Paxar PCL command reference

The label format language of SNAP 500 and SNAP 700 printers · updated 1 October 2026

SNAP printers read a format language the firmware itself calls PCL. It is not HP PCL, which uses ESC sequences, and it is not Zebra ZPL, which uses ^XA … ^XZ. Here every command starts with a tilde, and a format runs from ~XA to ~XZ~.

Syntax

• Every command starts with ~, followed by a two-letter uppercase code and its value. The value ends at the next ~, CR or LF.
• Two commands have a single letter: ~D (data) and ~I (image). Everything after the letter is the value, so ~DTOP HEAD is the data TOP HEAD, not a command DT.
• ~XZ~ and ~ZZnnnnn~ end with an extra tilde. A tilde followed by another tilde, CR or LF is empty and is ignored.
• Line breaks are optional: a whole format can be a single line.
• After ~I comes binary PCX data, which may contain tilde, CR and LF bytes. That part cannot be read as text.

Structure of a job

~XA~XW1000~XP3250~XD300 …     format header
~FA08~FDF~FR0~FW0586~FP1313 … one field per line (text, line, logo, image)
~XZ~                          end of the format
~ZD00                         always 00
~ZITESTPAT1                   format name (optional)
~DTOP HEAD                    one ~D per data field, in field order
~I<binary PCX>                one ~I per ~FM field, in order
~ZZ50000~                     batch quantity

How data reaches the fields confirmed

• ~D lines are consumed in order by every field that is not a line (~FL) and not a job image (~FM).
• ~I blocks are consumed in order by the ~FM fields.
• In ~FAnn, nn is the maximum number of characters the field accepts. Longer data is cut by the printer.

Header · ~X

Fields · ~F

Geometry: ~FW grows upwards and ~FP grows along the label length, with the origin at the bottom-left corner of the tag. At rotation 0, text runs along the length. This was checked against printed labels.

Text parameters · ~A

Line parameters · ~L

Graphic parameters · ~G

Logos and job images carry ~GM, ~GT, ~GU, ~GE and ~GR. ~GM is 3 on ~FG and 4 on ~FM, which suggests it marks where the graphic comes from. The rest is unknown.

Data, images and batch · ~Z

Stations

A tag can be printed by more than one head. ~FDF is the top head (front) and ~FDB the bottom head (back). Machines with three stations use ~FD1, ~FD2 and ~FD3. Each field belongs to exactly one station.

Volatile logos and queries

The firmware changelog mentions commands that never appeared in the files we have: ~V downloads a volatile logo that lives in memory until ~VD~ erases it or the printer is switched off, and ~QRR asks the printer for a file name. They are listed here for completeness and are unknown in practice.

Barcodes

A barcode is a ~FB field and its data comes in the usual ~D line. Which symbologies the printer itself can draw is settled — its firmware names them one by one, and its error messages (CODE 39 BAD DATA, BAD UPCE DATA, BARCODE FIT ERROR, BARCODE VERIFY ERROR) are symbology specific:

What is not settled is the parameter inside the field that picks the symbology, the module width, and whether the human readable line is a field of its own. No format we have access to contains a barcode field, so for now the viewer lets you choose the symbology by hand and draws Code 39, Code 128, EAN-13, EAN-8, UPC-A and Interleaved 2 of 5 from the field data.

Care symbols

A care symbol field is an ordinary text field with ~AC999. The printer runs every character of the data through its code page 999 table, which returns the code point of the symbol inside the care symbol font — one character in, one symbol out. The table is regular: symbol number N is the ASCII character 0x21 + N, so # is symbol 2, 9 is Do Not Wash and P is Size Small. ~AC998 does the same for NAFTA symbols.

Two details are still open. The field length in ~FAnn counts symbols, and the printer firmware notes that the host sends three characters per symbol — so the design software seems to encode each symbol as a three-digit code before the printer reduces it to one byte. And the care symbol fonts themselves are licensed by the printer manufacturer, so Labelisk cannot redistribute them: a care symbol field renders with a warning instead of the symbols.

If you have a format with care symbols, or one with a barcode, send it over with a photo of the printed tag. That is what turns the inferred rows above into confirmed ones.

Example

A complete two-sided label, with a frame, text fields and a barcode, is loaded by default in the viewer. Change a number there and the drawing follows along, which is the quickest way to understand a command.