From 4fcab9a1671606a6028df6e5f1e460d1ddff9a8f Mon Sep 17 00:00:00 2001
From: Michael Croes <mycroes@gmail.com>
Date: Wed, 11 Jul 2018 22:19:02 +0200
Subject: [PATCH 1/3] Fix VarTypeToByteLength for bit arrays

---
 S7.Net/PLCHelpers.cs | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/S7.Net/PLCHelpers.cs b/S7.Net/PLCHelpers.cs
index 803d349..e67d394 100644
--- a/S7.Net/PLCHelpers.cs
+++ b/S7.Net/PLCHelpers.cs
@@ -172,7 +172,7 @@ namespace S7.Net
             switch (varType)
             {
                 case VarType.Bit:
-                    return varCount; //TODO
+                    return varCount + 7 / 8;
                 case VarType.Byte:
                     return (varCount < 1) ? 1 : varCount;
                 case VarType.String:

From b3cb45de37bf6983780b9960265abaef0be398b4 Mon Sep 17 00:00:00 2001
From: Michael Croes <mycroes@gmail.com>
Date: Wed, 11 Jul 2018 22:30:10 +0200
Subject: [PATCH 2/3] Add ToBitArray overload with length

---
 S7.Net/Types/Bit.cs | 26 +++++++++++++++++++++-----
 1 file changed, 21 insertions(+), 5 deletions(-)

diff --git a/S7.Net/Types/Bit.cs b/S7.Net/Types/Bit.cs
index 5f00476..5214fd9 100644
--- a/S7.Net/Types/Bit.cs
+++ b/S7.Net/Types/Bit.cs
@@ -1,4 +1,5 @@
-using System.Collections;
+using System;
+using System.Collections;
 
 namespace S7.Net.Types
 {
@@ -16,12 +17,27 @@ namespace S7.Net.Types
         }
 
         /// <summary>
-        /// Converts an array of bytes to a BitArray
+        /// Converts an array of bytes to a BitArray.
         /// </summary>
-        public static BitArray ToBitArray(byte[] bytes)
+        /// <param name="bytes">The bytes to convert.</param>
+        /// <returns>A BitArray with the same number of bits and equal values as <paramref name="bytes"/>.</returns>
+        public static BitArray ToBitArray(byte[] bytes) => ToBitArray(bytes, bytes.Length * 8);
+
+        /// <summary>
+        /// Converts an array of bytes to a BitArray.
+        /// </summary>
+        /// <param name="bytes">The bytes to convert.</param>
+        /// <param name="length">The number of bits to return.</param>
+        /// <returns>A BitArray with <paramref name="length"/> bits.</returns>
+        public static BitArray ToBitArray(byte[] bytes, int length)
         {
-            BitArray bitArr = new BitArray(bytes);
-            return bitArr;
+            if (length > bytes.Length * 8) throw new ArgumentException($"Not enough data in bytes to return {length} bits.", nameof(bytes));
+
+            var bitArr = new BitArray(bytes);
+            var bools = new bool[length];
+            for (var i = 0; i < length; i++) bools[i] = bitArr[i];
+
+            return new BitArray(bools);
         }
     }
 }

From 6a84b6f1247806eb5f392edae28f6141cec4bc4a Mon Sep 17 00:00:00 2001
From: Michael Croes <mycroes@gmail.com>
Date: Wed, 11 Jul 2018 22:30:53 +0200
Subject: [PATCH 3/3] Use ToBitArray overload with length in ParseBytes

---
 S7.Net/PLCHelpers.cs | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/S7.Net/PLCHelpers.cs b/S7.Net/PLCHelpers.cs
index e67d394..2ea37cd 100644
--- a/S7.Net/PLCHelpers.cs
+++ b/S7.Net/PLCHelpers.cs
@@ -145,7 +145,7 @@ namespace S7.Net
                     }
                     else
                     {
-                        return Bit.ToBitArray(bytes);
+                        return Bit.ToBitArray(bytes, varCount);
                     }
                 case VarType.DateTime:
                     if (varCount == 1)