Decodes the model code (byte 4) to a name, adds the cooling notification
values, and rewords the error-information-2 bit 0 message. That bit is a
media mismatch, which in practice means a monochrome job sent to a black/red
roll — the exact failure seen on the QL-820NWB here.
Checked against "Raster Command Reference, QL-800/810W/820NWB v1.01". Four
things were wrong, all inherited from brother_ql's older-model defaults:
- Invalidate is 400 bytes for this series, not 200.
- The print-quality bit (0x40) is documented as invalid for two-colour
printing; it was being set regardless.
- The media-length valid bit belongs to die-cut stock only. Brother's driver
sends 0x86 for continuous tape, and the manual warns that asserting a valid
flag the loaded media doesn't match returns a "replace media" error.
- ESC i ! (automatic status notification) was missing, and the control codes
now follow the manual's per-page order.
Also confirms the 62 mm geometry we were already using: 12 left margin pins,
696 print area pins, 12 right.
A silent printer no longer blocks printing or reports as unhealthy. printPng
returns confirmed:false when no status came back, so callers don't claim a
label came out when all we know is the bytes were delivered.
The QL-820NWB does not report status over TCP 9100 — brother_ql documents the
same limitation for its network backend. queryStatus therefore became
probeStatus, which reports reachable-with-unknown-state instead of failing.
Also fixes a real bug: the socket was destroyed straight after write, which can
discard data still queued in the kernel send buffer and truncate a ~190 KB job.
Now half-closes with end() and waits for flush, with a grace window for units
that never send FIN.
Takes the PNG renderBadgePng already produces, separates black and red
planes, and sends the job over TCP. Adds a serial queue per printer host so
simultaneous sign-ins cannot collide on the printer's single connection.
Not wired into printer.js yet.
Decodes the 32-byte status frames so cover open, roll empty, cutter jam and
wrong roll width are reported from the printer itself rather than inferred
from brother_ql stderr.
Implements the QL-8xx raster protocol in Node so badge printing no longer
needs the Python brother_ql CLI. Command sequence verified byte-for-byte
against a captured QL-8xx job.
jessikitty