~JC
Set Media Sensor CalibrationPreview: not drawnTells the printer to measure the media it is loaded with, which is the fix for most feeding and blank-label problems.
Syntax
~JCThis command takes no parameters.
How it works
~JC starts a calibration: the printer feeds a couple of labels, watches its sensors, and works out where the gaps or marks are and how transparent the liner is. Everything it does afterwards to find the top of a label rests on that measurement.
It is the standard answer when a printer starts feeding blank labels, stops in the wrong place, or prints one image across two labels. Those are all symptoms of the printer's idea of the media no longer matching the roll in it.
Calibrate after changing media, and after changing ^MN — a sensing mode set against a calibration taken on different stock is the combination that produces the strangest results.
Example
~JC
^XA
^FO50,50^A0N,40^FDAfter calibration^FS
^XZRendering…
How the preview on this site handles it
Not drawn, and not drawable: ~JC makes a physical printer feed labels and read its own sensors. Being a tilde command it sits outside ^XA…^XZ, so the preview skips past it and draws the format that follows normally.
Common mistakes
- Sending it on every label. Each calibration feeds labels, so a ~JC in a template wastes stock on every print.
- Calibrating before setting the media type and tracking mode. The measurement is taken against those settings — change them first.
- Expecting it to fix a format problem. If the label prints in the wrong place on correctly fed stock, the issue is ^LH, ^LL or ^PW, not calibration.