Visual Studio C# USB 4 Relay board controller

Question

What I want to do is to create a simple Windows form app to control a Relay board to power on and off some lights. Nothing serious it is a personal project. This the link to the relay board I have : http://www.canakit.com/catalog/product/view/id/627/s/4-port-usb-relay-controller/ .

Now my question is how can I send commands to the relay and receive some from it via USB. The relay board comes with a driver. The boards support the commands below. So how do I send them to the board via my windows form.

From the user manual: It is compatible with both Windows and Apple OS X, as well as various Linux flavors and appears as a USB CDC (Communications Device Class) device which creates a Virtual Serial (COM) port allowing easy communication with the board through any programming language that supports serial communications (VB, VB.NET, C#, C, C++, Perl, Java, etc). A complete set of easy to use commands are available for complete control of all relays, I/O channels and sensors.

Supported Commands:

RELx.ON
RELx.OFF
RELx.TOGGLE
RELx.GET

RELS.ON
RELS.OFF
RELS.GET

CHx.ON
CHx.OFF
CHx.TOGGLE
CHx.GET
CHx.SETMODE
CHx.GETANALOG
CHx.GETTEMP

CHS.ON
CHS.OFF
CHS.GET
CHS.SETTEMPRES

Zeeshan Zeeshan · Accepted Answer · 2017-01-24T08:09:43

Plugin the device once you have installed the driver. Open device manager where you should now see a COM port as given by board manufacturer. You could have the COM port, baud rate, parity etc. provided in the documentation. Now you can create a c# console application with following code, I have made a sample to issue a RELx.ON followed by a RELx.OFF after a 3 second gap:

using System;
using System.IO.Ports;

namespace RelayConsole
{
    class Program
    {
        public static SerialPort port = new SerialPort("COM5", 9600, Parity.None, 8, StopBits.One);
/* Replace COM5 with your COM port, 9600 with baud rate of your board, parity and bits as well as per your device documentation */

        static void Main(string[] args)
        {
            SerialProgram();
        }

        static void SerialProgram()
        {
            try
            {
                port.Open();
                port.Write("RELx.ON"); /* You can pass any command as per your documentation in port.Write */
                System.Threading.Thread.Sleep(3000);
                port.Write("RELx.OFF");
                Environment.Exit(0);
            }
            catch (Exception ex)
            {
                if(ex is System.IO.IOException)
                {
                    Console.WriteLine("Port Exception: " + ex.ToString());
                    Console.ReadLine();
                }
                else
                {
                    Console.WriteLine("General Exception: " + ex.ToString());
                    Console.ReadLine();
                }
            }
        }
    }
}

Visual Studio C# USB 4 Relay board controller

3 Answers