Add S7 Time type (C# TimeSpan)

Adds the S7 TIME (IEC) type (32 bits long)
It is deserialized to C# TimeSpan and serialized as S7 DInt.

S7.Net.UnitTest/S7NetTestsAsync.cs

@@ -1006,7 +1006,7 @@ namespace S7.Net.UnitTest
             var db = 2;
             randomEngine.NextBytes(data);
 
-            cancellationSource.CancelAfter(TimeSpan.FromMilliseconds(5));
+            cancellationSource.CancelAfter(System.TimeSpan.FromMilliseconds(5));
             try
             {
                 await plc.WriteBytesAsync(DataType.DataBlock, db, 0, data, cancellationToken);
@@ -1045,7 +1045,7 @@ namespace S7.Net.UnitTest
             var db = 2;
             randomEngine.NextBytes(data.Span);
 
-            cancellationSource.CancelAfter(TimeSpan.FromMilliseconds(5));
+            cancellationSource.CancelAfter(System.TimeSpan.FromMilliseconds(5));
             try
             {
                 await plc.WriteBytesAsync(DataType.DataBlock, db, 0, data, cancellationToken);

S7.Net/Enums.cs

@@ -206,6 +206,11 @@
         /// <summary>
         /// DateTimeLong variable type
         /// </summary>
-        DateTimeLong
+        DateTimeLong,
+        
+        /// <summary>
+        /// S7 TIME variable type - serialized as S7 DInt and deserialized as C# TimeSpan 
+        /// </summary>
+        Time
     }
 }

S7.Net/PLCHelpers.cs

@@ -167,6 +167,15 @@ namespace S7.Net
                     {
                         return DateTimeLong.ToArray(bytes);
                     }
+                case VarType.Time:
+                    if (varCount == 1)
+                    {
+                        return TimeSpan.FromByteArray(bytes);
+                    }
+                    else
+                    {
+                        return TimeSpan.ToArray(bytes);
+                    }
                 default:
                     return null;
             }
@@ -200,6 +209,7 @@ namespace S7.Net
                 case VarType.DWord:
                 case VarType.DInt:
                 case VarType.Real:
+                case VarType.Time:
                     return varCount * 4;
                 case VarType.LReal:
                 case VarType.DateTime:

S7.Net/Types/TimeSpan.cs

@@ -0,0 +1,95 @@
+using System;
+using System.Collections.Generic;
+
+namespace S7.Net.Types
+{
+    public static class TimeSpan
+    {
+        /// <summary>
+        /// The minimum <see cref="T:System.TimeSpan"/> value supported by the specification.
+        /// </summary>
+        public static readonly System.TimeSpan SpecMinimumTimeSpan = System.TimeSpan.FromMilliseconds(int.MinValue);
+
+        /// <summary>
+        /// The maximum <see cref="T:System.TimeSpan"/> value supported by the specification.
+        /// </summary>
+        public static readonly System.TimeSpan SpecMaximumTimeSpan = System.TimeSpan.FromMilliseconds(int.MaxValue);
+
+        /// <summary>
+        /// Parses a <see cref="T:System.TimeSpan"/> value from bytes.
+        /// </summary>
+        /// <param name="bytes">Input bytes read from PLC.</param>
+        /// <returns>A <see cref="T:System.TimeSpan"/> object representing the value read from PLC.</returns>
+        /// <exception cref="ArgumentOutOfRangeException">Thrown when the length of
+        ///   <paramref name="bytes"/> is not 4 or any value in <paramref name="bytes"/>
+        ///   is outside the valid range of values.</exception>
+        public static System.TimeSpan FromByteArray(byte[] bytes)
+        {
+            var milliseconds = DInt.FromByteArray(bytes);
+            return System.TimeSpan.FromMilliseconds(milliseconds);
+        }
+
+        /// <summary>
+        /// Parses an array of <see cref="T:System.TimeSpan"/> values from bytes.
+        /// </summary>
+        /// <param name="bytes">Input bytes read from PLC.</param>
+        /// <returns>An array of <see cref="T:System.TimeSpan"/> objects representing the values read from PLC.</returns>
+        /// <exception cref="ArgumentOutOfRangeException">Thrown when the length of
+        ///   <paramref name="bytes"/> is not a multiple of 4 or any value in
+        ///   <paramref name="bytes"/> is outside the valid range of values.</exception>
+        public static System.TimeSpan[] ToArray(byte[] bytes)
+        {
+            const int singleTimeSpanLength = 4;
+            
+            if (bytes.Length % singleTimeSpanLength != 0)
+                throw new ArgumentOutOfRangeException(nameof(bytes), bytes.Length,
+                    $"Parsing an array of {nameof(System.TimeSpan)} requires a multiple of {singleTimeSpanLength} bytes of input data, input data is '{bytes.Length}' long.");
+
+            var cnt = bytes.Length / singleTimeSpanLength;
+            var result = new System.TimeSpan[bytes.Length / singleTimeSpanLength];
+
+            var milliseconds = DInt.ToArray(bytes);
+            for (var i = 0; i < milliseconds.Length; i++)
+                result[i] = System.TimeSpan.FromMilliseconds(milliseconds[i]);
+
+            return result;
+        }
+
+        /// <summary>
+        /// Converts a <see cref="T:System.DateTime"/> value to a byte array.
+        /// </summary>
+        /// <param name="timeSpan">The DateTime value to convert.</param>
+        /// <returns>A byte array containing the S7 date time representation of <paramref name="timeSpan"/>.</returns>
+        /// <exception cref="ArgumentOutOfRangeException">Thrown when the value of
+        ///   <paramref name="timeSpan"/> is before <see cref="P:SpecMinimumDateTime"/>
+        ///   or after <see cref="P:SpecMaximumDateTime"/>.</exception>
+        public static byte[] ToByteArray(System.TimeSpan timeSpan)
+        {
+            if (timeSpan < SpecMinimumTimeSpan)
+                throw new ArgumentOutOfRangeException(nameof(timeSpan), timeSpan,
+                    $"Time span '{timeSpan}' is before the minimum '{SpecMinimumTimeSpan}' supported in S7 time representation.");
+
+            if (timeSpan > SpecMaximumTimeSpan)
+                throw new ArgumentOutOfRangeException(nameof(timeSpan), timeSpan,
+                    $"Time span '{timeSpan}' is after the maximum '{SpecMaximumTimeSpan}' supported in S7 time representation.");
+
+            return DInt.ToByteArray(Convert.ToInt32(timeSpan.TotalMilliseconds));
+        }
+
+        /// <summary>
+        /// Converts an array of <see cref="T:System.DateTime"/> values to a byte array.
+        /// </summary>
+        /// <param name="timeSpans">The DateTime values to convert.</param>
+        /// <returns>A byte array containing the S7 date time representations of <paramref name="dateTime"/>.</returns>
+        /// <exception cref="ArgumentOutOfRangeException">Thrown when any value of
+        ///   <paramref name="timeSpans"/> is before <see cref="P:SpecMinimumDateTime"/>
+        ///   or after <see cref="P:SpecMaximumDateTime"/>.</exception>
+        public static byte[] ToByteArray(System.TimeSpan[] timeSpans)
+        {
+            var bytes = new List<byte>(timeSpans.Length * 4);
+            foreach (var timeSpan in timeSpans) bytes.AddRange(ToByteArray(timeSpan));
+
+            return bytes.ToArray();
+        }
+    }
+}