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SCXI-1000 & USB

Hi.  I'm trying to read 32 Channels from a SCXI-1100 module that is in a SCXI-1000 Chassis.  The chassis is being read by a DAQCard-6036E... old PCIMCIA stuff!

 

Labview keeps throwing me errors that the maximum acquisition rate is 3.125KHz per channel.  I thought the was strange since the SCXI-1100  module was capable of much more (over 5KS/S/ch).  Then it dawned on me the the DAQCard is 200KS/S for 16 channels... and this would be 100KS/S for 32 in a mux which comes out to the magic number 3.125 KS/S/Ch.

 

Among other things, my problems are A) I am new to Labview & NI Hardware B) I am simulating this hardware C) I have never used a chassis with a mux output.

 

Can I "hook up" a -1000 Chassis to a USB device?  I have been searching NI for this information but have been unable to discern what data acquisition cards can be used with the SCXI-1000.

 

Thanks for any help you can provide!

 

terry

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Hi Terry,

 

I might need a little more information, but I think I understand your problem. If I understand correctly, you would like to avoid using an internal DAQ card and just go through USB for communication. The NI SCXI-1600 is a DAQ Module for the SCXI-1000 that allows it to work with USB, and it uses a USB A to B cable.

 

Let me know if I did not understand you correctly or you have any more questions.

 

Kind Regards,

 

Nathan Burke

Applications Engineer

National Instruments

 

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Thanks Nathan.  That might work.... does it replace the DAWCard6036E I currently have hooked up?  Would this be my "Chassis Controller"

 

-terry

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The SCXI-1600 is you DAQ device and controls the chassis, this communicates back to the PC via the USB lead.

 

Max sample rate using SCXI is 10K/S/s from any channel, for all 32 channels you could run it at 6250 samples per second per channel, in practice I would back this down to more like 5K/S/s - Mike

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Thanks Mike.  It sounds like the SCXI-1600 might be what I am looking for.

 

I tried to simulate this card in MAX but it was not an option -- is there a trick for doing this?

 

Thanks,

terry

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Hi Terry,

 

It should function very similarly a 6251 card, so i would suggest simulating that. In fact, that would leave you open to either the 1600 or the 6251 in terms of what you might like to purchase; they seem very different but both involve ways of communicating with a computer.

 

Let me know if that needs any more clarification.

 

Regards,

 

Nathan Burke

Applications Engineer

National Instruments

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A couple of points to consider when choosing between the SCXI-1600 DAQ or a PC based card.

 

Should you ever want to expand the system to use multiple chassis in the system you can daisy chain chassis from a PC DAQ card, multiple chassis with the SCXI-1600 would each require their own controller module. Due to this a multi chassis set up is cheaper using the PC based DAQ card.

 

1600 uses USB cable which is cheap, thin and flexible, a PC based card uses something known as an SH68 cable which is considerably thicker, less flexible and costs considerably more, depending upon the hardware sometimes you can lock the SH68 connector to the hardware sometimes it will not (I have examples of both) a 10M SH68 is another £180 to the cost of the system - Mike

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Hi Terry,

 

The SCXI-1600 is limited to an AI convert clock rate of 200 kS/s, so I don't think it will be an improvement over the DAQCard-6036E for your application. The mass termination versions of the USB-6251 and USB-6259 support SCXI, at the full SCXI maximum convert clock rate of 333 kS/s.

 

If you're planning on moving to 64-bit Windows in the future, be aware that the USB-6251 and USB-6259 are supported on 64-bit but the DAQCard and SCXI-1600 are not.

 

Brad

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Brad Keryan
NI R&D
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