diff --git a/S7.Net/PlcAsynchronous.cs b/S7.Net/PlcAsynchronous.cs
index 387e610..ada92cf 100644
--- a/S7.Net/PlcAsynchronous.cs
+++ b/S7.Net/PlcAsynchronous.cs
@@ -79,11 +79,7 @@ namespace S7.Net
                 throw new WrongNumberOfBytesException("Not enough data received in response to Communication Setup");
 
             // TODO: check if this should not rather be UInt16.
-            MaxPDUSize = Types.Int.FromByteArray(s7data, 18);
-            if (MaxPDUSize <= 0 )
-            {
-                throw new PlcException(ErrorCode.ConnectionError, "Communication Setup resulted in non-positive PDU size.");
-            }
+            MaxPDUSize = (short)(s7data[18] * 256 + s7data[19]);
         }
 
 
diff --git a/S7.Net/Types/Int.cs b/S7.Net/Types/Int.cs
index d16d0fd..5489691 100644
--- a/S7.Net/Types/Int.cs
+++ b/S7.Net/Types/Int.cs
@@ -10,15 +10,15 @@ namespace S7.Net.Types
         /// <summary>
         /// Converts a S7 Int (2 bytes) to short (Int16)
         /// </summary>
-        public static short FromByteArray(byte[] bytes, int offset = 0)
+        public static short FromByteArray(byte[] bytes)
         {
-            if (bytes.Length < offset + 2)
+            if (bytes.Length != 2)
             {
-                throw new ArgumentException($"Wrong number of bytes. Bytes array must contain at least {offset+2} bytes.");
+                throw new ArgumentException("Wrong number of bytes. Bytes array must contain 2 bytes.");
             }
             // bytes[0] -> HighByte
             // bytes[1] -> LowByte
-            return (short)(bytes[offset + 1] | (bytes[offset + 0] << 8));
+            return (short)((int)(bytes[1]) | ((int)(bytes[0]) << 8));
         }