ReadStruct returns no values for 4-Bool structure, direct Read works correctly

[GimmyZ98]

I'm testing a program and trying to read a structure of 4 bools, and although I'm connected to the PLC and no errors are being thrown, the values of the tags are not actually being read. I tried adding a Read right after the ReadStruct, using the same tag, and with this second method I was able to read the tag’s value correctly. I can't "see" any errors within my program. I'm also sharing the code and two screenshots: one showing the contents of the DB in the PLC and one showing the form with the printout of the read values.

`

using S7.Net;
using System;
using System.Threading.Tasks;
using System.Windows.Forms;

namespace WinFormsApp1
{
    public partial class Form1 : Form
    {
        static Plc plc = new Plc(CpuType.S71500, "192.168.100.170", 0, 1);

        public struct Test
        {
            public bool a { get; set; }
            public bool b { get; set; }
            public bool c { get; set; }
            public bool d { get; set; }
        }

        public Form1()
        {
            InitializeComponent();
            this.Load += Form1_Load;
            this.FormClosed += Form1_FormClosed;
        }

        private async void Form1_Load(object sender, EventArgs e)
        {
            try
            {
                plc.Open();

                if (!plc.IsConnected)
                {
                    MessageBox.Show("Connessione al PLC fallita.");
                    return;
                }

                await StartReadingLoop();
            }
            catch (Exception ex)
            {
                MessageBox.Show("Errore: " + ex.Message);
            }
        }

        private async Task StartReadingLoop()
        {
            while (plc.IsConnected)
            {
                try
                {
                    Test testData = new Test();

                    testData = (Test)plc.ReadStruct(typeof(Test), 193, 0);

                    _A1_Test.Text = $"A: {testData.a}";
                    _A2_Test.Text = $"A: {plc.Read("DB193.DBX0.0").ToString()}";                    
                }
                catch (Exception ex)
                {
                    MissioneAbortita.Text = ex.Message;
                    Console.WriteLine(ex.Message);
                }

                await Task.Delay(100);
            }
        }

        private void Form1_FormClosed(object sender, FormClosedEventArgs e)
        {
            if (plc != null && plc.IsConnected)
            {
                plc.Close();
            }
        }
    }
}

`

[stefanak-michal]

Hi. Add 4 more bools to your struct even when they don't exists in PLC, so in counting they will add up to one byte.