diff --git a/S7.Net/Plc.Clock.cs b/S7.Net/Plc.Clock.cs
new file mode 100644
index 0000000..8b2e5be
--- /dev/null
+++ b/S7.Net/Plc.Clock.cs
@@ -0,0 +1,53 @@
+using System;
+using System.IO;
+using System.Linq;
+using S7.Net.Helper;
+using S7.Net.Types;
+using DateTime = System.DateTime;
+
+namespace S7.Net;
+
+partial class Plc
+{
+ private const byte SzlFunctionGroupTimers = 0x07;
+ private const byte SzlSubFunctionReadClock = 0x01;
+
+ private static byte[] BuildClockReadRequest()
+ {
+ var stream = new MemoryStream();
+
+ WriteSzlRequestHeader(stream, SzlFunctionGroupTimers, SzlSubFunctionReadClock, 4);
+ stream.Write(new byte[] { 0x0a, 0x00, 0x00, 0x00 });
+
+ stream.SetLength(stream.Position);
+ return stream.ToArray();
+ }
+
+ private static DateTime ParseClockReadResponse(byte[] message)
+ {
+ const int pduErrOffset = 20;
+ const int dtResultOffset = pduErrOffset + 2;
+ const int dtLenOffset = dtResultOffset + 2;
+ const int dtValueOffset = dtLenOffset + 4;
+
+ var pduErr = Word.FromByteArray(message.Skip(pduErrOffset).Take(2).ToArray());
+ if (pduErr != 0)
+ {
+ throw new Exception($"Response from PLC indicates error 0x{pduErr:X4}.");
+ }
+
+ var dtResult = message[dtResultOffset];
+ if (dtResult != 0xff)
+ {
+ throw new Exception($"Response from PLC indicates error 0x{dtResult:X2}.");
+ }
+
+ var len = Word.FromByteArray(message.Skip(dtLenOffset).Take(2).ToArray());
+ if (len != Types.DateTime.Length)
+ {
+ throw new Exception($"Unexpected response length {len}, expected {Types.DateTime.Length}.");
+ }
+
+ return Types.DateTime.FromByteArray(message.Skip(dtValueOffset).Take(Types.DateTime.Length).ToArray());
+ }
+}
\ No newline at end of file
diff --git a/S7.Net/PlcAsynchronous.cs b/S7.Net/PlcAsynchronous.cs
index 63edcd9..2dcd058 100644
--- a/S7.Net/PlcAsynchronous.cs
+++ b/S7.Net/PlcAsynchronous.cs
@@ -320,7 +320,10 @@ namespace S7.Net
/// A task that represents the asynchronous operation, with it's result set to the current PLC time on completion.
public async Task ReadClockAsync(CancellationToken cancellationToken = default)
{
- throw new NotImplementedException();
+ var request = BuildClockReadRequest();
+ var response = await RequestTsduAsync(request, cancellationToken);
+
+ return ParseClockReadResponse(response);
}
///
diff --git a/S7.Net/PlcSynchronous.cs b/S7.Net/PlcSynchronous.cs
index 50483ad..d953710 100644
--- a/S7.Net/PlcSynchronous.cs
+++ b/S7.Net/PlcSynchronous.cs
@@ -498,7 +498,10 @@ namespace S7.Net
/// The current PLC time.
public System.DateTime ReadClock()
{
- throw new NotImplementedException();
+ var request = BuildClockReadRequest();
+ var response = RequestTsdu(request);
+
+ return ParseClockReadResponse(response);
}
///
diff --git a/S7.Net/Types/DateTime.cs b/S7.Net/Types/DateTime.cs
index a685a21..993ca25 100644
--- a/S7.Net/Types/DateTime.cs
+++ b/S7.Net/Types/DateTime.cs
@@ -8,6 +8,11 @@ namespace S7.Net.Types
///
public static class DateTime
{
+ ///
+ /// The length in bytes of DateTime stored in the PLC.
+ ///
+ public const int Length = 10;
+
///
/// The minimum value supported by the specification.
///