The User Defined Character - HP 7470A Interfacing And Programming Manual

The User Defined Character
Instruction, UC
DESCNPTIUN The user defined character instruction, UC, provides
the means to draw characters of your own design. It is not included in
the instruction set of the 7470 plotter with an HP—IL interface.
M This instruction can be used to create symbolsnot includedin
the plotter's character sets, to draw logos, or to create your own
character fonts.
UC (pen control,)X—increment,Y-increment,(pen control,)
(X—increment,Y—increment,)...,...,terminator
or
UC terminator
EXPLANATIONThe instruction is treated as a NOP instruction on a
plotter with an HP-IL interface (refer to Appendix C).
The following paragraphs 'apply to plotters with either an HP-IB or
RS—232—C interface.
Each segment of the character is drawn on a character grid according
to the three types of parameters in the command.
A grid is established on each character—spacefield by dividing it into
six horizontal units and 16 vertical units. The size of the character­
space field and, hence, the grid unit is set by the current size command.
The size of the character—spacefield and thus the grid is always twice
the current character height and 11/2 t imes the current character width.
In order to draw a user defined character the same size as a character
drawn with a label command, the user defined character must be de­
signed in the lower-left corner of the grid with a width of four grid units
and a height of eight grid units.
The three types of parameters are described below.
The X— and Y—incrementsshould appear in pairs and must be greater
than -99 and less than +99. They specify, in decimal format, the
number of X— or Y—gridunits that the pen will move horizontally or
vertically from the current pen position. The parameters need not be
integers; fractional portions are used. Positive X-increment parameters
move the pen in the direction of labeling, i.e., to the right with default
label direction, and positive Y—increment p arameters move the pen up
with default label direction. Negative parameters move the pen in the
opposite direction. Unmatched X,Y increments are discarded, error 2 is
set, and the rest of the character is drawn.
Pen control parameters must be less than or equal to -99 or greater
than or equal to +99. A positive pen control parameter lowers the pen; a
LABELING 5-19