Determining Ink Level

Perhaps the most basic function performed by escputil is that of determining the amount of ink remaining in the printer. To do this, the user must know the name of the raw printer device. This is usually /dev/lp0 for a printer connected to the parallel port, or /dev/usb/lp0 for a printer connected to the USB.

If there are multiple printers connected, one of them may be referenced as /dev/lp1 or perhaps /dev/usb/lp1. In the event of uncertainty, and if CUPS is in use, view the following URL with a web browser. At that URL, look for a line which reads "Device URI". The author's USB printer is listed as "Device URI: usb:/dev/usb/lp0".

For this example, assume that the raw printer device is a USB printer specified as /dev/usb/lp0. To get the ink level for this printer, issue this command and notice the output.

  
# escputil -r /dev/usb/lp0 -i

Escputil version 4.3.0, Copyright (C) 2000-2001 Robert Krawitz
Escputil comes with ABSOLUTELY NO WARRANTY; for details type 
'escputil -l'
This is free software, and you are welcome to redistribute it 
under certain conditions; type 'escputil -l' for details. 

           Ink color    Percent remaining
               Black     18
                Cyan     71
             Magenta     70
              Yellow     67
          Light Cyan     71
       Light Magenta     70
    
  

The user would substitute their own raw printer device for the one shown in the example after the "-r" switch. Notice that the printout shows the percent of ink remaining for each color of the author's Epson Stylus Photo 870. When the ink levels get too low, print quality will suffer. In the author's personal experience, ink levels approaching 10% begin to cause print quality degredation, but this will vary depending on the precise printer model.

Error During Ink Level Determination

What? The example above did not work? An error message was printed? What does it mean? There are several possibilities, depending on the specific error message. If the error message is "Invalid argument" (see following example), the problem is that the kernel is not configured with the CONFIG_PRINTER_READBACK option enabled.

# escputil -r /dev/lp0 -i Escputil version 4.3.0, Copyright (C) 2000-2001 Robert Krawitz Escputil comes with ABSOLUTELY NO WARRANTY; for details type 'escputil -l' This is free software, and you are welcome to redistribute it under certain conditions; type 'escputil -l' for details. Cannot read from /dev/lp0: Invalid argument

Another possibile cause for error is that the raw printer device does not have both read and write permission for the user attempting to access the device. In this case, the error message will read "Permission denied". A final possibility is that the raw printer device specified is incorrect, in which case the error message will read "No such device".

Nozzle Check

On an inkjet printer, there are several small holes on the bottom of each ink cartridge through which the ink must flow smoothly in order to create high quality images on paper. If these holes become clogged, the printed image will show small gaps where there should have been ink. One can easily test for the existence of this condition by running a nozzle check. One need not be the root user to issue this command. Note that as shown, the command will print a nozzle test pattern on the default printer. If there are multiple printers present, the desired printer must be specified with an additional "-P printer_name" switch, where "printer_name" is the name of the desired printer.

The printer will print a series of black (and colored) slanted lines on the paper. Observe these lines carefully. If there are gaps or spaces in these lines, then the corresponding nozzle is clogged and the print head must be cleaned. However, if there are no gaps, the nozzles are clean.

  
# escputil -n       
Escputil version 4.3.0, Copyright (C) 2000-2001 Robert Krawitz
Escputil comes with ABSOLUTELY NO WARRANTY; for details type 
'escputil -l'
This is free software, and you are welcome to redistribute it 
under certain conditions; type 'escputil -l' for details. 

Running nozzle check, please ensure paper is in the printer.
    
  

Clean the Print Head

If the printed output is showing gaps where there should have been ink, it is likely that one or more nozzles are clogged and the print head is in need of cleaning. One can verify this by first running a nozzle check and looking for gaps in the printout. To clean the print head, issue the following command. One need not be the root user to issue this command. Note that as shown, the command will clean the print head on the default printer. If there are multiple printers present, the desired printer must be specified with an additional "-P printer_name" switch, where "printer_name" is the name of the desired printer.

  
# escputil -c
Escputil version 4.3.0, Copyright (C) 2000-2001 Robert Krawitz
Escputil comes with ABSOLUTELY NO WARRANTY; for details type 
'escputil -l'
This is free software, and you are welcome to redistribute it 
under certain conditions; type 'escputil -l' for details. 

Cleaning heads...
    
  

Nothing will be printed on the paper. The printer will make some noise as it cleans the print head. Wait until the printer is finished cleaning the print head. Afterwards, execute another nozzle check and insure that the print head is indeed completely clean. Note that the process of cleaning the print head causes ink consumption, so do not clean the print head any more than necessary.

For severely clogged nozzles, one may have to execute two or three cycles of nozzle check followed by a cleaning of the print head. If the printer had gone unused for a long time, the nozzles may be so clogged with dried ink as to be unrecoverable, in which case, the best course of action is to replace the ink cartridge.

Align the Print Head

To insure the highest quality printouts, the print head must be in proper physical alignment. One can check and realign the print head by running this interactive alignment test.

The escputil utility must know the exact printer model in use. One may specify the model on the command line using the "-m" switch, or the utility can detect the printer model if the user passes the "-r" switch and the name of the raw printer device.

Note that an unprivileged user may use this command with the "-m" switch, but that (in general) the root user may only use the "-r" switch (which requires read/write access to the raw printer device). In the case of multiple printers in use, the "-P" switch is required to align the print head on the non-default printer.

Aligning the print head is an interactive process. The utility will print out a set of instructions and ask you for responses. Please read the instructions carefully and follow them precisely. A single sheet of paper will be needed (one can print on both sides to save paper).

The following example illustrates the alignment process when issued by an unprivileged user who specified the printer model on the command line. (To obtain a list of printer models, issue the "escputil -M" command). Of course, your responses will vary and should be substituted for the responses shown in the following example.

  

*** NOTE - 870 is an illustrative example! ***
*** You MUST use the proper printer model! ***
*** Run:  escputil -M for a listing of     ***
*** supported printer models!              ***

linuxpc> escputil -a -m 870
Escputil version 4.3.0, Copyright (C) 2000-2001 Robert Krawitz
Escputil comes with ABSOLUTELY NO WARRANTY; for details type 
'escputil -l'
This is free software, and you are welcome to redistribute it
under certain conditions; type 'escputil -l' for details.

Please read these instructions very carefully before proceeding.

This utility lets you align the print head of your Epson Stylus 
inkjet printer.  Misuse of this utility may cause your print 
quality to degrade and possibly damage your printer.  This utility
has not been reviewed by Seiko Epson for correctness, and is 
offered with no warranty at all.  The entire risk of using this 
utility lies with you.

This utility prints 3 test patterns.  Each pattern looks very
similar.  The patterns consist of a series of pairs of vertical
lines that overlap.  Below each pair of lines is a number between 
1 and 15.

When you inspect the pairs of lines, you should find the pair
of lines that is best in alignment, that is, that best forms 
a single vertical line.  Inspect the pairs very carefully to 
find the best match.  Using a loupe or magnifying glass is 
recommended for the most critical inspection.  It is also 
suggested that you use a good quality paper for the test, so 
that the lines are well-formed and do not spread through the 
paper.  After picking the number matching the best pair, place 
the paper back in the paper input tray before typing it in.

Each pattern is similar, but later patterns use finer dots for
more critical alignment.  You must run all of the passes to 
correctly align your printer.  After running all the alignment
passes, the alignment patterns will be printed once more.  You 
should find that the middle-most pair (#8 out of the 15) is the
best for all patterns. 

After the passes are printed once more, you will be offered the
choices of (s)aving the result in the printer, (r)epeating the
process, or (q)uitting without saving.  Quitting will not restore
the previous settings, but powering the printer off and back 
on will.  If you quit, you must repeat the entire process if 
you wish to later save the results.  It is essential that you 
not turn your printer off during this procedure.

This procedure assumes that your printer is an Epson Stylus Photo
870.  If this is not your printer model, please type control-C now
and choose your actual printer model.

Please place a sheet of paper in your printer to begin the head
alignment procedure. 
Press enter to continue > 
Please inspect the print, and choose the best pair of lines in 
each pattern.  Type a pair number, '?' for help, or 'r' to repeat
the procedure.
Pass #1> 8
Pass #2> 8
Pass #3> 8
Attempting to set alignment...succeeded.
Please verify that the alignment is correct.  After the alignment
pattern is printed again, please ensure that the best pattern 
for each line is pattern 8.  If it is not, you should repeat the 
process to get the best quality printing. 
Please insert a fresh sheet of paper.
Press enter to continue > 
Please inspect the final output very carefully to ensure that your
printer is in proper alignment. You may now: 
  (s)ave the results in the printer,
  (q)uit without saving the results, or
  (r)epeat the entire process from the beginning.
You will then be asked to confirm your choice.
What do you want to do (s, q, r)?
> s
This will permanently alter the configuration of your printer.
WARNING: this procedure has not been approved by Seiko Epson, 
and it may damage your printer. Proceed? 
Please confirm by typing 's' again that you wish to save the 
settings to your printer: 
> s
About to save settings...succeeded!
Your alignment settings have been saved to the printer.
    
  

The following example shows what will happen if an unprivileged user attempts to align the print head by specifying the raw printer device on the command line.

  
linuxpc> escputil -a -r /dev/usb/lp0
Escputil version 4.2.0, Copyright (C) 2000-2001 Robert Krawitz
Escputil comes with ABSOLUTELY NO WARRANTY; for details type 
'escputil -l'
This is free software, and you are welcome to redistribute it
under certain conditions; type 'escputil -l' for details.

Attempting to detect printer model...
Cannot open /dev/usb/lp0 read/write: Permission denied
    
  

This next example illustrates the results obtained when the root user issues an alignment command while specifying the raw printer device. Note that the output is truncated and only shows the printer detection output.

  
# escputil -a -r /dev/usb/lp0
Escputil version 4.3.0, Copyright (C) 2000-2001 Robert Krawitz
Escputil comes with ABSOLUTELY NO WARRANTY; for details type 
'escputil -l'
This is free software, and you are welcome to redistribute it
under certain conditions; type 'escputil -l' for details.

Attempting to detect printer model...Stylus Photo 870

Please read these instructions very carefully before proceeding.
    
  

Printer Identification

The printer identification command will query the printer for make and model information. This command requires read/write access to the raw printer device (generally limited to the root user). Substitute your own raw printer device in place of the /dev/usb/lp0 shown in the example. The output will vary depending on the precise printer model.

  
# escputil -d -r /dev/usb/lp0
Escputil version 4.3.0, Copyright (C) 2000-2001 Robert Krawitz
Escputil comes with ABSOLUTELY NO WARRANTY; for details type 
'escputil -l'
This is free software, and you are welcome to redistribute it
under certain conditions; type 'escputil -l' for details.

@EJL ID
MFG:EPSON;CMD:ESCPL2,BDC;MDL:Stylus Photo 870;CLS:PRINTER;DES:
EPSON Stylus Photo 870;
    
  

More Information

For more detailed information about the command line switches accepted by the escputil utility, please consult the man page which is supplied with the Gimp-Print software. The user may also issue the "escputil --help" command to get a listing of supported command line switches. The command requires no special privileges to execute.