Get a FIRM grasp on supported DAQ cards. TOO many!!!

[asdfs]

We are doing some trial learning on a friend's system with version 8.0 pro.  I am concerned that it will not support any of the newer DAQ card out there.  I also am simple overwhelmed with the card count on the site.  Is there a flow chart or a master comparison chart of the different card and their abilities?  For now, we would be looking for rather basic functions for testing, but would later need something that can process pretty quickly and one app, we need to build an analyzer to trap frequencies and sample at around the 1Mhz range for short durations (2-10sec). 

I would certainly like to get a better grasp on whats hot, whats cheap and easy, what is not worth the time, etc.  Are there some publications here for that?  I realize NI can direct me if I tell them "exactly" what I need but the fact of the matter is, we will use this platform for many things in which one card could not fit all.  

I am also going to be very open to uses card in the short term because we are still in the learning phase.  I really do not want to throw several K at a card only to find out we really want something else.  I also want to gain some confidence in tuning before investing deeply. 

Our testing will mostly be temp, rpm, wave form analyze, compare wave timing offset from input to output, etc.  Later we will dip into PID stuff but that is beyond our level of skill right now.  

[tbob]

Talk to your local NI sales rep.  He can point you in the right direction, get you in touch with an application engineer who can recommend the right card for you based on your needs, and he could even arrange to loan you a card so you can evaluate it.

[asdfs]

Not to insult any consultants before visit but usually when I talk to a rep, they want to know "exactly" what I am doing, then recommend about 3 products, and here ya go.  I am trying to gain over all knowledge of the cards right now to understand say the difference in the PCI, PXI, PCI express, USB, etc as well as the model numbers if that can even be defined.  I really doubt apps engineers will be recommending anything but the brand new hotness and we most likely will be just fine to use  a used card for our applications. 

I very much agree though, that call could really help define some differences.  I was just hoping there was a flow sheet on that somewhere so I was not wasting anyone's time.  

[tbob]

Without help from NI, you will have to pour through all their documentation online for all the DAQ cards.  Just be up front with the sales guy and tell him that you don't want the latest and greatest, that you want something dirt cheap that will do thejob.  I guess it depends on the salesman.  He might be cooperative, and he might be a butt hole.  Doesn't hurt to ask.

Maybe if you give us your requirements, how many analog ins and outs you need, how many digitals, how many counters, then someone might be able to make a recommendation.  I've used the PXI-6225 in the past.  It has 80 AIs, 2AOs, and 24 DIOs.  There are certainly smaller cards for a cheaper price.

PXI cards require buying a PXI chassis and controller, or a PC with a MXI interface.  PCI cards can plug right into your PCs PCI slots.  There are USB based devices also.  The USB tends to be the cheapest (I think).

NI won't like this, but look at other vendors.  Geotest makes a good line of analog cards.

[asdfs]

Thanks.  We plan to use Labview for run things.  Let me know your thoughts on running other brands of cards on LV.  As I understand it LV has built in drivers for all their cards they are usually plug and play.  Now, I have no idea how much setup is really needed for others systems.  I am still feeling that one out. 

In short, we have about 5 projects on the block right now.  

Special design dynamometer with brake.  We will need up to 6 tach inputs (not sure on type yet), 3-4 inductive clamp inputs (scales voltage 0-10V), up to 3 load cells, 3-4 analog outputs, 5-6 thermal inputs (thermistor and possibly IR). This will be controlled closed loop to do sweep tests by programing sweeps to an output channel going to the load inducer.  Will also need to command set load rpms (example, induce load to set rpm at 4000rpm for 1 min,etc.)

Air flow system in which air volume will be controlled from LV to a variable motor control.  The volume and pressures of air will be recorded for analysis.  We will also need this in closed loop for sweep testing and to hold at certain pressures.  Ie, as we change a mechanical parameter of the tested device, we need the system to try to maintain a certain pressure and record the variable flow rates.  We are analyzing restriction. 

Next is a frequency delay analyzer.  We need to give a device a variable AC input in a sweep test and compare that to the device's AC output.  This will test from about 0-500hz.  The wave form and offset from input to output will need analyzed.  

We have not decided an any sensor methods just yet but you can see that most of our data in and out will be analog but we will want some digital ability for future apps.  All of the above systems will need dedicated installations where we will either build a dedicated computer to operate the system or simply plug in and test.  Reconnecting sensors, etc, will not be permissable so it is possible that we will need a card for every application here.  

It looks like USB might be pretty simple and cheap but I think latency and over all accuracy is a must with our tests.  maybe not medical level (example) but pretty darn accurate.  On the frequency analyzer, because we are actually measuring the delay, we will first (I am assuming here) plug the input and output directly together and generate a frequency and measure the offset.  That should tell us right there how much latency we have and might be able to just compensate for that and move on....

[AEI_JR]

asdfs,

NI regional reps are not salespeople, they are experienced engineers.  I have worked with quite a few, and they all have been knowledgeable and helpful.  They do not push the "new hotness", they listen to your needs and make appropriate suggestions.  Give them a chance before discounting them altogether.