Thermocouples Fail to Update Properly

[LabVIEWNate]

Hello, 

I am trying to read in the data from some variable number of thermocouples, and then select which of the thermocouples to display on a waveform chart.  I am using a PXIe 1082  for my DAQ.  I have attached my VI.  The problem I get is that sometimes (but not always!) if I apply heat to two thermocouples at a time, their response is much slower then when I just apply heat to one thermcouple.  here are pictures of the response of 1 and 2 thermocouples:

I have guessed that it is some sort of timing error and tried to update a few things.  I currently have a producer/consumer system set up because I will eventually need to write this data to a file.  Maybe something there is causing problems. 

Thanks in advance for your help!

[STASHkal]

Nate,

After taking a look at your code I notice a few things.  These are in no order.

1) you have no wait in your acquisition loop.  It might be nice to put a wait in there.

2) try graphing in your producer loop as well as your consumer loop.  See if there is a difference between the two.

3) is this actualy a response rate time or a difference in amplitude? It doesnt look like the second screenshot ever gets above 30.  

4) how are you heating the thermocouples? is it consistent?  

5) if you still think its a response rate problem it would be nice to see an X axis that has more than 2 points.  

Let us know if you discover anything else.