03-31-2012 09:31 AM
This is a homework problem yes, I have been going through the readings and I'm having trouble understanding how to do this.
We are able to use the simulated temperature in the activity folder, I'm not seeing where the thermometer is coming from and i want to conert the degrees at the moment (F) to degrees (C). I know the formula for that, but for the life of me I dont' know how I can hook it up.
Solved! Go to Solution.
03-31-2012 09:59 AM
The temperature readings are coming from the "Demo Voltage Read" subVI. there is a hidden control for the values. The inputs to that VI are just dummy inputs.
03-31-2012 10:01 AM
First, thank you for identifying your request as homework.
Is the "activity folder" part of the assignment? We have no idea what is in it.
The best way to get help is to show what you have tried, explain what does not work as you expect, and ask questions as specifically as possible.
What you are trying to do is very simple in LabVIEW. If your class has not covered the LabVIEW basics, please work through the on-line tutorials on Getting Started with LabVIEW.
Lynn
03-31-2012 10:18 AM - edited 03-31-2012 10:19 AM
I successfully, converted to celcius but I'm having some problems. The problems say I need to hook it up to a waveform graph as well as the thermometer.
As you have said I have attempted to do it myself but I ran into problems. I hooked up a numeric indictor to make sure the formula is correct, but how can I make it so the thermoether uses those celcius temperatures? Also how can I wire up the waveform graph correctly, i seem to get a broken wire
the activity folder we only get the simulated demo temp from it, that's all
03-31-2012 11:33 AM
Suggestion 1. Always have the context help window open while programming. If the window is open and you move the wiring tool over the broken wire, the help window will tell you something about the broken wire. In this case it will tell you that the source is a scalar and the sink (the graph) requires an array.
The fix will involve getting your data into an array. I will let you think about ways to do that
Suggestion 2. Array indexes are integers. The coercion dot at the index input of the Index Array function tells you that LV is converting one datatype to another. In this case you are probably OK, but you should always understand what a coercion is doing and be able to explain its consequences. Better woudl be to use the appropriate datatype.
Suggestion 3. The note inside the while loop mentions calling a subVI. This is also a clue to a means of dealing with the issue discussed in Suggestion 1.
Lynn
03-31-2012 12:05 PM - edited 03-31-2012 12:09 PM
the sub vi seems hidden so im not sure how to go about doing this
I'm able to attach it to the waveform graph, i used the build array function and it seems to be plotting the celcius temp correctly.
Now the only problem is getting the celcius temp to display on the thermometer, however, with the subvi being hidden how can I rectifiy this situation
03-31-2012 02:06 PM
There is no hidden subVI. The only thing that is hidden is the indicator. Double click the control. This will highlight the hidden indicator. While highlighted, move it with your cursor keys.
03-31-2012 02:13 PM
oh i see, but im still confused how to make it use celsius instead of fahrenheit
03-31-2012 02:29 PM
Subtract 32, multiply by 5/9.
03-31-2012 03:47 PM
well i get that, but i mean on the thermometer, how do i hook it up