Sentry Industries CA756 - Manual (Page 59)

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As you can see above, the Trace and Zoom functions can
be used to locate the pointer at an approximate point, and
then produces a readout of the coordinates.
To return the graph to its original size, press
(Important)
The pointer does not move at fixed intervals. It follows the
dots on the display. Because of this, the values provided
for coordinates are approximate.
* The Trace function can only be used immediately after a
graph is drawn. This function cannot be used if other
calculations or operations (except and
have been employed after a graph has been drawn.
* The Trace function cannot be written into a program.
* When the format: " formula formula " is
executed and a graph is drawn by pressing directly
after executing the Trace function during halt status, the
previous coordinate value remains on the display. After
the Trace function is executed and the text display is
brought up using the key, pressing causes the
next graph to appear and the coordinate value to clear.
Examine the above using
2 5.
Plot function
The Plot function is used to mark a point on the screen of a
graph display. The point can be moved left, right, up and
down using the cursor keys, and the coordinates for the
graph displayed can be read. Two points can also be
connected by a straight line .
Press and specify the x-and y-coordinates after
the "Plot" message.
Line function
The Line function makes it possible to connect two points
(including the blinking pointer ) created with the Plot
function with a straight line. With this function, user
generated lines can be added to graphs to make them
easier to read.
Draw perpendiculars from point (2,0) on the x-
axis to its intersection with the graph for y=3x.
Then draw a line from the point of intersection
to the y-axis.
The range values for the graph are as follows:
Xmin: -2 Ymin: -2
Xmax: 5 Ymax : 10
Xscl: 1 Yscl: 2
Clear the graph display and draw the graph for y=3x .