From 70506e7dba1436788c39501662bc3a341494e220 Mon Sep 17 00:00:00 2001
From: Michael Croes <mycroes@gmail.com>
Date: Wed, 10 Oct 2018 21:41:52 +0200
Subject: [PATCH] Throw InvalidDataException in Open(Async)

---
 S7.Net/PlcAsynchronous.cs | 13 ++++++++-----
 S7.Net/PlcSynchronous.cs  | 13 ++++++++-----
 2 files changed, 16 insertions(+), 10 deletions(-)

diff --git a/S7.Net/PlcAsynchronous.cs b/S7.Net/PlcAsynchronous.cs
index 1c28503..fe3c552 100644
--- a/S7.Net/PlcAsynchronous.cs
+++ b/S7.Net/PlcAsynchronous.cs
@@ -25,16 +25,19 @@ namespace S7.Net
             var response = await COTP.TPDU.ReadAsync(stream);
             if (response.PDUType != 0xd0) //Connect Confirm
             {
-                throw new WrongNumberOfBytesException("Waiting for COTP connect confirm");
+                throw new InvalidDataException("Error reading Connection Confirm", response.TPkt.Data, 1, 0x0d);
             }
 
             await stream.WriteAsync(GetS7ConnectionSetup(), 0, 25);
 
             var s7data = await COTP.TSDU.ReadAsync(stream);
-            if (s7data == null || s7data[1] != 0x03) //Check for S7 Ack Data
-            {
-                throw new WrongNumberOfBytesException("Waiting for S7 connection setup");
-            }
+            if (s7data == null)
+                throw new WrongNumberOfBytesException("No data received in response to Communication Setup");
+
+            //Check for S7 Ack Data
+            if (s7data[1] != 0x03)
+                throw new InvalidDataException("Error reading Communication Setup response", s7data, 1, 0x03);
+
             MaxPDUSize = (short)(s7data[18] * 256 + s7data[19]);
         }
 
diff --git a/S7.Net/PlcSynchronous.cs b/S7.Net/PlcSynchronous.cs
index 4c30636..bdc40bf 100644
--- a/S7.Net/PlcSynchronous.cs
+++ b/S7.Net/PlcSynchronous.cs
@@ -23,16 +23,19 @@ namespace S7.Net
                 var response = COTP.TPDU.Read(stream);
                 if (response.PDUType != 0xd0) //Connect Confirm
                 {
-                    throw new WrongNumberOfBytesException("Waiting for COTP connect confirm");
+                    throw new InvalidDataException("Error reading Connection Confirm", response.TPkt.Data, 1, 0x0d);
                 }
 
                 stream.Write(GetS7ConnectionSetup(), 0, 25);
 
                 var s7data = COTP.TSDU.Read(stream);
-                if (s7data == null || s7data[1] != 0x03) //Check for S7 Ack Data
-                {
-                    throw new WrongNumberOfBytesException("Waiting for S7 connection setup");
-                }
+                if (s7data == null)
+                    throw new WrongNumberOfBytesException("No data received in response to Communication Setup");
+
+                //Check for S7 Ack Data
+                if (s7data[1] != 0x03)
+                    throw new InvalidDataException("Error reading Communication Setup response", s7data, 1, 0x03);
+
                 MaxPDUSize = (short)(s7data[18] * 256 + s7data[19]);
             }
             catch (Exception exc)