How can I access ink levels of printers programmatically?

Question

Okay, this is a Windows specific question.

I need to be able to access the ink levels of a printer connected to a computer. Possibly direct connection, or a network conn

Answer 1

I have an SNMP-capable HP 8600 pro N911a around to do some digging, so the following commands may help you a bit. Beware that this particular model has some firmware problems, you can't query "magenta" with snmpget, but you see a value with snmpwalk (which does some kind of recursive drill-down).

OLD: You can query the names and sequence of values, but I couldn't find the "max value" to calculate a clean percentage so far ;(. I'm guessing so far the values are relative to 255, so dividing by 2.55 yields a percentage.

Update: Marcelo's hint was great! From Registers .8.* you can read the max level per cartridge, and I was totally wrong assuming the max value can only be an 8-bit value. I have updated the sample script to read the max values and calculate c

There is also some discussion over there at Cacti forums. One answer confirms that the ink levels are measured as percent (value 15 is "percent" in an enumeration):

# snmpwalk -v1 -c public 192.168.100.173 1.3.6.1.2.1.43.11.1.1.7                 
SNMPv2-SMI::mib-2.43.11.1.1.7.0.1 = INTEGER: 15
SNMPv2-SMI::mib-2.43.11.1.1.7.0.2 = INTEGER: 15
SNMPv2-SMI::mib-2.43.11.1.1.7.0.3 = INTEGER: 15
SNMPv2-SMI::mib-2.43.11.1.1.7.0.4 = INTEGER: 15

You need to install the net-snmp package. If you're not on Linux you might need some digging for SNMP command line tools for your preferred OS.

# snmpwalk -v1 -c public 192.168.100.173 1.3.6.1.2.1.43.11.1.1.6.0
SNMPv2-SMI::mib-2.43.11.1.1.6.0.1 = STRING: "black ink"
SNMPv2-SMI::mib-2.43.11.1.1.6.0.2 = STRING: "yellow ink"
SNMPv2-SMI::mib-2.43.11.1.1.6.0.3 = STRING: "cyan ink"
SNMPv2-SMI::mib-2.43.11.1.1.6.0.4 = STRING: "magenta ink"

# snmpwalk -v1 -c public 192.168.100.173 1.3.6.1.2.1.43.11.1.1.9.0
SNMPv2-SMI::mib-2.43.11.1.1.9.0.1 = INTEGER: 231
SNMPv2-SMI::mib-2.43.11.1.1.9.0.2 = INTEGER: 94
SNMPv2-SMI::mib-2.43.11.1.1.9.0.3 = INTEGER: 210
SNMPv2-SMI::mib-2.43.11.1.1.9.0.4 = INTEGER: 174

# snmpwalk -v1 -c praxis 192.168.100.173 1.3.6.1.2.1.43.11.1.1.8.0
SNMPv2-SMI::mib-2.43.11.1.1.8.0.1 = INTEGER: 674
SNMPv2-SMI::mib-2.43.11.1.1.8.0.2 = INTEGER: 240
SNMPv2-SMI::mib-2.43.11.1.1.8.0.3 = INTEGER: 226
SNMPv2-SMI::mib-2.43.11.1.1.8.0.4 = INTEGER: 241

On my Linux box I use the following script to do some pretty-printing:

#!/bin/sh

PATH=/opt/bin${PATH:+:$PATH}

# get current ink levels
eval $(snmpwalk -v1 -c praxis 192.168.100.173 1.3.6.1.2.1.43.11.1.1.6.0 |
perl -ne 'print "c[$1]=$2\n" if(m!SNMPv2-SMI::mib-2.43.11.1.1.6.0.(\d) = STRING:\s+"(\w+) ink"!i);')

# get max ink level per cartridge
eval $(snmpwalk -v1 -c praxis 192.168.100.173 1.3.6.1.2.1.43.11.1.1.8.0 |
perl -ne 'print "max[$1]=$2\n" if(m!SNMPv2-SMI::mib-2.43.11.1.1.8.0.(\d) = INTEGER:\s+(\d+)!i);')

snmpwalk -v1 -c praxis 192.168.100.173 1.3.6.1.2.1.43.11.1.1.9.0 |
perl -ne '
    my @c=("","'${c[1]}'","'${c[2]}'","'${c[3]}'","'${c[4]}'");
    my @max=("","'${max[1]}'","'${max[2]}'","'${max[3]}'","'${max[4]}'");
    printf"# $c[$1]=$2 (%.0f)\n",$2/$max[$1]*100
        if(m!SNMPv2-SMI::mib-2.43.11.1.1.9.0.(\d) = INTEGER:\s+(\d+)!i);'