08-08-2014 05:35 PM
Hello!
I need to run this exact code for a continuous acquisition of resistance on sensors I am using at school. Once I select the dmm channel I get this error message:
Error -200077 occurred at Property Node DAQmx Channel (arg 6) in DAQmx Create Channel (AI-Resistance).vi:1->Resistance - Continuous Input.vi
Possible reason(s):
Requested value is not a supported value for this property. The property value may be invalid because it conflicts with another property.
Property: AI.Excit.Src
Requested Value: External
You Can Select: Internal
Channel Name: myDAQ1/dmm
Task Name: _unnamedTask<A>
But when I change the excitation to internal I get this error message:
Error -200077 occurred at Property Node DAQmx Timing (arg 1) in DAQmx Timing (Sample Clock).vi:1->Resistance - Continuous Input.vi
Possible reason(s):
Requested value is not a supported value for this property. The property value may be invalid because it conflicts with another property.
Property: SampTimingType
Requested Value: Sample Clock
You Can Select: On Demand
Task Name: _unnamedTask<C>
I dont understand why it is so difficult to just take the data and write it to a file. I want a graph to display too but writing it to a readable file is most important. Thank you!!!!!!
08-08-2014 06:13 PM
08-08-2014 07:10 PM
Hi Dennis!
It pops up as an example VI under the Labview Example Finder once I searched measuring resistance. It's titled Resistance - Continuous Input.
The error pops up at the start VI (the excitation error), so this should disappear once I put the read VI in a loop? I was testing some loop configurations out but I think I forgot to try that one.
If I try using the Analog outputs instead of dmm do I have to do the same thing? I was getting similar errors when I tried this method too. Thanks so much!
08-08-2014 08:02 PM
08-09-2014 11:49 AM
08-12-2014 04:07 PM
Sorry, I meant analog inputs.
Okay so I got rid of the timing portion, and put the read/write sub VIs in a for loop instead. The only problem Im having is getting rid of the external excitation source. When I try to change it to none, when I run it it automatically changes it back to external. Since it's part of the create channel subVI I do not understand the way around this.
Thanks!
08-12-2014 04:15 PM
Can you post your latest VI?
Things don't just automatically change back and unless there is something programmatically telling it to change back.
08-12-2014 04:46 PM
08-12-2014 04:48 PM
Here are my attached VI's. Im thinking it will be easier to go with VI 2. When you double click the create channel in VI 1 that is how the excitation source is adjustable but it wont stay when I change it.
Also am I doing my for loops correctly? Im just trying to obtain continous sample point readings when I hold the dmm plugs on a resistive strain sensor. From here I want the continuous points to save in one text file!
Thanks so much for the help.
08-12-2014 04:56 PM