Agilent vs NI (PXI Chassis)

[Hamid]

Dear List Members,

My Boss has asked me to look into new Agilent PXI Chassis and compares it with NI Chassis.

The Agilent Salesman provides a list of "superior" performance items, such as:

- All slots are hybrid (not like NI that some of them are hybrid)

- two 4GB paths (effectively 8GB) for data transfer (as opposed to 2.5 GB for NI Chassis)

- Existing of Timing card? and Trigger line? that is more superior than NI?

- Better cooling methodology

- "Free" Agilent Test Exec Software module

I have not had a chance to test this Chassis yet and would like to ask independent opinion of the esteemed list members about their positive of negative experiences related to this new product from Agilent.

My main concern is lack of software (driver) compatibility with MAX and Labview, although the Agilent Sales man is assuring me that there is no such a problem! (Agilent is about 20-25 percent more expensive than NI)

Considering that Agilent does not have any FPGA, Image Acq, Motion Control, etc PXI Modules, it is a bit hard for me to accpet this claim. They provide a few DAQ and Switch PXI modules .

So, bottom line, if you are using Agilent PXI chassis, could you please share your impartial experience with me? Either positive or negative, please.

I really appreciate your help.

Kindest Regards

Dr. Hamid Yazdi

[jcarmody]

[...]

- Better cooling methodology

[...]

We have a few PXI-chassis-based ATEs and we have serious issues with cooling such that we often have to move test operations to cooler rooms in the summer. I'm not responsible for any of these operations, so my comments are only heresay (heresy ), but one of our Sr. Test Engineer has had several discussions with NI AEs regarding this.

YMMV, but I'm interested in what others say.

[Hamid]

It is interesting to hear that the "cooling" in 21st Century can be a problem! In fact this was a sales pitch of Agilent Salesman.

He said that you must leave a gap of at least 1U on top and 1U on bottom on NI-Chassis, whereas Agilent one will be perfectly fine without any gap, due to the superior cooling techniques!? I will be able to test this when I get a loaner Agilent on!

Cheers

Hamid

[Tim_S]

I've not had the opportunity to use PXI and am not very familiar with it, but...

- All slots are hybrid (not like NI that some of them are hybrid)

It seems to me this is only important if you mix the two frequently.

- two 4GB paths (effectively 8GB) for data transfer (as opposed to 2.5 GB for NI Chassis)

Assuming the speed claim is correct (can you reliably push 4 GB through traces in a real-world application? don't know), how big of a pipe do you need? It's nice to have a Formula1 engine under the hood, but if all you ever will use is a golf-cart worth...

- Better cooling methodology

I'm curious about this one. We leave at least 1U around rack-mount PCs, PLCs, UPS, etc., to allow air flow to occur. The only way I can see to avoid this would be to have forced air flow in the case.

- "Free" Agilent Test Exec Software module

Hrm... Is that the TestExec SL software? It doesn't look very free on the website. Then there is the adage of getting what you pay for...

[asbo]

It seems to me this is only important if you mix the two frequently.

This bit me recently - a PXIe chassis got ordered which has (I think) 3 PXIe slots and the other 5 are hybrid. The problem with PXIe cards is that they're more expensive and literally none of the hardware in this system needed the bandwidth of PXIe - there's one lonely thermocouple card that's PXIe for no good reason. In any case, a coworker went to add a PXI card to the chassis (in one of the PXIe-only slots, as it turns out) and couldn't figure out why Windows wasn't picking up his new card.

In my particular scenario, I think that the wrong chassis was ordered - which was a result of not enough thought going into what hardware was needed. I don't see a scenario where an all-hybrid chassis would be helpful unless you're going to be constantly reorganizing hardware.

[Hamid]

" I don't see a scenario where an all-hybrid chassis would be helpful unless you're going to be constantly reorganizing hardware. "

This is exactly the point. One may need to do exactly that.

This is the scenario, you are working on "validation" (and not end of line testing) of a product A.

You have a batch of x number of product A, you run your "validation" tests and provide the report back to Engineering Dept. and your job is done!

Now you have product B coming along for Validation. All you have to do is to swap (change) a few cards and load validation program for product B, and voila you have a system for testing product B DUTS. (In the mean time keep the program and the hardware for product A in a secure place! source safe for hardware!?)

Thanks

Hamid

Hrm... Is that the TestExec SL software? It doesn't look very free on the website. Then there is the adage of getting what you pay for...

My Bad, I asked about this in particular and you are right it is not free! I think it is about 2500 bucks!

By the way, do you know much about this TestExec? Apparently you can run Labview vi's too. Isn't this like Test Stand?

some kind of sequencer and scheduler?

Thanks

Hamid

[Tim_S]

" I don't see a scenario where an all-hybrid chassis would be helpful unless you're going to be constantly reorganizing hardware. "

This is exactly the point. One may need to do exactly that.

[snip]

You're looking for a tool rather than a dedicated system then.

My Bad, I asked about this in particular and you are right it is not free! I think it is about 2500 bucks!

[snip]

I just googled it to curious what they were offering. Can't say I've seen it before. There isn't much information, but it looks to compete with TestStand, which sells for $4000 for a development license, $530 for a deployment license.

[DavidMN]

Hi Hamid-

I believe we (National Instruments) have already contacted you offline but we would like to help clarify some of the original statements you posted that were provided to you by your Agilent sales rep.

1. bandwidth: The NI PXIe-1075 is capable of 4 GB/s of system bandwidth, not 2.5 GB/s.

2. timing performance: The phase noise of the PXIe-1075 TCXO, from which the 10 and 100 MHz backplane clocks are derived, is better than the one on the Agilent M9018A by 30 dB (1000x), when free running.

3. cooling: In order to achieve 42W of cooling for a single slot, the M9018A requires allowance of a 15 deg C temp rise for PXI module components as well as either 1U of rack space below chassis or that two air inlet modules be placed in two of the peripheral slots. The NI PXIe-1075 can cool 38.25W in all slots requiring the standard 10 deg C temp rise in module components and 1U of rack space above the chassis.

We want to keep this conversation objective and unbiased, so I am purposely not going to add any additional value statements or propositions. We simply felt that some of the original statements that were provided to you were either inaccurate or incomplete. I hope that this information is helpful to you and the participants on this thread.

Regards,

David Nosbusch

NI Product Manager - PXI Chassis

Edited December 19, 2011 by DavidMN