>Hi,
>
>>>
>Talking to the identical app. (under development) on another PC using a NULL modem cable.
>
>No Handshaking (per the spec of the app. I will ultimately be talking to).
>At other end (testing) I display count of received and data received. Sending 12 bytes but getting only 8. At that point I have no idea how to get the other 4 to be sent.
>
>I'll check the CTS and DSR but assume they're OK.
>
>RThreshold set to 1, SThreshold set to 0 (tried 1 too, no joy).
>No error checking coded yet. I must add some at this point.
>>>
>
>To clarify: is the data sticking in the Send Buffer or just getting lost in transmission ? (If there's no handshaking it should all get transmitted) If it just doesn't arrive that may indicate a buffer overrun - are you checking for comEventOverrun in the OnComm of the receiving end ?
>
>Are you working in event driven (i.e using OnComm()) or polling mode ?
>
>Few thoughts:
>If you're not using any handshaking then RTS/CTS values aren't going to be relevant.
>Is the data straight ASCII or binary - if binary then the InputMode property may have an effect ?
>If you're using OnComm() and the message is of known length you could try setting the RThreshold accordingly on the receiving end.
>Can you test using HyperTerminal to emulate the other app ?
>

Hi Viv,
I am now monitoring for errors... so far none reported.
I am using event-driven and the mode is set for binary.
The message is NOT of known length. I have RThreshold set to 1 but do not seem to be getting what I'd expect, which I thought would be an OnComm event for every char. received.

I'll look at trying Hyperterminal, though I seem now to be getting what I expect using same app. as both ends. But these times when message is shorter than expected still are a worry and I'm planning to use a timer to detect 'incomplete message received'.

Thanks again for your help
Jim

>HTH,
>VIv