Whether can scb 68 connect to PCI-7813R to measure thermocouple with CJC?

[templor]

Hi There,

I am a new guy for this device.

I suppose to use SCB-68 to measure temperature with thermocouples by CJC function.

Our lab has a PCI-7831R and I have install Labview2009, NI-RIO3.3.0 and DAQmx9.5.1 in my computer.

When I opened Measurement& Automation Explorer, only RIO0 can be found, and if use righ click on it, only refresh is shown, no SCB-68 can be found.

I have no idea what's wrong about it, and whether I can use this PCI to realize CJC function.

Thanks.

[Beau_H]

Hey templor,

The PCI-7813R does not us the DAQmx driver, so you don't configure a task in Measurement & Automation Explorer the way you can for a standard DAQ card. If you go https://www.ni.com/docs/en-US/bundle/pci-pcie-pxi-781x-783x-784x-785x-getting-started/resource/37325... pg 8 goes through getting started and how to take your first measurement with your R-Series Card. 

As far as the detecting the SCB-68 goes, the Reference manual for the 7813R on pg 60 and it shows how to configure the Dip-Switches on the SCB-68 to be configured for general purpose connector block. So look at the reference guide on the lid of the SCB-68 to find the I/O terminal that corresponds to the I/O pin.

Hope this helps.

[templor]

Because I have checked on your website, there is a solution for how to use the Cold Junction Compensation on the SCB-68, which is shown the PCI-6251 is configured to realize this function.

So I am not sure whether PCI-7831R can also do it with same steps as PCI-6251.

[Beau_H]

Hey templor,

So here's the thing, I believe you were looking at this KnowledgeBase https://knowledge.ni.com/KnowledgeArticleDetails?id=kA00Z0000019MnvSAE&l=en-US because you are using a R-Series card it with the SCB-68 it needs to configured as a straight through board. This means that you can't use the CJC on the SCB-68, you would need to set one AI pin to be your CJ Reference and the other AI pins taking thermocouple readings would all be referencing that AI pin and in software you take the difference to get your actual temperature.  

One question, is there a reason you have to do this in FPGA? It sounds like if all you need to do is take a temperature measurement you could do that with a standard multifunction DAQ, that you could connect to the SCB-68 and could configure it for CJC?

[templor]

Hi Beau,

Thanks for your reply.

Because I only found PCI-7831R in our lab left by former colleague at first, I supposed to use it to test.

Now I have borrowed one PCI-6251, whether that means I can use SCB-68 with CJC, and what kind of software I should install beside what I have done?

BTW, may I test and record another tens of milivolt voltage during the temperature test by only one SCB-68, or what kind of other hardware and software is needed?

Thanks.

[Beau_H]

Hey templor,

A good place to start is https://www.ni.com/en-us/support/model.pci-6251.html you will find links to all the import information about that card there. As far as the software you need, the versions of DAQmx and LabVIEW you have installed should be fine. 

Hope this helps,

[templor]

Many thanks.