diff --git a/Apex7000_BillValidator/DataContracts.cs b/Apex7000_BillValidator/DataContracts.cs
index 3a27a2d..6c34252 100644
--- a/Apex7000_BillValidator/DataContracts.cs
+++ b/Apex7000_BillValidator/DataContracts.cs
@@ -55,8 +55,7 @@ public struct Response
     public struct Request
     {
         public static readonly byte[] BaseMessage = { 0x02, 0x08, 0x10, 0x7F, 0x10, 0x00, 0x03 };
-        public static readonly byte[] Ack =         { 0x02, 0x08, 0x10, 0x7F, 0x10, 0x00, 0x03 };
-        //public static readonly byte[] Ack = { 0x02, 0x08, 0x11, 0x7F, 0x10, 0x00, 0x03 };
+        public static readonly byte[] Ack = { 0x02, 0x08, 0x11, 0x7F, 0x10, 0x00, 0x03 };
         public static readonly byte[] Escrow = { 0x02, 0x08, 0x11, 0x7F, 0x10, 0x00, 0x03 };
         public static readonly byte[] Stack = { 0x02, 0x08, 0x11, 0x7F, 0x30, 0x00, 0x03 };
         public static readonly byte[] Reject = { 0x02, 0x08, 0x11, 0x7F, 0x50, 0x00, 0x03 };