From 6cff54514fe0dc533046a10b3e06097918135015 Mon Sep 17 00:00:00 2001
From: Marcos Pereira <marcos.pereira@tecwash.pt>
Date: Tue, 23 Feb 2016 09:09:12 +0000
Subject: [PATCH] Read struct and multiple bytes from a specific start bytes
 address.

---
 S7.Net.Core/PLC.cs | 16 +++++++++++++---
 S7.Net/PLC.cs      | 16 +++++++++++++---
 2 files changed, 26 insertions(+), 6 deletions(-)

diff --git a/S7.Net.Core/PLC.cs b/S7.Net.Core/PLC.cs
index 7936417..f7d32a9 100644
--- a/S7.Net.Core/PLC.cs
+++ b/S7.Net.Core/PLC.cs
@@ -507,11 +507,16 @@ namespace S7.Net
         }
 
         public object ReadStruct(Type structType, int db)
+        {
+            return ReadStruct(structType, db, 0);
+        }
+
+        public object ReadStruct(Type structType, int db, int startByteAdr)
         {
             int numBytes = Types.Struct.GetStructSize(structType);
             // now read the package
-            List<byte> resultBytes = ReadMultipleBytes(numBytes, db);
-            
+            List<byte> resultBytes = ReadMultipleBytes(numBytes, db, startByteAdr);
+
             // and decode it
             return Types.Struct.FromBytes(structType, resultBytes.ToArray());
         }
@@ -851,9 +856,14 @@ namespace S7.Net
         /// <param name="db"></param>
         /// <returns></returns>
         private List<byte> ReadMultipleBytes(int numBytes, int db)
+        {
+            return ReadMultipleBytes(numBytes, db, 0);
+        }
+
+        private List<byte> ReadMultipleBytes(int numBytes, int db, int startByteAdr)
         {
             List<byte> resultBytes = new List<byte>();
-            int index = 0;
+            int index = startByteAdr;
             while (numBytes > 0)
             {
                 var maxToRead = (int)Math.Min(numBytes, 200);
diff --git a/S7.Net/PLC.cs b/S7.Net/PLC.cs
index 9374fe9..a0b4abf 100644
--- a/S7.Net/PLC.cs
+++ b/S7.Net/PLC.cs
@@ -507,11 +507,16 @@ namespace S7.Net
         }
 
         public object ReadStruct(Type structType, int db)
+        {
+            return ReadStruct(structType, db, 0);
+        }
+
+        public object ReadStruct(Type structType, int db, int startByteAdr)
         {
             int numBytes = Types.Struct.GetStructSize(structType);
             // now read the package
-            List<byte> resultBytes = ReadMultipleBytes(numBytes, db);
-            
+            List<byte> resultBytes = ReadMultipleBytes(numBytes, db, startByteAdr);
+
             // and decode it
             return Types.Struct.FromBytes(structType, resultBytes.ToArray());
         }
@@ -851,9 +856,14 @@ namespace S7.Net
         /// <param name="db"></param>
         /// <returns></returns>
         private List<byte> ReadMultipleBytes(int numBytes, int db)
+        {
+            return ReadMultipleBytes(numBytes, db, 0);
+        }
+
+        private List<byte> ReadMultipleBytes(int numBytes, int db, int startByteAdr)
         {
             List<byte> resultBytes = new List<byte>();
-            int index = 0;
+            int index = startByteAdr;
             while (numBytes > 0)
             {
                 var maxToRead = (int)Math.Min(numBytes, 200);