes how to connect relay to I/O Controller. You can control 230V AC (110) device over external relay or detect voltage over switching contact of 230V AC relay.

I/O Controller product offers:

8 inputs for voltage 5 to 20V DC
8 transistor outputs for voltage circa 12V / 300mA (max. 50V)
serial port RS-232/485

This application note describes:

Measuring of voltage 110/230V (2x 230V relays)
Two 230V relays, contacts are connected to I/O Controller inputs.
Control of 110/230V voltage (2x 12V relays)
Two 12V relays, controlled I/O Controller outputs, relay contacts control voltage area 110/230V
Applications of SW solution
Overview of application that can be used for control

Note: I/O Controller inputs can be controlled from any contact, for example from button or switch that uses 12V power supply I/O Controller. Here are used Relay contacts for clearness.

Connecting scheme

Details of inputs and outputs connecting to I/O Controller:

I/O Controller manual
- I/O Controller pin description (see page 7)
- Example how to connect light bulb and switch to I/O Controller (see page 7)
Power for the output relays from external 24V DC power source

Inputs

We connect 2 relay contacts to inputs I.0 and I.4. We use I/O Controller as a power source (typical 12V).

Connect collective ground of inputs (I.GND) to device ground (GND) - marked (a) in scheme.
Connect I/O Controller input (for instance I.0) to relay contact (see relay number terminal 14)
I.0 input connect to power supply (PWR) (see terminal 21)
Connect contact of the second relay to I.4 - see scheme

Outputs

Connect inductor of 2 relays relay to outputs O.2 and O.4. We use I/O Controller as a power source (typical 12V) to control relay.

Connect output of surge guard (O.COM) to device power supply (PWR) (marked as b in scheme)
This connection protects I/O Controller from spike of relay inductor.
Connect I/O Controller output (O.2) to relay inductor (relay terminal A2)
Connect the second relay inductor (see A1) to power supply of I/O Controller (PWR)
Connect the second relay controlled from output O.4 same way - see scheme.

If you need control output relays to other voltage than I/O Controller device power is (up to 48V DC), check the scheme: Power for the output relays from external 24V DC power source.

SDK library control

SDK (Software Development Kit) is available for free upon request to simplify control of I/O Controller. This library will save your time and money for developing own applications for I/O Controller.

SDK consists functions as:

Network search for I/O Controller (UDP Search)
Device IP address setting (UDP Config)
I/O pins control (read bit/byte, set bit/byte)
Remote setting of serial port parameters (speed, parity, etc.)
Receive information of I/O Controller input state change without established TCP connection (I/O Controller is TCP client)

The library contains transparent manual describing interface. Examples in different program (MS Visual Basic, Delphi, Borland C++, C# etc.) languages are available for free to illustrate applications of SDK library.

>> HWg SDK (Software Development Kit)

Control of relay over HW Virtual Serial Port

Ethernet I/O Controller - binary inputs, binary outputs, 2 relays on input, 2 relays on output, Virtual Serial Port

Connect I/O Controller to Ethernet and power supply.
Install HW Virtual Serial Port (download from HW Virtual Serial Port)
Click “HW_VSP.exe“ to run application
Click on Find Modules button on UDP Search tab and select MAC address of your device from list
Switch to Binary I/O tab where all I/O Controller inputs and outputs are displayed
Click Read Values to reload values of outputs and inputs.
Set switches to desired values and click Set Values. By doing this you change of device outputs You can hear a click in case you change output that relay is connected to.

Different program languages examples to control relay

You can use basic program language application to control relay connected to I/O Controller. Sample examples for program languages are available on I/O Controller page for free.

Relay control over C++
Simple communication examples with common TCP/IP device in Borland C++ Builder 6.00. The example demonstrates simple terminal client and basic NVT commands (Network Virtual Terminal).
Relay control over Delphi
Simple communication example with common TCP/IP device in Borland Delphi 5 demonstrates simple client terminal including basic NVT commands (Network Virtual Terminal) and extention for I/O functions.
Relay control over MS Visual Basic
Very simple routines for using NVT commands and TCP/IP device through Winsock in MS Visual Basic 5.0. Very simple commands for remote control of I/O Pins are implemented, TEA not.
Relay control over Java
Very simple method to control remote I/O pins via JAVA application. The application can be modify according to your wish
Relay control over PHP
Very simple method to control remote I/O pins of I/O Controller. User loads a WWW page from PHP server which takes following actions before response: opens connection to IP address and port, reads values, closes connection to binary device and displays loaded values to the user on the WW page.