Reading from address higher than 8096

[Skokan44]

Hi,

I am trying to read a data from a DB on S7-1200 station. I ran into problem and so far wasn't able to solve it. Apparently there is some problem, when I am reading data from position higher then 8096. Is it possible or am I doing something wrong?

ushort address = (ushort) (StackAdress + 2*RecPtr); var o = _plc.Read(DataType.DataBlock, DataBlockIndex,address, VarType.Int, RecSize);¨

Thanks, Martin.

[mesta1]

Hi, are you using the NuGet version ? We updated the sources and solved the problem, but we still have to update NuGet. Try to download the latest sources and if you still have the problem, let me know.

[Skokan44]

Yes I was using the NuGet version, now it is working just fine. Thank you for your work!

[oiisamiio]

var overflow = (int)(startByteAdr * 8 / 0xffffU); // handles words with address bigger than 8191

still results in invalid data if startByteAdr < 8191 + Count > 8191 and data overlap. So better let requests result in an error if startByteAdr < 8191 but + Count > 8191?

[mesta1]

Please can you post the code to reproduce the issue?

[oiisamiio]

public ErrorCode Write(DataType dataType, int db, int startByteAdr, object value)

an example: if startByteAdr would be 8190 (DB1.DBD8190) and value length would be 4 bytes var overflow = (int)(startByteAdr * 8 / 0xffffU); // handles words with address bigger than 8191 var overflow would result in 0 address would overlap, request would overlap 0/1. Right?

Excuse my english

[mesta1]

I'll test it asap.

[oiisamiio]

think we need something like this:

if ((startByteAdr*8/0xffffU) == 0)
{
   if ((startByteAdr*8/0xffffU) + varCount > 0)
   {
      throw new Exception(ErrorCode.WrongVarFormat.ToString());
   }
}

[mesta1]

I don't think that throwing an error is a solution, but I still had no time to check this.

[mesta1]

I did some tests today, but I couldn't reproduce the problem. This is the code that I tested, also on a S7-300 and Step7.

 [TestMethod]
 public void T11_WriteDbd8190()
 {
     ushort val = 16384;
     plc.Write("DB2.DBW8190", val);
     var result = plc.Read("DB2.DBW8190");
     Assert.AreEqual((ushort)16384, result);
 }

 [TestMethod]
 public void T12_WriteDbd8190()
 {
     int val2 = 32000;
     plc.Write("DB2.DBD8190", val2);
     var result2 =  plc.Read("DB2.DBD8190");
     Assert.AreEqual((uint)32000, result2);
 }

[oiisamiio]

Sorry, did also some tests. Looks fine, no issue

Please Close Issue, Thanks

[mesta1]

No problem, thanks for your time.