python-escpos | Fork of python-escpos : Allows * * | Computer Vision library

Please try specifying the GS a command as a parameter in the query_status() method and calling it.

GS a

The interface board of the EPSON printer is modularized and commonly used by many printers.
Interface Board
UB-U

The PID is for that interface board and is the same for any printer that uses it.

For example, for Japanese materials, the PID is the same for TM-m30 and TM-T88VI.
TM-m30 page 86
TM-T88VI page 118

Therefore, VID 0x04B8 and PID 0x0202 can be considered as IDs of USB interface boards of EPSON printers.

If you can get the Manufacturer and Product String Descriptors written in the document, you will be able to determine the printer model.

From reading the docs, it seems to me that you would have to use

Using kivy instead of sys like @inclement suggested was the solution

Not being a Python programmer, I cannot provide any sample code.

But I can give you some other hints:

1. Your assumption, that "in theory, [....] just send correctly formatted data to the IP address + port" is wrong.

   If you send something, you have to "talk IPP" to the CUPS server (yes, via the IP address + port 631). But just sending a file is so much less than talking IPP.

   Else, you could use 'netcat IPaddress port-no < filename' to print to any CUPS queue (which would be a huge security issue).

   So you HAVE to use some IPP-capable library, if you want to integrate your program with IPP/CUPS

2. One alternative could be that you let your program do the "IPP talk to CUPS" by a CLI tool which is capable of doing so.

   Have a look at the ippsample code of the Printer Working Group (PWG) which designed the IPP. That is in "beta" still but already fully usable. All its binaries are command line (CLI) utilities:

   • It provides the ippfind helper tool. If you run it without any parameters, it will print a list of available IPP Services (print servers and/or printer devices) by printing their respective IPP URIs.

   • It provides an ippserver command line, which can start up a fully-fledged, you guessed it, IPP Server exposing any feature you want.

   • Then there is ipptool included as an IPP Client. You could run 'ipptool -f myprintfile -t -v ipp://cupsserver/printers/test_printer print-job.test' to send "myprintfile" to the queue "test_printer" on "cupsserver" (given with example IPP URI ipp://cupsserver/printers/test_printer) and watch it talk IPP to CUPS while it does so.

  See also my ASCIIcast "[TUTORIAL] IPP Sample Software (made with an AppImage)" here. {https://asciinema.org/a/155588 }. Hint: if it plays too fast to follow and understand the screens in time, use the 'pause' button, read at your own speed, then resume playing.

Answering my own question here. So, it turns out, the problem was with python-escpos library. I had to remove the following from the printer.py (python module of that library):

If you are using python-escpos 2.2.0, look at the source and documentation for that version.

There is no ln or is_online function in that version.

Change the mode from 664 to 666 in your udev rule and it will work.