diff --git a/S7.Net.UnitTest/ConnectionRequestTest.cs b/S7.Net.UnitTest/ConnectionRequestTest.cs
index db7cabf..440a962 100644
--- a/S7.Net.UnitTest/ConnectionRequestTest.cs
+++ b/S7.Net.UnitTest/ConnectionRequestTest.cs
@@ -75,7 +75,7 @@ namespace S7.Net.UnitTest
                 destTsap1, destTsap2, //Destination TASP
                 192, //Parameter Code (tpdu-size)
                 1, //Parameter Length
-                11 //TPDU Size (2^11 = 2048)
+                10 //TPDU Size (2^11 = 2048)
             };
         }
     }
diff --git a/S7.Net/PLCHelpers.cs b/S7.Net/PLCHelpers.cs
index 30aaaf0..d4e5f18 100644
--- a/S7.Net/PLCHelpers.cs
+++ b/S7.Net/PLCHelpers.cs
@@ -186,7 +186,7 @@ namespace S7.Net
         private byte[] GetS7ConnectionSetup()
         {
             return new byte[] {  3, 0, 0, 25, 2, 240, 128, 50, 1, 0, 0, 255, 255, 0, 8, 0, 0, 240, 0, 0, 3, 0, 3,
-                    7, 128 //Try 1920 PDU Size. Same as libnodave.
+                    3, 192 // Use 960 PDU size
             };
         }
 
diff --git a/S7.Net/Protocol/ConnectionRequest.cs b/S7.Net/Protocol/ConnectionRequest.cs
index 0535cb2..f0a4567 100644
--- a/S7.Net/Protocol/ConnectionRequest.cs
+++ b/S7.Net/Protocol/ConnectionRequest.cs
@@ -21,7 +21,7 @@ namespace S7.Net.Protocol
                     3, 0,   //Destination TASP
                     192,    //Parameter Code (tpdu-size)
                     1,      //Parameter Length
-                    11      //TPDU Size (2^11 = 2048)
+                    10      //TPDU Size (2^10 = 1024)
                 };
 
             switch (cpu)