When the printer is printing or feeding media, it looks for small, naturally-occurring variations in length, either from label to label on a roll or from roll to roll of loaded media.
At the start of a print job or a media-feed action, if the printer senses that the expected media length or inter-label gap falls outside the acceptable range of variations, it auto-initiates a media-length calibration.
Automatic media sensing methods are the same for EPL and ZPL label formats and programming.
When feeding the media, if the printer does not detect label gaps or black marks (or notches with blackline sensing) for the default maximum label length distance of 1 meter (39 in.), it switches to continuous media mode (typically used for receipts).
The printer retains these settings until you change them using software such as ZebraDesigner, using ZPL or EPL programming, or with manual calibration which is recommended if you have loaded media of a different batch, size, or date than that of the prior roll.
You can reduce the automatic media type maximum-sensing distance using the
^ML
ZPL Maximum Label Length command.
Set this distance to NO LESS THAN two times the longest label being printed. If the longest label being printed is 4 in. wide by 6 in. long, you can reduce this distance from the default 39 in. to 12 in. (2 x 6 in.).
You can set the printer to run a short media calibration either after printer power-up or when the printer cover is closed with printer power ON. With this setting, the printer feeds several labels while calibrating.
If the printer has difficulty auto-detecting the media type and auto-calibrating, run a longer calibration using
Manual Calibration. During manual calibration, your printer prints a graph of sensor operation specific to the media that is loaded. This method disables the printer’s automatic media sensing until its default parameters are reset to their factory defaults using the four-flash
FEED
button mode. See
FEED Button Modes.
You can turn automatic media calibration on or off and modify it as needed.
Some print jobs may need to use entire media rolls. To accommodate these scenarios, you can modify two conditions (power up with media loaded and closing the printer with power on) individually using the
^MF
ZPL Media Feed command. This command is used primarily when what you need is automatic media sensing and calibration.
For automatic media calibration in the context of dynamic media calibration (label to label), refer to the
^XS
command in the ZPL Programming Guide.
Do NOT change these settings if multiple media types of different lengths, material or detection methods (web/gap, black mark, notches or continuous) are in use.
You can refine the automatic media calibration and detection process to match the media type loaded into the printer. Use the
^MN
ZPL Media Tracking command to set the media type.
At times, the printer may auto-sense preprinted media as gaps between labels. It may also interpret any print that is on the media liner backing as black marks.
If you have set the
^MN
ZPL Programming parameter for continuous media, the printer does not perform auto-calibration. The
^MN
command supports the
^MNA
automatic calibration parameter. Use this parameter to return the printer to its defaults if you want it to resume auto-detection and sensing of all media types.
