refactor: Replace DateTime.Length with Plc.DateTimeLength in Plc.Clock

This commit is contained in:
Michael Croes
2023-09-04 22:20:31 +02:00
parent cb24e9a046
commit 4764c997ed
2 changed files with 15 additions and 11 deletions

View File

@@ -16,6 +16,11 @@ partial class Plc
private const int PduErrOffset = 20;
private const int UserDataResultOffset = PduErrOffset + 2;
/// <summary>
/// The length in bytes of DateTime stored in the PLC.
/// </summary>
private const int DateTimeLength = 10;
private static byte[] BuildClockReadRequest()
{
var stream = new MemoryStream();
@@ -30,18 +35,21 @@ partial class Plc
private static DateTime ParseClockReadResponse(byte[] message)
{
const int udLenOffset = UserDataResultOffset + 2;
const int udValueOffset = udLenOffset + 4;
const int udValueOffset = udLenOffset + 2;
const int dateTimeSkip = 2;
AssertPduResult(message);
AssertUserDataResult(message, 0xff);
var len = Word.FromByteArray(message.Skip(udLenOffset).Take(2).ToArray());
if (len != Types.DateTime.Length)
if (len != DateTimeLength)
{
throw new Exception($"Unexpected response length {len}, expected {Types.DateTime.Length}.");
throw new Exception($"Unexpected response length {len}, expected {DateTimeLength}.");
}
return Types.DateTime.FromByteArray(message.Skip(udValueOffset).Take(Types.DateTime.Length).ToArray());
// Skip first 2 bytes from date time value because DateTime.FromByteArray doesn't parse them.
return Types.DateTime.FromByteArray(message.Skip(udValueOffset + dateTimeSkip)
.Take(DateTimeLength - dateTimeSkip).ToArray());
}
private static byte[] BuildClockWriteRequest(DateTime value)
@@ -49,8 +57,9 @@ partial class Plc
var stream = new MemoryStream();
WriteUserDataRequest(stream, SzlFunctionGroupTimers, SzlSubFunctionWriteClock, 14);
stream.Write(new byte[] { 0xff, TransportSizeOctetString, 0x00, Types.DateTime.Length });
stream.Write(new byte[] { 0x00, 0x19 }); // Start of actual DateTime value, DateTime.ToByteArray is broken
stream.Write(new byte[] { 0xff, TransportSizeOctetString, 0x00, DateTimeLength });
// Start of DateTime value, DateTime.ToByteArray only serializes the final 8 bytes
stream.Write(new byte[] { 0x00, 0x19 });
stream.Write(Types.DateTime.ToByteArray(value));
stream.SetLength(stream.Position);

View File

@@ -8,11 +8,6 @@ namespace S7.Net.Types
/// </summary>
public static class DateTime
{
/// <summary>
/// The length in bytes of DateTime stored in the PLC.
/// </summary>
public const int Length = 10;
/// <summary>
/// The minimum <see cref="T:System.DateTime"/> value supported by the specification.
/// </summary>