If you use hyperterminal on COM1 (with nothing connected, except a hardwired loop-back from Tx to Rx), with flow control NOT set to "none", you get a similar effect to what i was expertiencing earlier - you seem to 'send' two bytes - there is then a long delay, before the next byte is sent. I'm using HyperTerminal Private Edition, Ver 6.3, by Hilgraeve (Build Date Jun 13, 2001).
Hyperterminal private edition ver 6.3 serial#
I don't know a lot about VB : do you know how if the Serial program you provide use a FULL asynchronous transfer (with a thread)?įor your info i'm using Windows XP Professional, Version 2002, Service Pack 2. I was also disapointed to notice that both program don't work in the same way : who do the mistake ? Is it Microsoft or both programmers(hardware&software)? That is what my program use and all characters are displayed correctly whereas Hyperterminal doesn't show all of them (or badly). Compared with some other sources that act as Hyperterminal, I think the matter comes from how the program process received datas.Įxplanation : When I have a look at MSDN site, I saw that the best and more flexible solution to make a serial communication was to use Asynchronous with a Read Thread. In fact, I had already found that Hyperterminal doesn't work as other Serial programme but as WH Tan says, I don't know anymore how Hyperterminal works.įor my last project, I used Serial program which I attached here and C++ sources are available. For the time being it seems like no way to reveal the protocol/API used by HyperTerminal (anyone know? please), but I think we can try to do something using VB or VC++, for example, to simulate the "one byte at time", just to understand that before we make any conclusion.Īlso I would like to hear from others if you know more about this matter. It would be interesting to see the differences among those programs/languages. Perhaps you can do a simple test with VB to send "12345" and see what will happen? So I think "one byte at a time" might be a very different thing on VB COM communication. But in a true COM communication, no such thing as exchange of buffer ownership takes place. What we said earlier in "one byte at a time" means "only one byte is transferred in every exchange of ownership to the USB RAM buffer". Just a point, "one byte at a time" seems to be very confusing between the CDC framework and normal COM communication! CDC framework can be considered as a virtual COM port. I know little about the combination of VB & COM communication.
I will continue this discussions and at the same time do some researches. At some stage when I have completed the half-done CDCRxService, I switched back to HyperTerminal and it is actually acting differently and I didn’t notice that, until I was here. Just for the easiness of debugging and researching of USB CDC framework, since I could hack it all the way I wanted. On the first day when I worked with CDC framework, I decided to get something lightly and transparently, hence I have chosen Ramon little program as the testing tool.
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