How to measure a counter using Modbus

I am trying to ping Socomec using the Modbus protocol, having researched, I found NModbus, the C # library. I have never used libraries or C # before (usually Java), but I have to dive directly.

I installed Visual Studio Express for C # and installed .Net. I copied the contents of the NModbus file to the project folder and added links to the two main DLLs. It did not work with .Net 4, but I redirected to 3.5 (and removed the Microsoft.Csharp link), and everything seemed to compile.

I use this example to try to connect to a slave. When I ran this and set the startAdress variable to the right one (in Socomec documentation), all I get is an empty console window.

In short, am I using the correct method / parameters, incorrect configuration / code? How to connect to this counter?

My code is:

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.IO.Ports;
using Modbus.Data;
using Modbus.Device;
using Modbus.Utility;


namespace NModbus
{
    class SerialMaster
    {
        static void Main(string[] args)
        {
            ModbusSerialAsciiMasterReadRegisters();
        }

        public static void ModbusSerialAsciiMasterReadRegisters()
        {
            using (SerialPort port = new SerialPort("COM1"))
            {
                // configure serial port
                port.BaudRate = 9600;
                port.DataBits = 8;
                port.Parity = Parity.None;
                port.StopBits = StopBits.One;
                port.Open();

                // create modbus master
                IModbusSerialMaster master = ModbusSerialMaster.CreateAscii(port);

                byte slaveId = 1;
                ushort startAddress = 50536;
                ushort numRegisters = 5;

                // read five registers       
                ushort[] registers = master.ReadHoldingRegisters(slaveId, startAddress, numRegisters);

                for (int i = 0; i < numRegisters; i++)
                    Console.WriteLine("Register {0}={1}", startAddress + i, registers[i]);
                    Console.ReadLine();
            }

            // output:
            // Register 1=0
            // Register 2=0
            // Register 3=0
            // Register 4=0
            // Register 5=0
        }
    }
}