zpl.tools
Host status and queries

~HQ - Host Query

Sends one of ten named printer reports back to the host.

~HQ is the umbrella query command: one mnemonic, and ten reports chosen by a two-letter name. The reports cover:

  • error and warning state;
  • the odometer;
  • printhead life and test results;
  • maintenance thresholds;
  • the serial number;
  • the hardware address;
  • the plug-and-play identification string;
  • USB details.

Each one is a fact about a device, and each one returns over the link, not onto the label.

Syntax

~HQq

Support

Recognised, deliberately skippedparsed: none · state: none · rendered: none

Accepted and skipped, because it configures the printer rather than the label. It cannot change the rendered output, and Labelary skips it too.

Returns odometer, error, serial-number and printhead reports over the printer's link. All of them describe hardware, and none affects a rendered label. The renderer does not parse this command. It reports IGNORED_COMMAND at info severity, which does not reach X-Warnings. Labelary is also silent, so the rendered label is identical in both engines. — not pinned by a test

Labelary renders this command.

Parameters

qQueryrequired · one of a set

Which report to return. Each one describes the printer rather than the label.

Invalid value
not documented, and we have not measured it. The renderer does not parse this command, so no one measured an unrecognized query name. The reference states no default; an omitted query has nothing to select.
Test coverage
No documented value is exercised by a test (ES, HA, JT, MA, MI, OD, PH, PP, SN, UI).
ES
Error status
HA
Hardware address
JT
Printhead test results
MA
Maintenance alert settings
MI
Maintenance information
OD
Odometer
PH
Printhead life history
PP
Plug and play string
SN
Serial number
UI
USB information

Behavior

~HQ is newer than the 2006 edition of the ZPL II Programming Guide and does not appear in it, so the query names above come from Labelary's command reference. Neither source documents their reply layouts, so this page states nothing about them.

A render request has no device behind it: no odometer, no printhead, no serial number and no USB. The renderer ignores the command, and the page is unchanged. It reports IGNORED_COMMAND at info severity, which does not reach X-Warnings. Labelary is also silent. Of the ten reports, only ES has a counterpart here: the response diagnostics report problems with a format, not with hardware.

Example

An error-status query and a label in one format. The query does nothing; the field is what produces the page.

^XA
~HQES
^FO50,50^A0N,40,40^FDError status^FS
^XZ

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