How can i resolve hanging my N+ when i want to sync my Netduino with a time server.
Function call:
Utility.SetLocalTime(NTPTime("time-a.nist.gov"))
"time-a.nist.gov" : ntp ok, time,daytime busy, not recommended
He will sometimes hang when receive :
s.Receive(ntpData)
I can choose out of many servers but that is for now not the point.
http://tf.nist.gov/tf-cgi/servers.cgi
How to resolve?
Thanks in advance, Ellen
Private Shared Function NTPTime(ByVal TimeServer As [String]) As DateTime
Dim ep As New IPEndPoint(Dns.GetHostEntry(TimeServer).AddressList(0), 123)
Dim s As New Socket(AddressFamily.InterNetwork, SocketType.Dgram, ProtocolType.Udp)
Dim ntpData As Byte() = New Byte(47) {}
Array.Clear(ntpData, 0, 48)
ntpData(0) = &H1B
s.SendTimeout = 5000
s.SendTo(ntpData, ep)
s.Receive(ntpData) 'with debugging, HERE he will stop.'
Dim offsetTransmitTime As Byte = 40
Dim intpart As Long = 0
Dim fractpart As Long = 0
For i As Integer = 0 To 3
intpart = (intpart << 8) Or ntpData(offsetTransmitTime + i)
Next
For i As Integer = 4 To 7
fractpart = (fractpart << 8) Or ntpData(offsetTransmitTime + i)
Next
Dim milliseconds As Long = CLng(intpart * 1000 + (fractpart * 1000) / &H100000000L)
s.Close()
Dim timeSpan__1 As TimeSpan = TimeSpan.FromTicks(CLng(milliseconds) * TimeSpan.TicksPerMillisecond)
Dim dT As New DateTime(1900, 1, 1)
dT += timeSpan__1
'daylight saving'
If dT.Month < 3 OrElse dT.Month > 10 Then
Return dT.AddHours(1)
End If
If dT.Month > 3 AndAlso dT.Month < 10 Then
Return dT.AddHours(2)
End If
If dT.Month = 3 Then
' in march'
If (dT.Day - CInt(dT.DayOfWeek)) < 25 Then
Return dT.AddHours(1)
End If
If (CInt(dT.DayOfWeek) = 0) AndAlso (dT.Hour < 2) Then
Return dT.AddHours(1)
End If
Return dT.AddHours(2)
End If
' in october'
If (dT.Day - CInt(dT.DayOfWeek)) < 25 Then
Return dT.AddHours(2)
End If
If (CInt(dT.DayOfWeek) = 0) AndAlso (dT.Hour < 2) Then
Return dT.AddHours(2)
End If
Return dT.AddHours(1)
End Function
