asked on
MSComm OCX - buffering
I am reading data (ASCII string ) from the serial port that often gets broekn up. What I mean is this -
The sting has a start and end character to deliminate the entire string -
<sasrwaskdmswriuwriwrwer> where there is a fixed number of charcters.
However, the string often arrives in pieces. There may be <sasrwask that arrives, followed soon
after by the rest (i.e. dmswriuwriwrwer>).
I need to assemble the string back together and then bring it into my app. (VB). I assume I need to keep the parts
in a buffer and then assemble them to make up the proper string.
Can anyone provide me with some hints on how to do this. I have examined the VBTerm sample
but not sure if it can assemble the parts of the string.
Thanks
The sting has a start and end character to deliminate the entire string -
<sasrwaskdmswriuwriwrwer> where there is a fixed number of charcters.
However, the string often arrives in pieces. There may be <sasrwask that arrives, followed soon
after by the rest (i.e. dmswriuwriwrwer>).
I need to assemble the string back together and then bring it into my app. (VB). I assume I need to keep the parts
in a buffer and then assemble them to make up the proper string.
Can anyone provide me with some hints on how to do this. I have examined the VBTerm sample
but not sure if it can assemble the parts of the string.
Thanks
Visual Basic Classic
Last Comment
CleanupPing
ASKER
Thanks, I'll try it and get back to you on the results. Might be a few days before I respond.
Cheers
Cheers
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ASKER
Are you familiar with the VBTerm sample program?
ASKER
OK, I've done some tests using the VBTerm sample and here's what is happening -
I've got one instance of the VBTerm sending out text -
MSComm1.Output = ">R84999805315723040202A03
On the second instance of VBTerm I've got -
In the OnComm sub there is -
Select Case MSComm1.CommEvent
' Event messages.
Case comEvReceive
Dim Buffer As Variant
Buffer = MSComm1.Input
Debug.Print "Receive - " & StrConv(Buffer, vbUnicode)
ShowData txtTerm, (StrConv(Buffer, vbUnicode))
Private Static Sub ShowData(Term As Control, Data As String)
The Data variable ends up broken into parts -
">R849998"
"05315723"
"040202A0"
"308269N1"
"0141581E"
"000198<"
">R849998"
"05315723"
"040202A0"
"308269N1"
"0141581E
For testing I am saving the Data to a text file for analysis and I get the above in the text file. Is there a way to avoid re-assemling the string?
I've got one instance of the VBTerm sending out text -
MSComm1.Output = ">R84999805315723040202A03
On the second instance of VBTerm I've got -
In the OnComm sub there is -
Select Case MSComm1.CommEvent
' Event messages.
Case comEvReceive
Dim Buffer As Variant
Buffer = MSComm1.Input
Debug.Print "Receive - " & StrConv(Buffer, vbUnicode)
ShowData txtTerm, (StrConv(Buffer, vbUnicode))
Private Static Sub ShowData(Term As Control, Data As String)
The Data variable ends up broken into parts -
">R849998"
"05315723"
"040202A0"
"308269N1"
"0141581E"
"000198<"
">R849998"
"05315723"
"040202A0"
"308269N1"
"0141581E
For testing I am saving the Data to a text file for analysis and I get the above in the text file. Is there a way to avoid re-assemling the string?
ASKER
OK, I think I have figured out half my problem.
In the onComm Sub I now have -
Case comEvReceive
Dim thePos1, thePos2 As Integer
Buffer = Buffer & MSComm1.Input 'Buffer is declared on top of Form
thePos1 = InStr(StrConv(Buffer, vbUnicode), ">")
thePos2 = InStr(StrConv(Buffer, vbUnicode), "<")
If thePos1 And thePos2 Then
Debug.Print "Receive - " & StrConv(Buffer, vbUnicode)
ShowData txtTerm, (StrConv(Buffer, vbUnicode))
MSComm1.InBufferCount = 0
Buffer = ""
End If
So far this seem to work. Sometimes a part of the string is delayed in arriving at the comm port. Therefore, I'll need a timer as a 'Time Out" timer. If the timer exceeds the thresh hold then throw the buffor away.
In the onComm Sub I now have -
Case comEvReceive
Dim thePos1, thePos2 As Integer
Buffer = Buffer & MSComm1.Input 'Buffer is declared on top of Form
thePos1 = InStr(StrConv(Buffer, vbUnicode), ">")
thePos2 = InStr(StrConv(Buffer, vbUnicode), "<")
If thePos1 And thePos2 Then
Debug.Print "Receive - " & StrConv(Buffer, vbUnicode)
ShowData txtTerm, (StrConv(Buffer, vbUnicode))
MSComm1.InBufferCount = 0
Buffer = ""
End If
So far this seem to work. Sometimes a part of the string is delayed in arriving at the comm port. Therefore, I'll need a timer as a 'Time Out" timer. If the timer exceeds the thresh hold then throw the buffor away.
ASKER
To those who contributed: I sort of figured out my own problem once I was familiar with the VBTerm code, and so far it is working fine.
So what do I do now?I hate to leave questions hanging!
So what do I do now?I hate to leave questions hanging!
ASKER
To those who contributed: I sort of figured out my own problem once I was familiar with the VBTerm code, and so far it is working fine.
So what do I do now?I hate to leave questions hanging!
So what do I do now?I hate to leave questions hanging!
Malek:
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Public Declare Sub Sleep Lib "kernel32" Alias "Sleep" (ByVal dwMilliseconds As Long)
in oncomm of communication control
Private Sub MSComm1_OnComm()
sleep (50)
' here ur code
End Sub
you will get complete data