Temperature Control Program
Page by: Andrew Sampino
The temperature control program is a LabView VI, which checks and regulates the temperature of the Fiber Heating Box. Once the program is initiated it will turn on the hotplate in the heating box and keep it on until either the temperature climbs too high or a user has indicated a stop or stop condition. The program outputs commands to a netbooter, which is the hotplate's voltage source, and reads inputs from thermistors through a DAQ.
The front panel displays a waveform chart, which will display each temperature measurement, digital temperature and time displays, and various controls to set parameters.
Instructions for a Heating Run
Before setting the program to run as desired, the physical setup must first be appropriately configured. To set the hotplate temperature, plug it into a regular wall outlet and turn the knob until the temperature display reads 140 degrees Celsius, then unplug it. Next, plug the hotplate into outlet one on the correct netbooter (usually the top netbooter) as the state of this outlet will be controlled by the program. Finally, plug all fans in and look to see that they are actually spinning.
In order to perform a heating run there are a number of parameters, which can be found of the front panel that must be set properly. The conditions for a normal run are listed below:
Samples/Channel: 1 is sufficient here, increase for more data points.
Rate: 1 is sufficient here, increase for more data points.
Sample Mode: FiniteSamples
Save your file?: Pressed if you want to save the run, unpressed if you don't.
STOP: Must be unpressed at program start.
Control Manually: Automatic
Target Temperature: 175
Timed Heater Turn off: any desired time. (in seconds)
Start Timer: On to start timer when the program starts, off otherwise.
Once all of these are set appropriately the run can begin. Pressing the LabView run button will initiate all relevant processes and the hotplate should turn on within the first twenty seconds assuming the interior box temperature is less than 190 degrees Fahrenheit. When the
Note that the program will shut the hotplate off for the rest of the run if the highest temperature passes 190 degrees Fahrenheit
Program logic
The overarching logic behind the program is to turn the hotplate off when the box is too hot and on when it is too cold. All of the code is contained in a sequence structure consisting of two frames. The first frame contains nearly all of the code and is what drives all operating functions, the second frame contains a sub VI, which shuts off the netbooter (and therefore the hotplate).