Looking Ahead - HP 7470A Interfacing And Programming Manual

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The P-mask value specifies which of the status-byte conditions will
result in a logical 1 response to a parallel poll over the HP-IB interface.
Looking Ahead
P-Mask
Bit Value
1
2
4
8
16
32
S t a t u s Bit
N u m b e r
0
1
2
3
4
5
M e a n i n g
Pen down
PI or P2 changed
Digitized point available
Initialized
Ready for data; pinch wheels down
Error
For example, a P-mask value of 48 specifies that only bits 4 and 5 (16 +
32) of the status byte can cause the plotter to respond to a parallel poll
with a logical 1 on the appropriate data line.
The plotter, when set to default values or initialized, automatically sets
the E-mask to 223, the S-mask to 0, and the P-mask to 0. An IM
command without parameters or with invalid parameters also sets the
masks to the default values 223,0,0.
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1-14 GETTING STARTED
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Of course you want to use your plotter to create high quality graphic
plots. Most plots fall into one of three broad classes: line graphs, bar
graphs, or pie charts. Chapter 8 contains a discussion of a line graph.
Shown below are a bar graph and a pie chart.
Pie charts are an effective way to show parts of a whole entity; the
slices of the pie are the component parts. The pie chart here has some
segments "exploded" for emphasis. To construct a pie chart, the data is
computed as a percentage of the total and each data value is converted
to the appropriate segment of a full 360-degree circle. A simple circle-
drawing program is found under the PA instruction in Chapter 3. To
create a pie chart you'll need to draw segments of a circle (arcs) and
connect the endpoints of the arcs to the circle's center with plotted
lines.
There are three types of bar graphs; simple bar graphs, stacked bar
graphs, and clustered bar graphs. The simple bar graph here shows that
sales are increasing. Bar
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graphs are essentially a
collection of rectangles;
i.e., four plotted lines.
Each of these rectangles
is filled; refer to the ad­
vanced programming tips
at the end of Chapter 8
to learn how to create a
filled or hatched area. A
stacked bar might be used
to show these same sales
d a t a broken down into
sales by region. Portions
of each b a r would be
colored or shaded differ­
ently to show the sales in
each region. Another way
of showing sales by region
would be to use a separate
bar for each region and
to "cluster" all the bars
for one year together with
a larger space between
each cluster of bars. There
is one cluster for each
year of data.
SMITH UNIVERSITY
STUDENT ENROLLMENT BY COLLEGE
VETERINARY SCIENCE - 2 1
LAW - S *
AGRICULTURE - IB
f O R K T R T - I!
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1973
NET SALES
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III!
1974 1975 1976 1977
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1978
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1979
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GETTING STARTED 1-15