diff --git a/Sharp7.Rx/Extensions/OperandExtensions.cs b/Sharp7.Rx/Extensions/OperandExtensions.cs
new file mode 100644
index 0000000..c78cfa5
--- /dev/null
+++ b/Sharp7.Rx/Extensions/OperandExtensions.cs
@@ -0,0 +1,17 @@
+using Sharp7.Rx.Enums;
+
+namespace Sharp7.Rx.Extensions;
+
+internal static class OperandExtensions
+{
+    public static S7Area ToArea(this Operand operand) =>
+        operand switch
+        {
+            Operand.Input => S7Area.PE,
+            Operand.Output => S7Area.PA,
+            Operand.Marker => S7Area.MK,
+            Operand.Db => S7Area.DB,
+            _ => throw new ArgumentOutOfRangeException(nameof(operand), operand, null)
+        };
+
+}
diff --git a/Sharp7.Rx/Sharp7Connector.cs b/Sharp7.Rx/Sharp7Connector.cs
index b983c46..7adfa2e 100644
--- a/Sharp7.Rx/Sharp7Connector.cs
+++ b/Sharp7.Rx/Sharp7Connector.cs
@@ -146,10 +146,9 @@ namespace Sharp7.Rx
 
             var buffer = new byte[bytesToRead];
 
-            var area = FromOperand(operand);
 
             var result =
-                await Task.Factory.StartNew(() => sharp7.ReadArea(area, dBNr, startByteAddress, bytesToRead, S7Consts.S7WLByte, buffer), token, TaskCreationOptions.None, scheduler);
+                await Task.Factory.StartNew(() => sharp7.ReadArea(operand.ToArea(), dBNr, startByteAddress, bytesToRead, S7WordLength.Byte, buffer), token, TaskCreationOptions.None, scheduler);
             token.ThrowIfCancellationRequested();
 
             if (result != 0)
@@ -170,7 +169,7 @@ namespace Sharp7.Rx
 
             var offsetStart = (startByteAddress * 8) + bitAdress;
 
-            var result = await Task.Factory.StartNew(() => sharp7.WriteArea(FromOperand(operand), dbNr, offsetStart, 1, S7Consts.S7WLBit, buffer), token, TaskCreationOptions.None, scheduler);
+            var result = await Task.Factory.StartNew(() => sharp7.WriteArea(operand.ToArea(), dbNr, offsetStart, 1, S7WordLength.Bit, buffer), token, TaskCreationOptions.None, scheduler);
             token.ThrowIfCancellationRequested();
 
             if (result != 0)
@@ -186,7 +185,7 @@ namespace Sharp7.Rx
         {
             EnsureConnectionValid();
 
-            var result = await Task.Factory.StartNew(() => sharp7.WriteArea(FromOperand(operand), dBNr, startByteAdress, data.Length, S7Consts.S7WLByte, data), token, TaskCreationOptions.None, scheduler);
+            var result = await Task.Factory.StartNew(() => sharp7.WriteArea(operand.ToArea(), dBNr, startByteAdress, data.Length, S7WordLength.Byte, data), token, TaskCreationOptions.None, scheduler);
             token.ThrowIfCancellationRequested();
 
             if (result != 0)
@@ -258,23 +257,6 @@ namespace Sharp7.Rx
             return false;
         }
 
-        private int FromOperand(Operand operand)
-        {
-            switch (operand)
-            {
-                case Operand.Input:
-                    return S7Consts.S7AreaPE;
-                case Operand.Output:
-                    return S7Consts.S7AreaPA;
-                case Operand.Marker:
-                    return S7Consts.S7AreaMK;
-                case Operand.Db:
-                    return S7Consts.S7AreaDB;
-                default:
-                    throw new ArgumentOutOfRangeException(nameof(operand), operand, null);
-            }
-        }
-
         private async Task<bool> Reconnect()
         {
             await CloseConnection();
@@ -294,4 +276,4 @@ namespace Sharp7.Rx
             Dispose(false);
         }
     }
-}
\ No newline at end of file
+}