Snap7 read INT value

Hi,

I allways used libnodave, but now trying snap7.

However this code doesn't work:

int intValue = 0;
int Area = 0x84;
int DBNumber = Convert.ToInt16(txtDBnr1.Text);
int Start = Convert.ToInt16(txtDBitem1.Text);
int Amount = 1;
int WordLen = 0x04;
Buffer = new byte[2];
intValue = Client.ReadArea(Area, DBNumber, Start, Amount, WordLen, Buffer);
int value = Convert.ToInt16(S7.GetLIntAt(Buffer, 0));
txtRcvVar1.Text = Convert.ToString(value);


Exception thrown: 'System.IndexOutOfRangeException'

A length error somewhere ?

Test

Just made the buffer bigger, but then I get the exception that the value received is to big for INT32 ???

int intValue = 0;
int Area = 0x84;
int DBNumber = Convert.ToInt16(txtDBnr1.Text);
int Start = Convert.ToInt16(txtDBitem1.Text);
int Amount = 1;
int WordLen = 0x04;
Buffer = new byte[20];
intValue = Client.ReadArea(Area, DBNumber, Start, Amount, WordLen, Buffer);
int value = Convert.ToInt32(S7.GetLIntAt(Buffer, 0));
txtRcvVar1.Text = Convert.ToString(value);

Does your exception reporting indicate the line of code where the exception occurs?

You are using S7.GetLIntAt, shouldn't this be S7.GetIntAt?

Libnodave

I returned to libnodave, I don't have probs there.

Kind regards,
G

I use libnodave and Snap7(using Delphi pascal) and don't have problems with either.

A strange thread and actions taken.

I use Snap7 (Sharp7) nowadays and find it easier, although very similar. Snap has already the PLC simulator (Client, Server) pre compiled to verify communications. But, as proven here, the difficulties and about 90% of code is not related to whatever library is used. Instead it's the stuff around. Exceptions are of great use and error handling is always the most lines of code.