cFP-RTD-124 Errors

[AU777]

Hi.

I am having a problem (since new) with a cFP-1804 and cFP-RTD-124.

When the unit is powered up all of the connected RTD channels display the current temperature as -30ish degrees C with a lot of noise even though the RTD elements are at room temperature. However, if the D37 connector linking the RTD elements to the cFP back plane is disconnected and reconnected (hot) all of the connected RTD channels read correctly with no noise.

I have updated the 1804's firmware to Rev 6.05 and I am running LV 7.1 and Max 4. It does not matter if I run Max or a vi, as soon as the RTD’s are disconnected and reconnected everything straightens out.

I would appreciate your thoughts,

Paul.

PS. Rebooting the 1804 through Max or manually resetting it makes no difference, only unplugging and reconnecting the RTD's.

Message Edited by AU777 on 12-12-2007 12:54 AM

[Peter Lamb]

Hi AU777,

I'm sorry for this behavior that you're seeing.  After doing a little bit of looking at NI's online knowledgebases, I found this one that appears to address the issue at hand:

http://digital.ni.com/public.nsf/allkb/3784655EFDDDE51E862572CF007A7D62?OpenDocument

Please take a look at it and see if it is pertinent to the behavior you're seeing and part number version you're working with.

Best,

Peter

[AU777 · Accepted solution]

Hi Peter.

Thank you for your reply.

That is it exactly. I will contact NI here in Aus and organise to have it repaired.

Thanks again,

Paul.

[AU777]

Hi again Peter.

A thought…

Can you find out if the bug is caused by something simple like a noisy internal supply or something that can be fixed by modifying component values or adding additional components? If so, is it possible for us to do the repair? I ask because the unit is in operation and we will need to minimise the downtime while it is being repaired, fixing it in house would do so.

Please feel free to contact me off line to discuss. The unit is out of its warranty so that should not be an issue.

Regards,

Paul.

[Ching_F.]

Hello Paul,

Unfortunately this is not something you can repair yourself.  It will need to be sent back to National Instruments for repair.

Please verify that your module is a revision G or earlier.  The link that Peter provided describes how to determine the revision of the module.

If it is not a revision G or earlier, please reply to this forum or contact your local Applications Engineering department for further troubleshooting assistance.