Brother MFC-2750DW isn't scanning duplex.

[heinrichat]

Hi!

Bought completely new. Everything works flawlessly except duplex scanning. The printer has duplex scanning capability. Using on Debian 10.

Latest firmware version installed ZA 1.12 ROM version is called ZA2211160228:DB30

$ scanimage -V
scanimage (sane-backends) 1.0.31-debian; backend version 1.0.31

$ apt list installed sane-airscan
Listing... Done
sane-airscan/oldstable,now 0.99.24-1 amd64 [installed]

$ airscan-discover
[devices]
  Brother MFC-L2750DW series = http://192.168.1.92:80/eSCL/, eSCL
  Brother MFC-L2750DW series = http://192.168.1.92:80/WebServices/ScannerService, WSD
  Brother MFC-L2750DW series = http://[FE80::12B1:DFFF:FED3:45F7%252]:80/WebServices/ScannerService, WSD
  Brother MFC-L2750DW series = http://[FE80::12B1:DFFF:FED3:45F7%253]:80/WebServices/ScannerService, WSD

$ scanimage -A
scanimage: rounded value of br-x from 215.9 to 215.9
scanimage: rounded value of br-y from 296.926 to 296.926

All options specific to device `escl:http://192.168.1.92:80':
  Scan mode:
    --mode Lineart|Gray|Color [Color]
        Selects the scan mode (e.g., lineart, monochrome, or color).
    --resolution 100|200|300|600dpi [100]
        Sets the resolution of the scanned image.
    --preview[=(yes|no)] [no]
        Request a preview-quality scan.
    --preview-in-gray[=(yes|no)] [no]
        Request that all previews are done in monochrome mode.  On a
        three-pass scanner this cuts down the number of passes to one and on a
        one-pass scanner, it reduces the memory requirements and scan-time of
        the preview.
  Geometry:
    -l 0..210.481mm [0]
        Top-left x position of scan area.
    -t 0..291.507mm [0]
        Top-left y position of scan area.
    -x 5.41866..215.9mm [215.9]
        Width of scan-area.
    -y 5.41866..296.926mm [296.926]
        Height of scan-area.
    --source Flatbed|ADF|ADF Duplex [Flatbed]
        Selects the scan source (such as a document-feeder).

After placing two sheets of paper into the DADF... printer tells me "ADF ready" on the mini color display and I issue following command...

$ scanimage -b --source "ADF Duplex"
scanimage: rounded value of br-x from 215.9 to 215.9
scanimage: rounded value of br-y from 355.6 to 355.6
Scanning infinity pages, incrementing by 1, numbering from 1
Scanning page 1
Scanned page 1. (scanner status = 5)
Scanning page 2
scanimage: sane_start: Invalid argument
Batch terminated, 1 page scanned

It creates only one file containing the "frontside" of the first page.

Here is the debug output. I had to use pastebin, because github comment can have max 65536 chars... M$ apperantly is running low on disk space and has to skimp on storage :/

And here is the debug trace log.

Thank you for your help.

[heinrichat]

Maybe duplicate of #225. It's even the same printer.

It doesn't matter if I do --source="ADF" or --source="ADF Duplex" ... I always get only one file.

Generally it would be great if there would be a community spreadsheet with all tested printers with tested firmware version, sane-airscan version and all the confirmed features working (or not).

[heinrichat]

When I place two sheets of paper into the ADF and issue the following command... (The backslash is for ignoring a bash alias)

\scanimage -b --batch-prompt --source="ADF Duplex"

I get this output:

$ \scanimage -b --batch-prompt --source "ADF Duplex"
Output format is not set, using pnm as a default.
scanimage: rounded value of br-x from 215.9 to 215.9
scanimage: rounded value of br-y from 355.6 to 355.6
Scanning infinity pages, incrementing by 1, numbering from 1
Place document no. 1 on the scanner.
Press <RETURN> to continue.
Press Ctrl + D to terminate.

Scanning page 1
Scanned page 1. (scanner status = 5)
Place document no. 2 on the scanner.
Press <RETURN> to continue.
Press Ctrl + D to terminate.

Scanning page 2
scanimage: sane_start: Invalid argument
Batch terminated, 1 page scanned

I press return key once. The ADF starts scanning all the paper until the ADF is empty. Then it prompts me to again press return to scan the next page, but obviously the ADF is already empty (duh!) and it exits.

Maybe this can help.

[alexpevzner]

Hi @heinrichat,

I need a protocol trace. Standard log is not detailed enough to troubleshoot issues like this.

Please, uncomment the following lines in the /etc/sane.d/airscan.conf file:

[debug]
trace = ~/airscan/trace

Protocol traces will be collected in the ~/airscan/trace directory (it will be created automatically). For now, .tar files are not needed, I need only .log files.

[heinrichat]

I've already done that.

And here is the debug trace log.

[alexpevzner]

Looks like you have both sane-airscan and sane-escl installed, and actually scan with sane-escl.

It may happen because you don't explicitly specify the device when invoking the scanimage command and the first device in the list appears to be from the sane-escl driver.

I suggest you to try to comment out the escl keyword in the /etc/sane.d/dll.conf file and retest.

[heinrichat]

Dude... it works!

Finally... after Canon, Ricoh, Kyocera I found Brother which just works. Thank you!!

[alexpevzner]

Glad to hear! :)