How long is the Buffer in Serial Communication?

[Marcus Warnqvist]

Hello friends,

I'm using this to read RS232:
Buffer = MSComm1.Input

Is there a way read only to a curtain character? (crLF)

I'm sending request with the MSComm1.Output and clearing the Buffer before every request but the Buffer are not receiving the same amount of data every time.

Sometimes: 123.2 bar
Sometimes: r 123
Sometimes: ar 123.
etc.

I want to make sure that I capture the whole message in the buffer.

Thanks for you help in advance!

Marcus

[lastjedi]

I had the same issue and this is how I worked around it. I'm just taking the data 1 byte at a time until I hit the linefeed. I'm fairly new to vb so there is probably a better way to do it, but it works and it seems fast. I'm using vb5 and the vbterm sample helped me out quite a bit, it's a simple routine.

MSComm1.InputLen = 1
Do While MSComm1.InBufferCount > 0
xbuffer = MSComm1.Input
If Asc(StrConv(xbuffer, vbUnicode)) <> 10 Then
If VarType(buffer) = 0 Then
buffer = StrConv(xbuffer, vbUnicode)
Else
buffer = buffer & StrConv(xbuffer,vbUnicode)
End If
Else
If VarType(buffer) <> 0 Then
Debug.Print "Receive - " & buffer
ShowData txtView, buffer
buffer = ""
End If
End If
Loop