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Problem reading thermocouples with SCXI-1102 w/ SCXI-1303

Well it didn't take long for the problems to start.  Hopefully this is just a case of me doing something wrong.

I have 2 J-Type thermocouples that I have connected to Ch.0 & Ch.1 of my SCXI-1303 Accessory. 

Looking at the Virtual Channels individually in MAX, I can see them both respond as expected to temperature change.  But as soon as I put two Virtual Channels together in one task, I can no long read the thermocouples individually.  Touch one, and both respond equally to the temperature change. 

I've tried setting up the Task a number of different ways.  But it doesn't seem to make any difference. 

In my application I need to continually monitor 34 thermocouples.  I must be doing something wrong....any ideas?     


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Patrick Allen: FunctionalityUnlimited.ca
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1148249

pallen,

Can you post a screenshot of your task configuration or your configuration specs for your task and each virtual channel? Does each thermocouple need to be configured differently?

If all the thermocouples are going to have the same settings then you could just create a task and add the physical channels to the task rather than adding virtual channels to the task.

What other ways have you tried setting up your task?

Ryan N
National Instruments
Application Engineer
ni.com/support
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Hi Ryan,

Thanks for your response.

Actually, I meant to respond to my own post after I got the issue solved with a little help from an NI AE. 

As I suspected, I had something configured incorrectly.  I had set the communicating slot on the SCXI rack to the wrong port.  What made it difficult to troubleshoot was that I was getting a signal.  So it seemed like it was almost working. 

Putting the thermocouple on another module actually led to discovering the problem.  The other module wasn't reading even one thermocouple properly, so something was obviously really wrong somewhere. 

I wish I could remember the AE's name.  I'd give him 5 stars.  *Grin*

At least I'll be able to enjoy this weekend without having this little problem nagging at me.

Thanks for the excellent support NI!
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Patrick Allen: FunctionalityUnlimited.ca
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