Hi Rolf, If the scanner is stopping scanning on a paper-end detector in the ADF (which I suspect it is, although I can't be sure), then it might stop at any arbitrary point even in preview mode. I only get the underrun warning when requesting a preview from the ADF. It could be as you say and the scanner is designed to scan a maximum? of 11" from the ADF.
I will try your change and see what happens, though and I will try the ADF with shorter paper to see what happens. I suspect that what sane gets is arbitrarily determined by the physical length of the paper. I did try the buttons on the scanner. When in "remote" mode for computer scanning, none of the buttons seem to cause a USB interrupt. They all "double beep" which indicates that press is invalid. I'm not sure which buttons would be expected to work in this context. Here is a good picture of the panel: http://bimg2.mlstatic.com/impresora-multifuncional-laser-canon-image-class-mf4770n_MLV-F-4579386679_072013.jpg If you have a chance, could you have a look and let me know which buttons are customarily used? There are no Colour/Grey/Scan buttons as such. The OK buttom might have served this purpose, but it is inactive in scan mode. There are only two which might seem to fit this bill on the far right hand side: "Scan>PC1" and "Scan>PC2" which I think is intended for network scanning, a setup that I have not tried. I will let you know tonight. Cheers and thanks again for your help, Ralph >________________________________ > From: Rolf Bensch <rolf at bensch-online.de> >To: littlesincanada <littlesincanada at yahoo.co.uk> >Cc: sane-devel at lists.alioth.debian.org >Sent: Friday, September 20, 2013 7:47:02 AM >Subject: Re: [sane-devel] New scanner Canon MF4770N Multi function > > >Hi Ralph, > >Am 20.09.2013 06:34, schrieb littlesincanada: >> Hi Rolf, >> OK, diff included for pixma-imageclass.c to git unstable. >> >> I figured out the issue with the underrun: when the printer is scanning >> with the ADF for Preview (full area scan), it auto detects the end of >> paper and terminates the scan earlier than the sane driver is expecting. >> It sees the end of the paper and knows to stop at that point (nothing >> left to scan). >> > >Here the backend expects maximum paper length if you don't request a >smaller format from scanimage or xsane. The scanner stops scanning when >the paper went through the document feeder. > >> It cannot do this when scanning from the platen since it doesn't know >> where the end of the page is. Therefore, I don't get the warning when >> Previewing from the platen. >> > >Sure, the scanner expects 11.7" paper length, but your scanner supports >only 11". Please replace the device define line with this one: > >DEV ("Canon imageCLASS MF4770n", "MF4770", MF4770_PID, 600, 640, 825, >PIXMA_CAP_ADF), > >This should fix this issue. Please report if this is successful. Then >I'll commit your patch to git. > >If you don't want to scan large documents above 11" on the document >feeder, I'll patch this later. > >> I couldn't really get any response from the buttons. My time with the >> printer is running out (I have to ship it to my daughter in Uni) so I'm >> going to have to call it a do at that. >> > >You can check button support with scanimage. Please follow these items >for debugging: > >(1) Connect your scanner to the usb bus. >(2) 'export SANE_DEBUG_PIXMA=11' on the console. >(3) Press any button. >(4) 'scanimage -A' on the console. > >The response from scanimage should contain these lines: > >? Buttons: >? ? --button-update >? ? ? ? Update button state >[pixma] INTR T=1.655 len=32 >[pixma]? 00000000:00 10 00 00 00 00 00 00? 00 00 00 00 00 00 00 00 >[pixma]? 00000010:00 00 00 00 00 00 00 00? 00 00 00 00 00 00 00 00 >[pixma] >? ? --button-1 <int> [1] [read-only] >? ? ? ? Button 1 >? ? --button-2 <int> [0] [read-only] >? ? ? ? Button 2 >? ? --original <int> [0] [read-only] >? ? ? ? Type of original to scan >? ? --target <int> [1] [read-only] >? ? ? ? Target operation type >? ? --scan-resolution <int> [0] [read-only] >? ? ? ? Scan resolution > >The [pixma] lines are from my scanner which is different from yours. > >(5) repeat from (3) for all other buttons. > >Please send me the [pixma] responses for all buttons. Then I can create >a patch for this. > >If you won't get [pixma] debug lines SANE doesn't support the buttons >from your scanner. > >Cheers, >Rolf > > > -------------- next part -------------- An HTML attachment was scrubbed... URL: <http://lists.alioth.debian.org/pipermail/sane-devel/attachments/20130920/f3049ff9/attachment-0001.html>
