PLC: Address out of range.

[Ahmed2017Saad]

Hello I got this error each time I tried to write data to the last address of the Data block, the plc is s7-300

the address I tried to write to is DB63.DBW50, The data block length from the PLC is 52 bytes, and I can access this address from PLC successfully

also, I tried to write to the last word of another data block I got the same error

S7.Net.PlcException HResult=0x80131500 Message=Received error from PLC: Address out of range. Source=S7.Net StackTrace: at S7.Net.Plc.WriteBytesWithASingleRequest(DataType dataType, Int32 db, Int32 startByteAdr, Byte[] value, Int32 dataOffset, Int32 count) at S7.Net.Plc.WriteBytes(DataType dataType, Int32 db, Int32 startByteAdr, Byte[] value) at S7.Net.Plc.Write(DataType dataType, Int32 db, Int32 startByteAdr, Object value, Int32 bitAdr) at S7.Net.Plc.Write(String variable, Object value) at WindowsFormsApp2.Form1.btnDelet_Click(Object sender, EventArgs e) at System.Windows.Forms.Control.OnClick(EventArgs e) at System.Windows.Forms.Button.OnClick(EventArgs e) at System.Windows.Forms.Button.OnMouseUp(MouseEventArgs mevent) at System.Windows.Forms.Control.WmMouseUp(Message& m, MouseButtons button, Int32 clicks) at System.Windows.Forms.Control.WndProc(Message& m) at System.Windows.Forms.ButtonBase.WndProc(Message& m) at System.Windows.Forms.Button.WndProc(Message& m) at System.Windows.Forms.Control.ControlNativeWindow.OnMessage(Message& m) at System.Windows.Forms.Control.ControlNativeWindow.WndProc(Message& m) at System.Windows.Forms.NativeWindow.DebuggableCallback(IntPtr hWnd, Int32 msg, IntPtr wparam, IntPtr lparam) at System.Windows.Forms.UnsafeNativeMethods.DispatchMessageW(MSG& msg) at System.Windows.Forms.Application.ComponentManager.System.Windows.Forms.UnsafeNativeMethods.IMsoComponentManager.FPushMessageLoop(IntPtr dwComponentID, Int32 reason, Int32 pvLoopData) at System.Windows.Forms.Application.ThreadContext.RunMessageLoopInner(Int32 reason, ApplicationContext context) at System.Windows.Forms.Application.ThreadContext.RunMessageLoop(Int32 reason, ApplicationContext context) at System.Windows.Forms.Application.Run(Form mainForm) at WindowsFormsApp2.Program.Main()

This exception was originally thrown at this call stack: [External Code]

Inner Exception 1: Exception: Received error from PLC: Address out of range.

[mycroes]

Could it be you're writing an int while the plc type is word (short in C#)?

[Ahmed2017Saad]

I have tested it after converting the data to ushort, and it is working

but another issue noticed

i'm trying to write to DB63.DBB50 byt using plc.Write(DB63.DBB50, (ushort)10);

when monitoring from PLC the byte is still zero as shown below

[mycroes]

You should cast to byte instead of ushort when you want to write a byte.

[Ahmed2017Saad]

i have updated the casting to byte, it wrote to the correct plc address but the data is wrong i was trying to write 10 please check the Wireshark data and plc data please check the address DB63.DBB0 it is 2 instead of 10

[Ahmed2017Saad]

sorry for my mistake, the plc was writing at the same time to the same address, that is what made the data changes