PXI MTBF

[Jerry_Whelan]

I plan to deploy 10 PXI-4472's in a PXI chassis with chassis controller where maintenance access will be difficult and expensive. I would like to identify the most reliable chassis and controller and gain some insight into the predicted failure rate of such a system.

What about the presence of the hard disk in the controller? Are there NI solid state replacements for this disk?

[Adam_U]

It sounds like you're going to need a chassis over 8 slots. In this case, I'd recommend the 14 or 18 slot chassis (1044 or 1045 respectively) as adding additional MXI extensions will add more expense and more components. For the controller, I would recommend a PXI-8196 for an embedded option or MXI-Express if you're hoping to stream back to a PC with fast hard drives. The PXI-819x series of controllers use the latest manufacturing and design improvements for increased performance and reliability.

For the hard drive, you can order solid-state but they are traditionally slower and much more expensive than the standard embedded controller hard drives. I would only recommend using it if you are going to put the system where it will experience vibration. If you do choose to use a SS HDD, you can have it installed through NI's Factory Installation Service (FIS).

[Jerry_Whelan]

Thanks, Adam. I looked at the MTBF for the 8184 RT controllers (listed at 226,000 hours), and the 8186 RT controllers (listed at 170,000 hours) and it looked sufficieintly high, even with a hard disk in place, but some of mgmt here is concerned about hard disk.... that's why I was asking. We will be deploying in a begnin environment for shock.

I could not find MTBF numbers for the PXI chassis with power supply. I wonder what the life is on moving parts like fans there. We have deployed five chassis with install times from 72 weeks down to 16 weeks, all OK except one controller smoked and got welded into the PXI chassis.... 🙂 I'm trying to find NI MTBF predictions for the chassis and 4472s, since they did publish one for the controller....

[Adam_U]

Though a HDD is one of the more likely components to fail, we often find that it is due to sudden shock or other physical events. To maximize uptime, you could always use the recovery CD provided with another laptop 2.5" HDD to create a backup in the event the first fails.

The MTBF for the current shipping revision of the 1045 is 57,751 hours at 25C.

[Adam_U]

Jerry,

I'd like to know more details about the controller you had that fused to the chassis. Please create a support request at www.ni.com/support and inform the PXI Engineer to contact the PXI PSE with the details.

Thanks,

-Adam

[Jerry_Whelan]

Adam -  Thanks for your interest.... I sent the chassis to Austin for repair, they elected to replace the chassis and controller, and returned that with all of our ADCs which were undamaged by the incident. We asked that they do a post mortem failure analysis and let us know what happened since it was (for us) such a spectacular failure.   Here is some information that you might find useful to find the story in your organization:

Entire system shipped to Austin on 17 Aug 2005, to Andrew Contreras, RMA #  RMA 708971 Order 1466960. Our contacts are: Austin - Debi Miers, inside sales rep,  Washington DC: Mark Lewis, local sales rep.

The repaired / replaced unit was returned to us three or four weeks later. As of last week Debi Miers said that there was no failure analysis data yet available.

That is the only failure we have experienced in any of our PXI gear, the rest continues to hum along most satisfactorily

[Adam_U]

Jerry,

That is the unit we are inspecting to see if we can use what we learn to improve our test coverage. I spoke with Debi about this issue and she conveyed what I said to you. We'll let you know once we know more.

Small world,

-Adam