Thermometer Vi

[Fred Whitman]

I'm having a problem with the Thermometer vi.  I have a VI that I'm using log about 25 signals and one of these is a thermistor. As my vi is running the thermometer display and digital readout are cycling between 0 and the actual voltage of the thermistor everytime my daq card samples.

My vi is aquiring 1 sample at a rate of 20.  If I change the rate the temperature displays  cycling increases or descrease dependingon whether I increase or decrease the rate.If I set the rate to 100 the display doesn't change but I think it is still happening but I just can't see it changing.

I hope I explained that well enough that someone can help me with my problem.

System Setup

PCI-6225

SCB-68

TBX-68

Vista OS

Thanks 

-Fred

[nathand]

Can you post your code?

[Fred Whitman]

Here is my VI and I also wanted to add that I've no training with Labview.  Everything I have learned I've taught myself so if you have any advice on how to improve it I would appreciate it.

[nathand]

I don't see anything obviously wrong that would cause the problem you described; could you also include your subVIs (in a .zip), or at least the Pad Signals subVI which looks like it outputs the temperature?  Also, are you getting consistent cycling between 0 and your value (ie, it changes every time through the loop, or some other predictable interval) or is it random?  If it's somewhat random that would suggest an electrical problem, not a software error... check all your wiring, and also see if the same thing happens if you move the temperature reading to a different channel.

[Fred Whitman]

Here are the subvi's you requested.

-Fred

[nathand]

I don't see anything obviously wrong with your code, but maybe someone else will.  Have you tried writing a simple test VI that only reads that that single thermistor channel?  If you view the thermistor channel in Measurement and Automation Explorer, do you see the same behavior?  You may also want to scan your channels in consecutive order, it looks like your DAQ Setup subVI adds them to the channel in somewhat random order I seem to recall that some DAQ cards don't like that (although I could be wrong, and I don't know about your card in particular).