^MN — Media Tracking

Plain English

Tells the printer **how to find the boundary between labels** so the next label starts in the right place on the media. The detection method depends on what the loaded media has: `Y` (Web/gap sensing) — a transmissive sensor sees the gap of light between adjacent die-cut labels; `M` (Mark sensing) — a reflective sensor reads black registration marks printed on the back of the liner at fixed intervals; `N` (Continuous) — no boundary detection at all, the printer indexes by `^LL` label-length value (used for receipt-style roll, fanfold journal stock, or when running die-cut labels with the gap sensor disabled). Some firmware also accepts `W` as an alias for `Y` (web).

When to use

Set this **whenever the loaded media changes type**, then run `~JC` (Set Media Sensor Calibration) so the printer auto-calibrates the gap/mark sensor against the new stock — sensor thresholds set for the previous media will not work for the new one. Symptoms of mismatch: labels print half on / half off the next page (wrong sensor type), or every other label is blank (sensor mis-thresholded). For `N` continuous mode, also set `^LL` to the label length the printer should index by, otherwise feeding behaviour is unpredictable. Persisted via `^JU`.

Syntax

^MNt

Parameters

Example

^XA
^MNY
^XZ

Selects gap (web) sensing for standard die-cut label stock. Pair with `~JC` after loading the new roll so the gap sensor calibrates against the actual gap-vs-label opacity — without that step the printer may mistrack on stock with a different liner thickness.