using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Text;
using System.Windows.Forms;
//Add the following references manually to the header
using NationalInstruments.DAQmx; //Don't forget to add the references to the NI libraries in the project explorer as well
using System.IO;
 
namespace DAQMX
{
    public partial class Form1 : Form
    {
        //Global variables
        private Task OutTask;    //kimeneti Task: Dev1/ao0
        private AnalogSingleChannelWriter writer;  
        private Task InTask;    //bemeneti Task: Dev1/ai0
        private AnalogSingleChannelReader reader;
 
        double Minimumvoltage = 0;
        double Maximumvoltage = 5;
        public Form1()
        {
            InitializeComponent();
        }
 
        private void Form1_Load(object sender, EventArgs e)
        {
            //Read button is disabled when the program loads
            readButton.Enabled=false;
        }
 
	//The measurement has to be initialized first
	//For example by using a button press
        private void startButton_Click(object sender, System.EventArgs e)
        {
			//Output
			OutTask = new Task();  //Task constructor
			//Creating the output channel
			OutTask.AOChannels.CreateVoltageChannel("Dev1/ao0", "",
                    Minimumvoltage, Maximumvoltage,
                    AOVoltageUnits.Volts);		
			writer = new AnalogSingleChannelWriter(OutTask.Stream);
			//Input
			InTask = new Task();  //Task constructor
			//Creating the input channel
			InTask.AIChannels.CreateVoltageChannel("Dev1/ai0", "",
                    AITerminalConfiguration.Differential, Minimumvoltage, Maximumvoltage,
                    AIVoltageUnits.Volts);		
			reader = new AnalogSingleChannelReader(InTask.Stream);
                        //The read button is enabled after the initialization
                        readButton.Enabled=true;
	}
        private void readButton_Click(object sender, System.EventArgs e)
        {
                        Double input = 0;
                        //The below function performs the writing and reading of the voltage values
                        input=write_And_Read();
                        //displaying the result
                        inputBox.Text=input.ToString("0.000");
        }
        //writing voltage (value stored in data variable)
        //and reading voltage on the input
	private Double write_And_Read()
	{
			Double data=0.2;   //always between 0 and 5 V!
			writer.WriteSingleSample(true,data);
                        //the function returns the measured voltage
			return reader.ReadSingleSample();
	}
        private void Form1_FormClosed(object sender, FormClosedEventArgs e)
        {
            //free up resources 
	    OutTask.Dispose();
	    InTask.Dispose();
        }
 
     }
}