#region Using
using System;
using Microsoft.VisualStudio.TestTools.UnitTesting;
using S7.Net;
using S7.Net.UnitTest.Helpers;
using S7.Net.UnitTest;
using System.ServiceProcess;
#endregion
/**
* About the tests:
* ---------------------------------------------------------------------------
* The tests were written to show how to use this library to read and write
* different types of values, how to box and unbox values and of course to
* address some of the bugs of the library.
* These tests are not meant to cover 100% the code, but to check that once a
* variable is written, it stores the correct value.
* ----------------------------------------------------------------------------
* The plc used for the tests is the S7 "server" provided by Snap7 opensource
* library, that you can get for free here:http://snap7.sourceforge.net/
* The implementation of the server will not be discussed here, but there are
* some issues with the interop that cause the server, and unit test, to fail
* under some circumstances, like "click on Run all tests" too much.
* This doesn't mean that S7.Net has bugs, but that the implementation of the
* server has problems.
*
*/
namespace S7.Net.UnitTest
{
[TestClass]
public class S7NetTests
{
#region Constants
const int DB2 = 2;
#endregion
#region Private fields
Plc plc;
#endregion
#region Constructor
///
/// Create a plc that will connect to localhost (Snap 7 server) and connect to it
///
public S7NetTests()
{
plc = new Plc(CpuType.S7300, "127.0.0.1", 0, 2);
//ConsoleManager.Show();
ShutDownServiceS7oiehsx64();
S7TestServer.Start();
plc.Open();
}
#endregion
#region Tests
[TestMethod]
public void T00_TestConnection()
{
if (plc.IsConnected == false)
{
var error = plc.Open();
Assert.AreEqual(ErrorCode.NoError, error, "If you have s7 installed you must close s7oiehsx64 service.");
}
}
///
/// Read/Write a single Int16 or UInt16 with a single request.
/// Test that writing a UInt16 (ushort) and reading it gives the correct value.
/// Test also that writing a Int16 (short) and reading it gives the correct value.
///
[TestMethod]
public void T01_WriteAndReadInt16Variable()
{
Assert.IsTrue(plc.IsConnected, "Before executing this test, the plc must be connected. Check constructor.");
// To write a ushort i don't need any cast, only unboxing must be done
ushort val = 40000;
plc.Write("DB1.DBW0", val);
ushort result = (ushort)plc.Read("DB1.DBW0");
Assert.AreEqual(val, result, "A ushort goes from 0 to 64512");
// To write a short i need to convert it to UShort, then i need to reconvert the readed value to get
// the negative sign back
// Depending if i'm writing on a DWORD or on a DEC, i will see ushort or short value in the plc
short value = -100;
Assert.IsTrue(plc.IsConnected, "After connecting, IsConnected must be set to true");
plc.Write("DB1.DBW0", value.ConvertToUshort());
short result2 = ((ushort)plc.Read("DB1.DBW0")).ConvertToShort();
Assert.AreEqual(value, result2, "A short goes from -32767 to 32766");
}
///
/// Read/Write a single Int32 or UInt32 with a single request.
/// Test that writing a UInt32 (uint) and reading it gives the correct value.
/// Test also that writing a Int32 (int) and reading it gives the correct value.
///
[TestMethod]
public void T02_WriteAndReadInt32Variable()
{
Assert.IsTrue(plc.IsConnected, "Before executing this test, the plc must be connected. Check constructor.");
// To write a uint I don't need any cast, only unboxing must be done
uint val = 1000;
plc.Write("DB1.DBD40", val);
uint result = (uint)plc.Read("DB1.DBD40");
Assert.AreEqual(val, result);
// To write a int I need to convert it to uint, then I need to reconvert the readed value to get
// the negative sign back
// Depending if I'm writing on a DBD or on a LONG, I will see uint or int value in the plc
int value = -60000;
plc.Write("DB1.DBD60", value);
int result2 = ((uint)plc.Read("DB1.DBD60")).ConvertToInt();
Assert.AreEqual(value, result2);
}
///
/// Read/Write a single REAL with a single request.
/// Test that writing a double and reading it gives the correct value.
///
[TestMethod]
public void T03_WriteAndReadRealVariables()
{
Assert.IsTrue(plc.IsConnected, "Before executing this test, the plc must be connected. Check constructor.");
// Reading and writing a double is quite complicated, because it needs to be converted to DWord before the write,
// then reconvert to double after the read.
double val = 35.687;
plc.Write("DB1.DBD40", val.ConvertToUInt());
double result = ((uint)plc.Read("DB1.DBD40")).ConvertToDouble();
Assert.AreEqual(val, Math.Round(result, 3)); // float lose precision, so i need to round it
}
///
/// Read/Write a class that has the same properties of a DB with the same field in the same order
///
[TestMethod]
public void T04_ReadAndWriteClass()
{
Assert.IsTrue(plc.IsConnected, "Before executing this test, the plc must be connected. Check constructor.");
TestClass tc = new TestClass();
tc.BitVariable00 = true;
tc.BitVariable10 = true;
tc.DIntVariable = -100000;
tc.IntVariable = -15000;
tc.RealVariable = -154.789;
tc.DWordVariable = 850;
plc.WriteClass(tc, DB2);
TestClass tc2 = new TestClass();
// Values that are read from a class are stored inside the class itself, that is passed by reference
plc.ReadClass(tc2, DB2);
Assert.AreEqual(tc.BitVariable00, tc2.BitVariable00);
Assert.AreEqual(tc.BitVariable10, tc2.BitVariable10);
Assert.AreEqual(tc.DIntVariable, tc2.DIntVariable);
Assert.AreEqual(tc.IntVariable, tc2.IntVariable);
Assert.AreEqual(tc.RealVariable, Math.Round(tc2.RealVariable, 3));
Assert.AreEqual(tc.DWordVariable, tc2.DWordVariable);
}
///
/// Read/Write a struct that has the same properties of a DB with the same field in the same order
///
[TestMethod]
public void T05_ReadAndWriteStruct()
{
Assert.IsTrue(plc.IsConnected, "Before executing this test, the plc must be connected. Check constructor.");
TestStruct tc = new TestStruct();
tc.BitVariable00 = true;
tc.BitVariable10 = true;
tc.DIntVariable = -100000;
tc.IntVariable = -15000;
tc.RealVariable = -154.789;
tc.DWordVariable = 850;
plc.WriteStruct(tc, DB2);
// Values that are read from a struct are stored in a new struct, returned by the funcion ReadStruct
TestStruct tc2 = (TestStruct)plc.ReadStruct(typeof(TestStruct), DB2);
Assert.AreEqual(tc.BitVariable00, tc2.BitVariable00);
Assert.AreEqual(tc.BitVariable10, tc2.BitVariable10);
Assert.AreEqual(tc.DIntVariable, tc2.DIntVariable);
Assert.AreEqual(tc.IntVariable, tc2.IntVariable);
Assert.AreEqual(tc.RealVariable, Math.Round(tc2.RealVariable, 3));
Assert.AreEqual(tc.DWordVariable, tc2.DWordVariable);
}
#endregion
#region Private methods
private static void ShutDownServiceS7oiehsx64()
{
try
{
ServiceController sc = new ServiceController("s7oiehsx64");
switch (sc.Status)
{
case ServiceControllerStatus.Running:
sc.Stop();
break;
}
}
catch { } // service not found
}
#endregion
}
}