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

Okay, this is a OS agnostic answer... :-)

If the printer isn't a very cheapo model, it will have built-in support for SNMP (Simple Network Management Protocol). SNMP queries can return current values from the network devices stored in their MIBs (Management Information Bases).

For printers there's a standard defined called Printer MIB. The Printer MIB defines standard names and tree locations (OIDs == Object Identifiers in ASN.1 notation) for prtMarkerSuppliesLevel which in the case of ink marking printers map to ink levels.

Be aware that SNMP also allows private extensions to the standard MIBs. Most printer vendors do hide many additional pieces of information in their "private MIBs", though the standard info should always be available through the queries of the Printer MIB OIDs.

Practically every programming language has standard libraries which can help you to make specific SNMP queries from your own application.

One such implementation is Open Source, called Net-SNMP, which also comes with a few powerfull commandline tools to run SNMP queries.

I think the OID to query all levels for all inks is .1.3.6.1.2.1.43.11.1.1.9 (this webpage confirms my believe) but I cannot verify that right now, because I don't have a printer around in my LAN at the moment. So Net-SNMP's snmpget command to query ink levels should be something like:

snmpget                       \
  -c public                   \
   192.168.222.111            \
   ".1.3.6.1.2.1.43.11.1.1.9"

where public is the standard community string and 192.168.222.111 your printer's IP address.