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NI 9213 CJC Channel

Because the help text said it's possible i've trail and error'd till i've got two solutions. 

The output of both are about the same (I've noticed some more fluctuation on one)

 

Let me explain. 

 

Schematic:

The module is inside a Rittal cabinet. Channel 15 is wired with K-type TC to the cabinet door/ panel. 

The other inputs are wired to a copper panel connector with copper wire. From there it's all TC wire. 

image.png

With this set-up I'd liked to see that

1. When I heat up T0, I don't want to see any fluctuation of T1

2. When I heat up T1, I don't want to see any fluctuation of T2

3. When I heat up T2, I want to see the correct temperature (off course)

 

Than the solutions. Possibility 1 creates a Global Channel programmatically. (Like you can do in MAX). But

as mentioned before I don't want to use MAX because the software runs on multiple machines and I'd make

changes on a daily basis. (development). The help text mentioned 'Another Virtual Channel already in the task'. 

So I've created a task with only channel 15 and later on (When adding the other inputs to the task) set the CJC

channel to the name of this channel. 

 

Possibility 1:

image.png

Possibility 2:

image.png

 

To answer my own questions 1. Correct, 2. Correct, 3. Correct. I've checked the temperature with a IR handheld and it is in 0.2 degree range. 

I slightly noticed some more fluctuation on the second possibility, but 0.2 degree is fine by me. 

 

Oh and I added some foto which I quickly shoot with my phone. 

 

Y. Verburg

 

 

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Hello  asdfasfda,

 

Did you solve the problem? because I typically have the same problem, the probes give different readings for the water in the same case varying around 0.2 Celsius degree. Also, I calibrated the temperature with an accurate thermometer and there is around 0.5 difference in general. I used CJC source type as built-in DAQExpress software. 

 

 

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