FIGURE 1
PHOTO 4
PHOTO 6
PHOTO 5
PHOTO 7
these, and finally the number of cycles to complete in the
settings box on the left hand side of the front panel labeled
SETTINGS. After pressing the START/RUN button, the VI will
then begin heating the chamber until the upper temperature is
reached or the cycle time has expired, whichever occurs first.
The button is gray and displays START until it is pressed; it then
turns green and displays RUN. If the user presses the STOP
button or the number of cycles completed equals the desired
number of cycles, the VI will stop execution.
In the righthand box of the front panel labeled SYSTEM
MONITOR, the user will see each cycle’s time as it progresses,
the number of the cycle being executed, as well as the temperatures inside and outside of the chamber. The five LEDs in the
system monitor box will indicate the status of several items. The
OPEN LID LED will turn red if the box lid is open. The LOWER
LED will be green when the system is in a cycle maintaining the
lower set temperature. The UPPER LED will be green when the
system is in a cycle maintaining the upper set temperature. The
SHUTTER LED will be green when the shutter is blown open by
the fan. Finally, the LDR LED will be green when the lights are
on and the LDR’s voltage drops below a certain point verifying
that the lights are actually on. A chart of the temperatures
versus time is located on the bottom of the front panel.
It would be very involved and tedious to explain how to
build the VI from scratch. I believe a better way would be to
explain how the VI operates in general. If there are readers
who desire copies of the working VI, they can send an email to
me at
ward@suu.edu requesting one. A copy is also available
FIGURE 2
SERVO 07.2009
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