Setting The Scaling Points; Preparing Equal-Sized Plots - HP 7470A Operator's Manual

locations serve different purposes, depending on the programming
language being used. When programming in HP-GL, they are used in
conjunction with the scaling command SC to establish a user-unit
coordinate system.
and when using some prepackaged software, they are used to establish
software hard·clip plotting limits. Once the hard-clip plotting limits are
defined, scaling of the plot is adjusted by the computer to fit your plot
within the hard-clip plotting limits. Thus, you can draw your plot full­
page size, or you can move PI and P2 closer together to reduce the size
of your plot. This feature is useful when you wish to draw more than
one plot on the same page.

Setting the Scaling Points

The locations of scaling points PI and P2 can be changed manually
from the front panel or programmatically With the HP-GL command
IP. Refer to the Interfacing and Programming Manual for instructions
on how to set the scaling points programmatically.
P2 can be moved without changing the position of PI. However, when
PI moves, P2 moves so that the X- and V-distances between PI and P2
do not change. Default positions for PI and P2 can be reestablished by
any of the following methods:
power-up initialization,
•
execution of HP-GL commands IN or IP;,
•
moving the paper loading lever to the
•
simultaneously pressing
The procedure for manually relocating PI and P2 is as follows:
NOTE:
Always set PI first, since P2 moves when PI
1. Using the arrow pushbuttons, position the pen at the new location
chosen for PI.
2. Press
ENTER
3. Using the arrow push buttons, position the pen at the location
chosen for P2.
4. Press
ENTER
5. To check the new points, press
move to the new PI point, then to the new P2 point.

Preparing Equal-Sized Plots

Automatic positioning of P2 as PI is moved can be used advanta­
geously in applications such
same page. This function is illustrated in the following diagram. The
24
When
programming in BASIC graphics statements,
and
ENTER
simultaneously with
simultaneously with
preparing two equal-sized plots on the
as
PAPER LOAD I
(front-panel reset).
VIEW
is
moved
to store the new location of PI.
Pl
to store the new location of
P2
then press The pen should
Pl, P2.
position , then
. •
P2.