diff --git a/S7.Net/PLCHelpers.cs b/S7.Net/PLCHelpers.cs
index 2286264..9325f8a 100644
--- a/S7.Net/PLCHelpers.cs
+++ b/S7.Net/PLCHelpers.cs
@@ -1,4 +1,5 @@
-using S7.Net.Types;
+using S7.Net.Helper;
+using S7.Net.Types;
 using System;
 using System.Collections.Generic;
 using System.Linq;
@@ -13,21 +14,18 @@ namespace S7.Net
         /// </summary>
         /// <param name="amount"></param>
         /// <returns></returns>
-        private ByteArray ReadHeaderPackage(int amount = 1)
+        private void BuildHeaderPackage(System.IO.MemoryStream stream, int amount = 1)
         {
             //header size = 19 bytes
-            var package = new Types.ByteArray(19);
-            package.Add(new byte[] { 0x03, 0x00 });
+            stream.WriteByteArray(new byte[] { 0x03, 0x00 });
             //complete package size
-            package.Add(Types.Int.ToByteArray((short)(19 + (12 * amount))));
-            package.Add(new byte[] { 0x02, 0xf0, 0x80, 0x32, 0x01, 0x00, 0x00, 0x00, 0x00 });
+            stream.WriteByteArray(Types.Int.ToByteArray((short)(19 + (12 * amount))));
+            stream.WriteByteArray(new byte[] { 0x02, 0xf0, 0x80, 0x32, 0x01, 0x00, 0x00, 0x00, 0x00 });
             //data part size
-            package.Add(Types.Word.ToByteArray((ushort)(2 + (amount * 12))));
-            package.Add(new byte[] { 0x00, 0x00, 0x04 });
+            stream.WriteByteArray(Types.Word.ToByteArray((ushort)(2 + (amount * 12))));
+            stream.WriteByteArray(new byte[] { 0x00, 0x00, 0x04 });
             //amount of requests
-            package.Add((byte)amount);
-
-            return package;
+            stream.WriteByte((byte)amount);
         }
 
         /// <summary>
@@ -39,39 +37,36 @@ namespace S7.Net
         /// <param name="startByteAdr">Start address of the byte</param>
         /// <param name="count">Number of bytes to be read</param>
         /// <returns></returns>
-        private ByteArray CreateReadDataRequestPackage(DataType dataType, int db, int startByteAdr, int count = 1)
+        private void BuildReadDataRequestPackage(System.IO.MemoryStream stream, DataType dataType, int db, int startByteAdr, int count = 1)
         {
             //single data req = 12
-            var package = new Types.ByteArray(12);
-            package.Add(new byte[] { 0x12, 0x0a, 0x10 });
+            stream.WriteByteArray(new byte[] { 0x12, 0x0a, 0x10 });
             switch (dataType)
             {
                 case DataType.Timer:
                 case DataType.Counter:
-                    package.Add((byte)dataType);
+                    stream.WriteByte((byte)dataType);
                     break;
                 default:
-                    package.Add(0x02);
+                    stream.WriteByte(0x02);
                     break;
             }
 
-            package.Add(Word.ToByteArray((ushort)(count)));
-            package.Add(Word.ToByteArray((ushort)(db)));
-            package.Add((byte)dataType);
+            stream.WriteByteArray(Word.ToByteArray((ushort)(count)));
+            stream.WriteByteArray(Word.ToByteArray((ushort)(db)));
+            stream.WriteByte((byte)dataType);
             var overflow = (int)(startByteAdr * 8 / 0xffffU); // handles words with address bigger than 8191
-            package.Add((byte)overflow);
+            stream.WriteByte((byte)overflow);
             switch (dataType)
             {
                 case DataType.Timer:
                 case DataType.Counter:
-                    package.Add(Types.Word.ToByteArray((ushort)(startByteAdr)));
+                    stream.WriteByteArray(Types.Word.ToByteArray((ushort)(startByteAdr)));
                     break;
                 default:
-                    package.Add(Types.Word.ToByteArray((ushort)((startByteAdr) * 8)));
+                    stream.WriteByteArray(Types.Word.ToByteArray((ushort)((startByteAdr) * 8)));
                     break;
             }
-
-            return package;
         }
 
         /// <summary>
diff --git a/S7.Net/PlcAsynchronous.cs b/S7.Net/PlcAsynchronous.cs
index 61727ae..35265c8 100644
--- a/S7.Net/PlcAsynchronous.cs
+++ b/S7.Net/PlcAsynchronous.cs
@@ -222,15 +222,16 @@ namespace S7.Net
             {
                 // first create the header
                 int packageSize = 19 + (dataItems.Count * 12);
-                ByteArray package = new ByteArray(packageSize);
-                package.Add(ReadHeaderPackage(dataItems.Count));
+                var package = new System.IO.MemoryStream(packageSize);
+                BuildHeaderPackage(package, dataItems.Count);
                 // package.Add(0x02);  // datenart
                 foreach (var dataItem in dataItems)
                 {
-                    package.Add(CreateReadDataRequestPackage(dataItem.DataType, dataItem.DB, dataItem.StartByteAdr, VarTypeToByteLength(dataItem.VarType, dataItem.Count)));
+                    BuildReadDataRequestPackage(package, dataItem.DataType, dataItem.DB, dataItem.StartByteAdr, VarTypeToByteLength(dataItem.VarType, dataItem.Count));
                 }
 
-                await stream.WriteAsync(package.Array, 0, package.Array.Length);
+                var dataToSend = package.ToArray();
+                await stream.WriteAsync(dataToSend, 0, dataToSend.Length);
 
                 var s7data = await COTP.TSDU.ReadAsync(stream); //TODO use Async
                 if (s7data == null || s7data[14] != 0xff)
@@ -390,13 +391,14 @@ namespace S7.Net
             byte[] bytes = new byte[count];
 
             // first create the header
-            int packageSize = 31;
-            ByteArray package = new ByteArray(packageSize);
-            package.Add(ReadHeaderPackage());
+            int packageSize = 31; 
+            var package = new System.IO.MemoryStream(packageSize);
+            BuildHeaderPackage(package);
             // package.Add(0x02);  // datenart
-            package.Add(CreateReadDataRequestPackage(dataType, db, startByteAdr, count));
+            BuildReadDataRequestPackage(package, dataType, db, startByteAdr, count);
 
-            await stream.WriteAsync(package.Array, 0, package.Array.Length);
+            var dataToSend = package.ToArray();
+            await stream.WriteAsync(dataToSend, 0, dataToSend.Length);
 
             var s7data = await COTP.TSDU.ReadAsync(stream);
             AssertReadResponse(s7data, count);
diff --git a/S7.Net/PlcSynchronous.cs b/S7.Net/PlcSynchronous.cs
index 367c572..f73bd6f 100644
--- a/S7.Net/PlcSynchronous.cs
+++ b/S7.Net/PlcSynchronous.cs
@@ -349,12 +349,13 @@ namespace S7.Net
             {
                 // first create the header
                 int packageSize = 31;
-                ByteArray package = new ByteArray(packageSize);
-                package.Add(ReadHeaderPackage());
+                var package = new System.IO.MemoryStream(packageSize);
+                BuildHeaderPackage(package);
                 // package.Add(0x02);  // datenart
-                package.Add(CreateReadDataRequestPackage(dataType, db, startByteAdr, count));
+                BuildReadDataRequestPackage(package, dataType, db, startByteAdr, count);
 
-                stream.Write(package.Array, 0, package.Array.Length);
+                var dataToSend = package.ToArray();
+                stream.Write(dataToSend, 0, dataToSend.Length);
 
                 var s7data = COTP.TSDU.Read(stream);
                 AssertReadResponse(s7data, count);
@@ -516,15 +517,16 @@ namespace S7.Net
             {
                 // first create the header
                 int packageSize = 19 + (dataItems.Count * 12);
-                ByteArray package = new ByteArray(packageSize);
-                package.Add(ReadHeaderPackage(dataItems.Count));
+                var package = new System.IO.MemoryStream(packageSize);
+                BuildHeaderPackage(package, dataItems.Count);
                 // package.Add(0x02);  // datenart
                 foreach (var dataItem in dataItems)
                 {
-                    package.Add(CreateReadDataRequestPackage(dataItem.DataType, dataItem.DB, dataItem.StartByteAdr, VarTypeToByteLength(dataItem.VarType, dataItem.Count)));
+                    BuildReadDataRequestPackage(package, dataItem.DataType, dataItem.DB, dataItem.StartByteAdr, VarTypeToByteLength(dataItem.VarType, dataItem.Count));
                 }
 
-                stream.Write(package.Array, 0, package.Array.Length);
+                var dataToSend = package.ToArray();
+                stream.Write(dataToSend, 0, dataToSend.Length);
 
                 var s7data = COTP.TSDU.Read(stream); //TODO use Async
                 if (s7data == null || s7data[14] != 0xff)