BNC-2090a and thermocoupole

[pooh1]

Dear folks,

I have pci-6251 DAQ board and BNC-6090a accessory. Is there any way to read thermocouple into LABVIEW? BNC-6090a does not have cold jucntion compensation, right?? Then, what I have to do? Do I have to buy SCB-68 accessory to read thermocouple???

Please help me....

[Chris_W.]

Hi pooh1,

You are correct, that the BNC-2090a does not have cold junction compensation, which you would likely want for a thermocouple measurement. Also, unless your thermocouples were BNC connected you wouldn't really be able to use it for thermocouple measurements unless you did some surgery to a BNC cable. I would not advise this, however. So, as you stated in your post, for a cheaper terminal block to measure your thermocouple readings an SCB-68 would be a good choice, and this does have the cold junction compensation. Another option, is a TC-2095 thermocouple terminal block.

Chris N White

High Speed Products Group

[pooh1]

Dear Chris,

I just placed an order for SCB-68. This might be stupid question. Can I use SCB-68 and BNC-2090a at the same time with my PCI-6251 card?

Thanks,

Young Rae

[Chris_W.]

Hi Young Rae,

You can use both of these two terminal block with your PCI-6251 at the same time using the front and back 68 pin connectors on your BNC-2090a, to create a pass through connection to your SCB-68. You can see a circuitry overview about this in the user manual on page 16/50. 

http://digital.ni.com/manuals.nsf/websearch/C7BD135F38BAA43F8625727D007166FD

However, if you do this, you need to make sure that you are not using the same input/output channels simultaneously on both of the terminal blocks. You cannot read on ai0 on the BNC-2090a and ai0 of the SCB-68 at the same time. On one of the terminal blocks, that channel would have to be unconnected.

Chris N White

High Speed Products Group

[pooh1]

Dear Chris,

I got the SCB-68 but I don't know which calbe I have to use to connect BNC-2090a and SCB-68. Would you let me know part number for the cable??

Thanks,

Young Rae

[Chris_W.]

HI Young Rae,

The following link is the cable you would use. This information is also available in the product data sheet.

http://sine.ni.com/nips/cds/view/p/lang/en/nid/11799

Thanks.

Chris N White

High Speed Products Group