I try to read from a virtual port using windows API method ReadFile (http://msdn.microsoft.com/library/default.asp?url=/library/en-us/fileio/fs/readfile.asp).
This method always return 0 byte received.
I successfully open the com port with : CreateFileA("COM8", 80000000h + 40000000H, 0, 0, 3, 0, 0)
I successfully call ReadFile from the port with : ReadFile(CMD:HandlePortComCommande, CMD:carac, 1, NbRead, 0), but nbRead always return with a value of zero.
Code works with other virtual port supplier and works with real com port.
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Andrew FabulaTech Forum Moderator
Moderator FabulaTech Forum Senior Member
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Re: Problem using virtual port with windows API Reply #1 on: Dec 5th, 2006, 1:33am
Could you please clarify, what our product do you use? As I understand you use Virtual Serial Port Control. You created virtual COM port and try to read from that COM port. Is it so?
I'm using Virtual Serial Port Kit version 4.8.3, licensed. I create COM7 and COM8, associated together. My application intend to receive data on COM8 (it can be another com port too).
To test, I send data to com7 with hyperterminal, but my application always have a result of 0 byte read anytime. There is no error returned by called functions.
When I connect togother 2 physical com port with a null modem cable, com3 and com4 for example, it's working fine.
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Andrew FabulaTech Forum Moderator
Moderator FabulaTech Forum Senior Member
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Re: Problem using virtual port with windows API Reply #3 on: Dec 5th, 2006, 6:16am
So, I installed new version. Same problem. I tried something else : I change flow control from hardware to none. Working fine with this and with xon/xoff.
I don't know if I could have the same problem with older version.
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Posts: 427