DAQ

[tocket]

I've just come to realize that a DAQ device is probably a very nice thing to have when you're working with lasers. The problem is that I don't really know much about them, so I'm not sure what to get.

I need both DAC and ADC, but not that many channels. I guess having a few extra doesn't hurt though. Resolution and sampling rate are more important though. I imagine 12-bit and 100 kS/s on both inputs and outputs will do.

The primary use of this DAQ is laser modulation characterization. I would like it to be sort of a mobile setup as well, so the interface should be USB or PC Card. I'd like it to work with LabVIEW or Matlab as well. I guess all NI DAQs do, but they're so damn expensive.

Anyone have any recommendations or thoughts?

[mixedgas]

Yeah, a old tube storage scope and a digital camera. preferably one by Tektronix, I'm partial to the TEK 76xx or 78XX series with 100 mhz plugins and the better timebase.

Available on Ebay, and at a decent cost too.

You must be really careful when buying DAQ gear, other then NI and Measurement Computing, you have to very, very careful.

One of the problems with DAQ, is that sellers seem to go out of their way to mix and match the IO to small combinations that force you to buy a lot of cards. ie 8 TTL lines is never enough etc , or you find that they are only adressable as byte

MIO16E by NI is good for A to D.

Beware of Labview, unless you can get a low cost student version. LV follows the micro$oft model, where they also own a publishing company besides a software/hardware company. Your always adding plugins and modules and paying for books for documentation. Its also bloatware. Sometimes the DAQ companies so poorly document the drivers in a attempt to force you to their prewritten applications that never quite do what you want. Often times its stupid, like displaying a 2048 bin FFT on a 256 x 300 window with smoothing, it took us two days and three different labview skilled people to find out how to pop the FFT box up to full screen etc,,,

That's a rant after 7 years of buying data aq for the department I worked in

Steve

[tocket]

As much as I'd love an oscilloscope, they seem rather hard to find here. My best bet is probably Germany, but considering their size shipping isn't cheap. If I buy one from the US, shipping is probably going to end up costing more than the scope itself. They are big, and I don't have a lot of space at home as I'm starting to realize now.

Besides, a scope only covers the input part. I need both input and output, which is why I find DAQ devices so attractive. I'm thinking something like this: http://sine.ni.com/nips/cds/view/p/lang/en/nid/203190

It probably costs $$$ though (I only get a 404 when I try to show the prices).

I don't plan to use it for digital I/O, so that's not really a concern now.

As for LabVIEW, I get it for free because my school has a site license. Sometimes being a student does have its advantages. That's why I like grad school, because you get paid (though less than in the industry) while still getting all these advantages.

Hmm... measurement computing is also OK you say... they seem a fair bit cheaper... something like this would also work for me I think: http://www.measurementcomputing.com/...413&pf_id=1757

[mixedgas]

They offered a student version of one of these in the US

like this: http://sine.ni.com/nips/cds/view/p/lang/en/nid/203190

came with a nearly full labview install and was about 180$, I remember buying it to get a laser doppler velocimeter off the high end labview card (signal was only a few hz to a few kilohertz) and other then the install taking forever and a few extra reboots, it worked quite good.

I've seen 16 bit 1 megasample a sec labview isa cards go on ebay for about 200$.


Ok, it was this one for 180 and shipping, with academic discount

http://sine.ni.com/nips/cds/view/p/lang/en/nid/14603
Steve

[tocket]

NI's student discounts aren't very generous. I also saw what the USB-6211 costs... a bit too steep for me.

Looks like I'll have to keep my eyes open for auctions and other second hand gear. Perhaps I can find something at my school that's about to get thrown away.

I installed LabVIEW to see what version it was and was happy to see that it is Pro, albeit an old one (8.2.1).