Remote strain gages

[Tom_SAVU]

I have to measure from eight strain gage channels disposed at 100 m from the PC. The cheapest solution I found is to use a SC-2043-SG in a CA-1000 enclosure, a NI USB-6008 and a USB extender.
Question 1: in its User Manual, is mentioned that the outputs of SC-2043-SG are NRSE signals. Does this comply with the input specifications of NI USB-6008 ?
Question 2: is there enough space for inserting the NI USB-6008 in the CA-1000 enclosure (using some "home made" fixtures) and are there any thermal problems ?
Thank you !

[sergesl]

I have to measure from eight strain gage channels disposed at 100 m from the PC. The cheapest solution I found is to use a SC-2043-SG in a CA-1000 enclosure, a NI USB-6008 and a USB extender.
Question 1: in its User Manual, is mentioned that the outputs of SC-2043-SG are NRSE signals. Does this comply with the input specifications of NI USB-6008 ?
A: the 6008 only has differential and RSE input configurations. However, you can attempt to make it work by using the 6008 in differential mode and connecting AISENSE to the negative pin on each of the channels. NRSE is sort of like differential mode.

Question 2: is there enough space for inserting the NI USB-6008 in the CA-1000 enclosure (using some "home made" fixtures) and are there any thermal problems ?
A: there appear to be enough space to put both in the enclosure. The problem maybe be the thickness of the enclosure. It is 4.39 while the thickness of the 2043 is 4.6. The difference is in the millimeters, but could be a problem. Other than that, there should not be any other problem.
You can check these dimensions in the following PDFs:
http://www.ni.com/pdf/manuals/321738a.pdf
http://www.ni.com/pdf/manuals/371303a.pdf
http://www.ni.com/pdf/manuals/371201a.pdf

Good luck on your project

[Tom_SAVU]

Dear Serges,
Thank you very much for your answer.
Installing SC-2043-SG in the CA-1000 is not a problem: it's not 4.6 cm high, because its originally standoffs are removed (see page 6 of 321738a.pdf).
Using 6008 in DIFF mode means only four channels, so I will need two 6008s.
After seeing figure 3 at the same page I am not so sure that I will be able to insert two 6008s in the same CA-1000 enclosure with a SC-2043-SG. May be I will have to use a second enclosure.
Tom

[sergesl]

Before you get a second 6008 try to use one in RSE. but have its ground connected to the NRSE of the 2043. This might work.

[Tom_SAVU]

Dear Serges,
I think that the physical dimensions mentioned in the CA-1000 Installation Guide (30.63 x 25.40 x 4.39 cm) are external dimensions.
Do you know where can I find the dimensions for the inside ?
Thank you.
Tom

[Tom_SAVU]

Dear Serges,
Thank you very much, I will try this.
Tom

[sergesl]

You can view the dimensional drawing at http://www.ni.com/pdf/hardref/us/CA_1000.pdf

[Tom_SAVU]

Thanks a lot. Now it's all clear.
Tom