Canon MF750C Series (MF754Cdw) works after enabling it in the device settings

[LuzipherMcLeod]

Just wanting to report a working device that is not yet listed under Compatibility: Canon i-SENSYS MF750C Series

After some headaches I got my new Canon i-SENSYS MF754Cdw working. It needs enabling WSD via the Webinterface of the MFD. To enable WSD scanning, go to "Preferences -> Network Settings -> WSD Settings" and enable "Use WSD Scanning".

If this setting is disabled, xsane does find and offer the scanner for selection, but after selecting it fails instantly displaying "Error during device I/O" (which is not very helpful in my opinion).
The SOAP-Answer in this case is "Service not found" - that could probably translated into a better error message for the user.
This is the log with the setting "Use WSD Scanning" set to "off":

00:00:13.186: Canon MF750C Series: device created
00:00:13.186: Canon MF750C Series: added image decoder: "jpeg"
00:00:13.186: Canon MF750C Series: added image decoder: "tiff"
00:00:13.186: Canon MF750C Series: added image decoder: "png"
00:00:13.186: Canon MF750C Series: added image decoder: "bmp"
00:00:13.186: Canon MF750C Series: DEVICE_STM_OPENED->DEVICE_STM_PROBING
00:00:13.186: Canon MF750C Series: using protocol "WSD"
00:00:13.186: Canon MF750C Series: HTTP POST http://192.168.0.5/active/msu/scan
00:00:13.186: Canon MF750C Series: HTTP using timeout: 5000 ms
00:00:13.186: Canon MF750C Series: HTTP resolving 192.168.0.5 80
00:00:13.186: Canon MF750C Series: HTTP trying 192.168.0.5:80
00:00:13.186: Canon MF750C Series: HTTP fdpoll: {--} -> {-w}
00:00:13.269: Canon MF750C Series: HTTP 995 bytes sent
00:00:13.269: Canon MF750C Series: HTTP done request sending
00:00:13.269: Canon MF750C Series: HTTP fdpoll: {-w} -> {rw}
00:00:13.269: Canon MF750C Series: HTTP fdpoll: {rw} -> {r-}
00:00:13.291: Canon MF750C Series: HTTP 176 bytes received
00:00:13.291: Canon MF750C Series: HTTP POST http://192.168.0.5/active/msu/scan: got response headers (500)
00:00:13.292: Canon MF750C Series: HTTP 426 bytes received
00:00:13.292: Canon MF750C Series: HTTP done response reception
00:00:13.292: Canon MF750C Series: HTTP POST http://192.168.0.5/active/msu/scan: 500 Internal Server Error
==============================
POST http://192.168.0.5/active/msu/scan
Connection: close
Content-Type: application/soap+xml
Cache-Control: no-cache
Pragma: no-cache
User-Agent: WSDAPI
Host: 192.168.0.5
Content-Length: 799

<soap:Envelope xmlns:soap="http://www.w3.org/2003/05/soap-envelope" xmlns:wsa="http://schemas.xmlsoap.org/ws/2004/08/addressing" xmlns:sca="http://schemas.microsoft.com/windows/2006/08/wdp/scan">
  <soap:Header>
    <wsa:MessageID>urn:uuid:a42c2ad9-9e00-f2df-3f54-57925670528a</wsa:MessageID>
    <wsa:To>http://192.168.0.5/active/msu/scan</wsa:To>
    <wsa:ReplyTo>
      <wsa:Address>http://schemas.xmlsoap.org/ws/2004/08/addressing/role/anonymous</wsa:Address>
    </wsa:ReplyTo>
    <wsa:Action>http://schemas.microsoft.com/windows/2006/08/wdp/scan/GetScannerElements</wsa:Action>
  </soap:Header>
  <soap:Body>
    <sca:GetScannerElementsRequest>
      <sca:RequestedElements>
        <sca:Name>sca:ScannerConfiguration</sca:Name>
      </sca:RequestedElements>
    </sca:GetScannerElementsRequest>
  </soap:Body>
</soap:Envelope>

Status: 500 Internal Server Error
Date: Sat, 01 Feb 2025 14:02:50 GMT
Server: CANON HTTP Server
Content-Type: application/soap+xml; charset="utf-8"
Content-Length: 426

<soap:Envelope xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:xsd="http://www.w3.org/2001/XMLSchema" xmlns:soap="http://www.w3.org/2003/05/soap-envelope">
  <soap:Body>
    <soap:Fault>
      <soap:Code>
        <soap:Value>soap:Sender</soap:Value>
      </soap:Code>
      <soap:Reason>
        <soap:Text xml:lang="en">Service Not Found</soap:Text>
      </soap:Reason>
    </soap:Fault>
  </soap:Body>
</soap:Envelope>

00:00:13.292: Canon MF750C Series: HTTP POST http://192.168.0.5/active/msu/scan: Internal Server Error
00:00:13.292: Canon MF750C Series: scanner capabilities query: Internal Server Error
00:00:13.292: Canon MF750C Series: DEVICE_STM_PROBING->DEVICE_STM_PROBING_FAILED
00:00:13.292: Canon MF750C Series: removed from device table
00:00:13.293: Canon MF750C Series: closed protocol "WSD"
00:00:13.293: Canon MF750C Series: device destroyed