Comment 1 for bug 1817214

In /usr/share/hplip/data/models/models.dat there is a section for each device supported by HPLIP. For example

 [hp_colorlaserjet_mfp_m278-m281]
 [deskjet_3630_series]

The printer URIs for these networked devices would be

 hp:/net/hp_colorlaserjet_mfp_m278-m281?ip=<IP_address>
 hp:/net/deskjet_3630_series?ip=<IP_address>

It can now be deduced that their scanner URIs are definitely

 hpaio:/net/hp_colorlaserjet_mfp_m278-281?ip<IP_address>
 hpaio:netdeskjet_3630_series?ip=<IP_address>

Scanning should always be possible by providing a SANE frontend with a
URI. Like so:

 scanimage -d hpaio:/net/hp_colorlaserjet_mfp_m278-m281?ip=<IP_address>
 xane hpaio:/net/hp_colorlaserjet_mfp_m278-m281?ip=<IP_address>
 simple-scan hpaio:/net/deskjet_3630_series?ip=<IP_address>

************************************************************************
* This provides another way of scanning if LP #1797501 is encountered. *
************************************************************************

Note that it is possible to guarantee almost certainly which other devices will be affected by LP #1797501. For example:

 [hp_laserjet_mfp_m426fdw]

The printer URI is hp:/net/hp_laserjet_mfp_m426fdw?ip=<IP_address>
The scanner URI is hpaio:/net/hp_laserjet_mfp_m426fdw?ip=<IP_address>

The device's _uscan._tcp output would have to have

 ty=hp_hp_laserjet_mfp_m426fdw

to avoid LP #1797501.

--
Brian.