HP PCL/PJL reference (PCL 5 Printer Language) - Technical Reference Manual Part II

Glossary-12 EN
Resolution
The high quality output achieved by HP LaserJet printers is due
in part to the ability to lay down a fine grid of “dots” on the page.
The density of this grid is referred to as the printer’s resolution.
Resolution is expressed as a value of dots-per-inch. Until recently,
all HP LaserJet family printers printed at a resolution of 300
dots-per-inch. In a one inch square, the printer could print a dot
anywhere in a grid of up to 300 dots horizontally by 300 dots
vertically, for a total of 90,000 possible dot locations per square
inch (300 × 300 = 90,000).
The LaserJet 4 printer is capable of printing at either 300 or 600 dpi
resolution. At 600 dots-per-inch, it becomes possible to print up to
360,000 dots per square inch (600 × 600 = 360,000).
Robust-Xon
The configuration of ROBUST-XON determines the method by which
Xon signals are generated on the interface. If ROBUST-XON is ON,
an Xon is transmitted from the printer to the host computer when the
printer’s 1 Kbyte I/O buffer has less than 128 data bytes remaining
(896 bytes empty). The printer must be in the on-line state and not
busy. If no data is received, additional Xon’s are transmitted at one
second intervals.
If ROBUST-XON is OFF, the printer sends one Xon signal when the
printer is in the on-line state, and is not busy. The printer does not
send additional Xon signals.
Row
The distance between rows is defined by the current vertical motion
index (VMI).
Rule
A solid-filled rectangular area.
Scalable
PCL 5 printers can use either bitmap or scalable fonts. A bitmap font
is available in its one, defined size only. Scalable fonts, on the other
hand, provide an “outline” for each character which can be scaled by
the PCL 5 printers to produce a large range of character sizes.