Product specifications

Instrumentation Laboratory Exercise 26
You may want to set up the scale on the X-Y plot. To do this,
right- click the plot, and select Properties on the pop- up menu. Go to
the left side bar and click Scale Properties and make the following
setting:
X scale (current): minimum 0 to maximum 0.5
Y scale: minimum 1.5 to maximum 4.5
Ensure that Autoscaling is off for both axes.
Run the program and build up several points on your plot. Rub your
finger against the disk gently slowing the motor to a stall, and watch
what happens with the current. You should see the current increases
significantly as the motor is slowed. You may also notice the voltage
drops somewhat.
Once you have confirmed the X-Y plot is correct, you can add a
routine to save the data to a file. Add a To File box (found under the
I/O > To menu). Right- click it and add two data inputs, label them A
and B. Click the To File: button and enter a file name like Lab3.xls.
Also click on the Clear File box to clear the file at the beginning of
every run.
Finally, double- click and add a WRITE transaction to send TEXT format
information with an EOL turned on. In the dialog box enter the
following:
A, ", ", B
This indicates that the variable A will be written to the file followed
by a space, a comma, and another space, then the variable B. With
the EOL (End Of Line) turned on at the end, this will write your data
in two columns: A, B. This file can be displayed with Microsoft
®
Office
Excel with the Comma separator option selected.
Link A and B to the Motor Voltage and Current as shown:
NOTE
Choose a different file name or file location for each run you wish to save.