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Questions[cups-lpd](ubuntu)

Martin Hope
Joe Molnar
Asked: 2020-05-24 18:34:49 +0800 CST
  • 2

Upon rebooting, I get dialog box 

Authentication Required

Authentication is required to start 'cups.service'.

I can type in the password and click Authenticate, but then nothing happens. I can't see under the box. I can't move the box, can't cancel the dialog.

But, I can click on where I know the underneath icon to be and that click is accepted and the program in question runs.

Thank you in advance ...

I have recently done a clean install of 20.04. enter image description here

printing .desktop desktop-icons cups-lpd ubuntu-gnome
Martin Hope
unknowndomain
Asked: 2020-01-31 09:29:24 +0800 CST
  • 3

I have developed a piece of software for asset management that prints it's own barcode labels, this software works perfectly on on macOS with CUPS but I want to use an Intel NUC with Ubuntu for production purposes.

The printer I am using is a Brother P-Touch label printer, they all broadly are similar the specific models I am interested in are the PT-P900W (Wi-Fi + USB) and the PT-P950NW (Ethernet, Wi-Fi + USB).

Printing with my software works fine in macOS, it generates the PDF and uses IPP to send it to the macOS CUPS server, and then onward using LPD to the printer. However this same setup on Ubuntu works but the print quality is awful.

I've tried working with Brother and they're not able to resolve it as they say the software should be able to have a print quality setting. I agree with that view point so I did the work to use IPP to get all the printer settings and discover what print features were supported and try changing them, I noticed on macOS the default resolution is 360dpi where as on Ubuntu it was 300dpi, so I tried changing this, but the print comes out the same.

I have read the PPD file and it has a commented out section for resolution, which if uncommented causes the printer to stop working.

*%==== Resolution Features =================================
*%OpenUI *Resolution/Resolution: PickOne
*%OrderDependency: 14 AnySetup *Resolution
*%DefaultResolution: Standard
*%Resolution    Standard/360 X 360 dpi (Standard):      "          "

It feels likely this is a driver issue but I cannot figure out how to fix the PPD to enable setting the resolution and I am unclear if the PPD is the definition of how to talk to the printer, or just the GUI options as there seems to be no code in there about how to talk to the printer.

Tl;dr:

  1. I am printing from Ubuntu/CUPS to a Brother PT-P950NW and having issues with poor quality output.
  2. I have working and tested software that uses IPP to CUPS to send it a vector PDF file - Quality shouldn't be an issue it works on macOS.
  3. There is a notable difference in features implemented between the macOS PPD and the Linux PPD, including that the resolution setting which is at 300dpi rather than 360dpi for Linux/macOS.

Can someone help me to fix this printer quality issue?

drivers printing display-resolution brother cups-lpd
Martin Hope
burnedfaceless
Asked: 2019-03-24 15:29:25 +0800 CST
  • 29

I am running Ubuntu 18.04.2 Desktop on my laptop.

I have installed CUPS to a Raspberry Pi running Raspbian. My Mac will consistently print to this printer without any problems.

From Ubuntu Desktop I am only able to print to the printer ~1 minute after a reboot of Ubuntu Desktop. After that time documents will not print.

When I visit ‘localhost:631’ from Ubuntu Desktop the status is listed as ‘Idle - “No suitable Destination Host found by cups-browsed”’ (see attached).

Images can be seen here https://imgur.com/a/mm4WzMS

printing cups-lpd
Martin Hope
Clovis
Asked: 2019-02-02 06:24:10 +0800 CST
  • 7

I just upgraded to 18.04LTS, I print over a network printer using CUPS. Since my upgrade, when printing N copies of a PDF (through Okular or Evince), I get N^2 copies printed. However, when I use a direct call to CUPS: lp -d my-printer -n 5 example.pdf I get the right number of copies (5 in this example). I guess the applications are simply calling N times N copies.

Moreover, the printing options (stapling, etc.) are absent from the Options panel, and I need to tune them through the general Setting panel of Ubuntu.

What is the communication channel between applications and CUPS? How can I configure my printing "pipeline" so that it directly calls something like the lp cmmand?

Thanks for your help!

Note: this is not the same situation as https://unix.stackexchange.com/questions/265538/cups-prints-n%C2%B2-as-many-copies-as-i-want since in their case, the lp command was giving also the wrong number of copies.

printing cups-lpd
Martin Hope
lepe
Asked: 2018-10-15 07:44:19 +0800 CST
  • 3

Installed WPS Office in two computers (Ubuntu 18.04 x64), one through snap and one though apt. I have a printer connected to another server, which is published using cups, and works fine in other applications (like libreoffice, pdf viewer, etc).

In both the clients, it shows the error: "WPS Office has not found any installed printers" when clicking the print button or from the menu.

I couldn't find any solution so far. Any way to debug this issue or to solve it?

printing cups-lpd wps-office