This document describes an active learning report for a LabVIEW VI that measures and plots temperature. The VI continuously measures temperature every second, plots it on a chart along with upper and lower limits. If the temperature is outside the limits, a warning LED turns on. The user can set the limits and temperature amplitude from the front panel. The VI includes controls for temperature, limits, a warning LED, and a chart to plot temperature over time. Block diagrams show comparisons to the limits, merging the signals for the chart, and a time delay in a loop to measure every second.

1. KMEM 3116:
INSTRUMENTATION AND
MEASUREMENT TECHNIQUES
ACTIVE LEARNING 1 REPORT
NAME : AHMAD ALIFF BIN AZMI
MATRIC NO. : KEB090001

2. QUESTION: Build a VI that continuously measure the temperature one per second
and display the temperature on a chart in a scope mode. If the temperature goes
above or below the preset limits, the VI turns on the front panel LED. The chart should
plot the temperature, as well as the upper and lower temperature limits. You should
be able to set the limits from the front panel. The VI front panel should also include
controls to vary the amplitude of the signals generated.
FLOW CHART
Start
Input Plot Chart
Current Temp
>= High Limit
NO
Current Temp
NO
<= Low Limit
YES
YES
Warning LED = Warning LED =
True False
End

3. INPUTS AND OUTPUTS
Type Name Properties
Dial (Numeric Control) Current Temp Double-Precision
Numeric Control High Limit Double-Precision
Numeric Control Low Limit Double-Precision
Waveform Chart Temperature Plotting Scope mode, 3 plots:
Chart Current, Higher and Lower
limit
Boolean Indicator Warning LED Turned ON when not in
range
IMPLEMENTATION
1. Create a Dial for the current temperature.
- Place a Dial on the front panel.
- Change the label to Current Temp.
- Right-click the control, select Representation, and confirm that the
representation type is set to double precision
2. Create a numeric control for the high limit.
- Place a Numeric Control on the front panel.
- Change the label of the numeric control to High Limit.
- Right-click the control, select Representation, and confirm that the
representation type is set to double precision
3. Create a numeric control for the low limit.
- Hold down the <Ctrl> key and click and drag the High Limit numeric control to
create a copy of the control.
- Change the label text of the new numeric control to Low Limit.
4. Create a Round LED for the warning Boolean.
- Place a Round LED on the front panel.
- Change the label text of the Boolean indicator to Warning LED.
5. Create the waveform chart
- Right click > Graph Indicators > Waveform Chart
- Right click at the chart > Properties > Under the Appearance tab, change the
update mode to scope mode.
- Tick ‘Show Plot Legend’ and change to 3 plots shown.
- Rename the plot to Current Temp, High Limit and Low Limit.

4. Figure 1: Front Panel
BLOCK DIAGRAM
Figure 2: Block Diagram

5. 1. The Current Temp and High Limit are compared.
A Greater Or Equal? function is placed on the block diagram.
The Current Temp terminal is wired to the x input terminal of the Greater
Or Equal? function.
The High Limit is wired to the y input terminal of the Greater Or Equal?
function.
2. The Current Temp and Low Limit are compared.
A Less Or Equal ?function is placed on the block diagram.
The Current Temp terminal is wired to the x input terminal of the Less Or
Equal? function.
The Low Limit terminal is wired to the y input terminal of the Less Or Equal?
function.
3. The Warning LED is generated.
A Not Equal function is placed to the left of the Warning LED
The output of the Less Or Equal ?functionis wired to the x input terminal of
the Not Equal function.
The output of the Greater Or Equal ?functionis wired to the y input terminal
of the Not Equal function.
The output of the Not Equal function is wired to the Warning LED.
4. Place the Merge Signal function besides Waveform Chart. (Right click > Signal
Manipulation > Merge Signal). Wired Current Temp, High Limit and Low Limit to
the Merge Signal input terminal.
5. While Loop function is placed entire circuit to make sure the process is running
unless being stop by the user.
6. Time Delay funtion is placed inside the While Loop and set with 1 second. This is to
control the chart plotting with 1 second delay.
7. The VI is saved.