1) This printer is conneted by network cable to my Modem / Router
2) It is done that way so that I can print to it from any device in the house that is logged into the same WiFi netwerk.
3) My Ubuntu 20.04 dekstop is connected to the same Modem / Router - by cable
4) I have no problems PRINTING to it

But, I can't SCAN, the printer doesn't "see" the desktop, nor do I see from the HP setup on the desktop that printer to scan from it.

In setup, it is confirmed the printer is published on the netwrork.
It seems, the desktop is missing some drivers maybe? what?

Must I connect the printer directly to the PC to resolve it, or is there another way?

Thanks
Alex

This command will report printer status and that the hp backend is in use (necessary for hpaio scanner driver)...
Does this detect scanner ok?
This diagnostic tool might also yield useful information...

Hello Ferrari, here are my results

alex@alex-nuc8i7hnk:~$ lpstat -t
scheduler is running
system default destination: HP-Officejet-6700
device for HP-Officejet-6700: hp:/net/Officejet_6700?hostname=HP294D1A.local
device for Officejet_6700_294D1A_: implicitclass://Officejet_6700_294D1A_/
HP-Officejet-6700 accepting requests since Sat 22 Aug 2020 17:30:48
Officejet_6700_294D1A_ accepting requests since Sat 22 Aug 2020 18:59:59
printer HP-Officejet-6700 is idle. enabled since Sat 22 Aug 2020 17:30:48
printer Officejet_6700_294D1A_ is idle. enabled since Sat 22 Aug 2020 18:59:59

alex@alex-nuc8i7hnk:~$ lpstat -t
scheduler is running
system default destination: HP-Officejet-6700
device for HP-Officejet-6700: hp:/net/Officejet_6700?hostname=HP294D1A.local
device for Officejet_6700_294D1A_: implicitclass://Officejet_6700_294D1A_/
HP-Officejet-6700 accepting requests since Sat 22 Aug 2020 17:30:48
Officejet_6700_294D1A_ accepting requests since Sat 22 Aug 2020 18:59:59
printer HP-Officejet-6700 is idle. enabled since Sat 22 Aug 2020 17:30:48
printer Officejet_6700_294D1A_ is idle. enabled since Sat 22 Aug 2020 18:59:59
alex@alex-nuc8i7hnk:~$ hp-scan

HP Linux Imaging and Printing System (ver. 3.20.3)
Scan Utility ver. 2.2

Copyright (c) 2001-18 HP Development Company, LP
This software comes with ABSOLUTELY NO WARRANTY.
This is free software, and you are welcome to distribute it
under certain conditions. See COPYING file for more details.

warning: No destinations specified. Adding 'file' destination by default.
Using device hpaio:/net/Officejet_6700?hostname=HP294D1A.local
Opening connection to device...

Resolution: 300dpi
Mode: gray
Compression: JPEG
Scan area (mm):
Top left (x,y): (0.000000mm, 0.000000mm)
Bottom right (x,y): (215.900009mm, 297.010681mm)
Width: 215.900009mm
Height: 297.010681mm
Destination(s): file
Output file:
warning: File destination enabled with no output file specified.
Setting output format to PNG for greyscale mode.
warning: Defaulting to '/home/alex/hpscan001.png'.

Warming up...


Scanning...
Reading data: [******************************************] 100% 8.5 MB
Read 8.5 MB from scanner.
Closing device.

Outputting to destination 'file':

Done.

The final command produces the following errors. I triead : sudo apt-get install for all of them, it is missing or can't find some of them...

Missing Required Dependencies
-----------------------------
error: 'libcups2' package is missing/incompatible
error: 'libdbus-1-dev' package is missing/incompatible
error: 'libjpeg-dev' package is missing/incompatible
error: 'libcups2-dev' package is missing/incompatible
error: 'cups-bsd' package is missing/incompatible
error: 'cups-client' package is missing/incompatible
error: 'libcupsimage2-dev' package is missing/incompatible
error: 'build-essential' package is missing/incompatible
error: 'libusb-1.0.0-dev' package is missing/incompatible
error: 'libusb-0.1-4' package is missing/incompatible
error: 'libsane-dev' package is missing/incompatible
error: 'libsnmp-dev' package is missing/incompatible
error: 'snmp-mibs-downloader' package is missing/incompatible
error: 'openssl' package is missing/incompatible
error: 'python3-pyqt4' package is missing/incompatible
error: 'gtk2-engines-pixbuf' package is missing/incompatible
error: 'python3-dev' package is missing/incompatible
error: 'libtool' package is missing/incompatible
error: 'libtool-bin' package is missing/incompatible
error: 'build-essential' package is missing/incompatible
error: 'build-essential' package is missing/incompatible

Missing Optional Dependencies
-----------------------------
error: 'gtk2-engines-pixbuf' package is missing/incompatible
error: 'xsane' package is missing/incompatible
error: 'python3-notify2' package is missing/incompatible
error: 'python3-dbus.mainloop.qt' package is missing/incompatible

Total Errors: 18
Total Warnings: 1

What can I do next?

Thak you
Alex

The lpstat output confirmed the expected hp backend. Did the hp-scan utility work ok? It certainly appeared to find the scanner device, and saved the scan to /home/alex/hpscan001.png (based on the output captured).

Yes, the test scanned worked, but when I try to scan, it doesn't.

Any suggestions
Thanks
Alex

Can you try running simple-scan from a terminal like this?
*You may need to install the simple-scan package first.

BTW, I assume the multi-function device returns a ping ok?
You could also try via IP address

OK, all 3 work. The 1st - it brought up a GUI interface - Document scanner and I was able to set preferences

Does this indicate that the machine itself has what it needs?
If so, how can I use it in a more normal way?

Many thanks
Alex

Ok, if simple-scan can launch and connect to the scanner, it appears to be working.
I'm really not sure what you mean here? Were you able to scan or not?

Not sure what you mean here either? Does simple-scan (or hp-scan) allow you to successfully scan a document or not? Remember we're not over your shoulder to see what you're trying to do for ourselves.

OK, from your questions, I found the answer - went to Activities, typed Document scanner and the icon came up. So, I managed to do a scan with it without the need of command line.

How can I create a desktop shortcut to it?

Thanks again
Alex

The terminal is useful from a diagnostic POV. Yes, in general all GUI apps should be able to be launched from a menu and/or desktop icon.

I'm not an Ubuntu user, but the following article suggests the simple-scan application should be accessible from the main menu...

https://techpiezo.com/linux/install-...ntu-20-04-lts/

Create a desktop shortcut...
http://ubuntuhandbook.org/index.php/...-ubuntu-20-04/