>I have a device on a usb port which I can successfully write directly to. However, I am experiencing difficulties reading directly from the port.
>
>Everything below works (the commands go to the device) until it gets to the readfile portion. The device is sending data back but the readfile() is not capturing it. Any ideas?
>
>
>*--lc_DeviceName is returned from SetupDiGetDeviceInterfaceDetail
>lh_Device = CreateFile(lc_DeviceName, ;
> GENERIC_READ + GENERIC_WRITE ,;
> FILE_SHARE_READ + FILE_SHARE_WRITE, 0, OPEN_ALWAYS,;
> FILE_ATTRIBUTE_NORMAL + FILE_FLAG_SEQUENTIAL_SCAN, 0)
>
>IF (lh_Device != INVALID_HANDLE_VALUE)
>
> lw_Buffer = SPACE( MAX_PATH )
> lcSendValue = [! U1 MCR 80 T1 T2] + CHR(10) + CHR(13)
> lnWritten = 0
>
> IF WriteFile(lh_Device, lcSendValue, LEN(lcSendValue),@lnWritten,0) <> 0
>
> *!!!! Success - the device responds to the command sent
> *!!!! Now capture the data returning from the device (the response)
>
> lcReadBuffer = REPLICATE(" ",MAX_PATH)
> lnBytesReturned = 0
> lnCounter2 = 0
>
> *--Latest attempt is to loop through a read for awhile
> DO WHILE lnBytesReturned == 0
> lncounter2 = lncounter2 + 1
> IF ReadFile(lh_Device, @lcReadBuffer, LEN(lcReadBuffer), @lnBytesReturned, 0) <> 0
> lncounter = 0
> DO WHILE lncounter < 50
> lncounter = lncounter + 1
> DOEVENTS
> IF !EMPTY(MakeANSI(lcReadBuffer))
> ? lcReadBuffer
> ? MakeANSI(lcReadBuffer)
> ENDIF
> ENDDO
> * ADD GetQueuedCompletionStatus()
> ENDIF
> IF lncounter2 = 100
> EXIT
> ENDIF
> ENDDO
> ENDIF
> CloseHandle( lh_Device )
>ENDIF
>
Sorry Tracy - I'm way behind you in this area but interested in reading data from USB scanners - if I get anywhere I'll let you know
Colin
Specialist in Advertising, Marketing, especially Direct Marketing
I run courses in Business Management and Marketing