LabVIEW

cancel
Showing results for 
Search instead for 
Did you mean: 

Thermocouple with a CB68-LP Board

All,
I know this is a fairly basic question, but I was recently slowed by not having the appropriate hardware, so I'm asking anyway.
 
I have a set of T type thermistors that I want to monitor using LabView.  Due to budgetary limitations, I can't really get any new hardware.  I have a CB68-LP board, with a 6013 DAQ board (also an AMUX series multiplexer).  What's the best way to connect what I have to my thermistors?  It seems like most examples use a SCXI device, but if I'm just measuring a two-channel voltage, do I even need that?  Can I wire all the thermocouples to a common channel on the CB68-LP board for a cold reference? 
 
Thank you for your patience.  Any advice is appreciated (and yes, I did look at the tutorials).
 
Joe
0 Kudos
Message 1 of 7
(3,943 Views)
Please clarify your question.
 
You mention thermocouples and thermistors.  These are 2 completely different kinds of temperature measuring devices.  Since you also say Type T, I assume you are actually using Type T "thermocouples" and not "thermistors".
0 Kudos
Message 2 of 7
(3,927 Views)
Sorry, it was a typo.  You're right, I meant thermocouples the entire way through.  Thanks for your diligence.
0 Kudos
Message 3 of 7
(3,923 Views)
On May 21, 11:10 am, jmarotta <x...@no.email> wrote:
> All,
> I know this is a fairly basic question, but I was recently slowed by not having the appropriate hardware, so I'm asking anyway.
> &nbsp;
> I have a set of T type thermistors that I want to monitor using LabView.&nbsp; Due to budgetary limitations, I can't really get any new hardware.&nbsp; I have a CB68-LP board, with a 6013 DAQ board (also an AMUX series&nbsp;multiplexer).&nbsp; What's the best way to connect what I have to my thermistors?&nbsp; It seems like most examples use a SCXI device, but if I'm just measuring a two-channel voltage, do I even need that?&nbsp; Can I wire all the thermocouples to a common channel on the CB68-LP board for a cold reference?&nbsp;
> &nbsp;
> Thank you for your patience.&nbsp; Any advice is appreciated (and yes, I did look at the tutorials).
> &nbsp;
> Joe

Assuming you meant Type T thermocouples and not Type T thermistors I
suggest you use your AMUX-64T and your PCI-6013 for your measurement.
Use differential inputs for both your AMUX-64T and PCI-6013 for better
noise rejection. Your AMUX-64T can provide cold junction compensation
for your thermocouple. I don't know what a CB68-LP board is but the
information in the National Instruments Catalog and Web Site says you
can make thermocouple temperature measurements using a AMUX-64T and a
PCI-6013. I assume you have the appropriate cable for connecting your
PCI-6013 to your AMUX-64T.

Howard
0 Kudos
Message 4 of 7
(3,913 Views)

Maybe I should clarify. 

I want to know the best way to connect my Type T thermocouples to my 6013 board.  If the AMUX64 board is the preferred method, what is the best wiring scheme for these?  Is there any other reference for doing this?  What sort of VI should I set up, and where are some good examples?

Thank you.

0 Kudos
Message 5 of 7
(3,911 Views)

Hello jmarotta,

 

 

Thanks for your post. I see you have the 6013 with Terminal Block CB68-LP. How many thermal couples do you need to read? If you just use the 6013 I recommended using differential mode as well to connect your thermal couples. This will allow you to connect 1 thermal couple per channel. The use of bias resistors is also required as this will give the best noise rejection. This however will allow you to only read 8 thermal couples at a time. Take a look at Table 1 from the link below. This shows the best way to hook up different sensors to your DAQ card.

Field Wiring and Noise Considerations for Analog Signals

 

I see that you want to use the AMUX-64. This accessory uses the traditional DAQ drivers so if you want to use DAQmx then the AMUX-64 is not supported. There are some great example programs for taking thermal couple measurements in the LabVIEW example finder. If you go to Help >> Find examples this will open the example finder and under the search tab type in “thermocouples”. This will bring up some great DAQmx examples. Please post back if any of this is un clear and Good Luck.

Corby_B

 
0 Kudos
Message 6 of 7
(3,885 Views)
On May 21, 4:10 pm, jmarotta <x...@no.email> wrote:
> Maybe I should clarify.&nbsp;
> I want to know the best way to connect my Type T thermocouples to my 6013 board.&nbsp; If the AMUX64 board is the preferred method, what is the best wiring scheme for these?&nbsp; Is there any other reference for doing this?&nbsp; What sort of VI should I set up, and where are some good examples?
> Thank you.

There are some example vi's that come with Labview that can acquire
data from thermocouples using a PCI-6013 MIO board. Follow this path
to get to the vi's Finding Examples | Hardware input and output |
DAQmx | Analog measurements temperature | Select "Acq. Thermocouple
sample.vi" when you want to manually control the sampling rate or
"Cont. acq thermocouple sample SW timed.vi" when you want to control
the sampling rate with software. The requirements box says these will
work with a PCI-6013.

I will provide more information on wiring your thermocouples to your
AMUX-64T some time this weekend. In the meantime if you don't have a
copy of the AMUX-64t User Guide download a copy in PDF format from
ni.com/manuals.

Howard
0 Kudos
Message 7 of 7
(3,879 Views)