AnalogKid2DigitalMan
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Posts posted by AnalogKid2DigitalMan
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God:
Are you a multi-threaded infinite state machine using global variables? Did you send us THE Notifier?
-AK2DM
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Well, there's a quick way to check with an ohmmeter- one lead to USB or DAQ ground and the other lead to the AC socket ground. But I bet they are isolated from one another.
-AK2DM
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Classics!
Whenever one of my LabVIEW programs is running and the block diagram is showing I make sure to keep the mouse cursor from touching any wires. As an added precaution, I keep one hand behind my back at all times and remove any jewelry.
-AK2DM
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Sweet mechanisms.
Here is a true atomic reference wristwatch, I don't think a ladies version is in the works, though.
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Cross-posted on the dark side at:
Hello All:
Questions and guidance regarding chrome-on-fused silica targets used to calibrate vision systems:
We have a couple of these at our facilities and in order to satisfy ISO requirements, some people internally insist these must be sent out yearly to be ‘calibrated’ (re-certified is probably a better term). Since they are not subject to wear akin to rulers, scales, pin/plug gauges, I see no need to have this done. They are a pattern of squares and circles of various sizes, typically ranging from 0.0005” to 0.5” and have been measured at the time of manufacture to within +/-.00001” and 0.00002” uncertainty. Coefficient of expansion is a negligible 0.5ppm/C. Unfortunately, the companies that fabricated and measured the standards (P.P.L/Align-Rite and Optronics Specialty) have moved on to other lines of work and I cannot get a statement from them to back up my position. The last time we sent one out, it almost was lost in transit and then took 3 months to get it back.
Anyone else have experience with such matters and how did you handle it?
Other than NIST, any suggestions of companies that can certify such standards since I would like to get a tighter uncertainty measurement on one of the standards.
Thanks for your feedback!
-AK2DM
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Eugen:
About 7 years ago I used an Elo Touchscreen for use in a LabVIEW application I wrote. It connected to a serial port, had to install a driver, and calibrate the screen. It worked just like a mouse but no right click feature, and operators could still use the mouse as a standby. It was not practical to program in LabVIEW though.
By now they probabbly have USB interfaces and some more features to emulate mice with more features, I presume.
Not familiar with NI Touchpanels, paying for a liscense does seem a bit odd.
-AK2DM
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And if you use a coil type relay, make sure to use a reverse biased diode (ie 1N4001) right across the coil to protect the DAQ from the back EMF when the relay is switched off.
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In addition to slug bugs, we also watch for sting stangs (Mustangs) and cruiser bruisers (PT Cruisers). There's alot of hitting going on, needless to say.
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To reset files to current date/time you can use a get file size followed with a set file size (wire the size in bytes together), if that helps any.
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I wrote the LV code to verify the diameters of the various layers in the optical fibers in real-time while we were drawing them, over a million meters are in used in the Compact Muon Solenoid. I hope it works!
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I tried listening to the Playboy channel via audio stream while coding but found that my BD's kept growing larger than the size of my screen, thus I abandoned that practice.
Actually I just listen to whatever comes up on the MP3 player- lots of
Rush, Tool, Zappa, Floyd, Tom Petty, Yes, David Bowie, David Gilmour, Peter Gabriel, REM......... -
QUOTE (Dan Bookwalter @ Aug 7 2008, 06:08 AM)
Timone thing i need to make clear is that i am not trying to control the shaker with the card , just take some data off of our devices on test... as far as the cables are concerned they are shielded twisted pair with the shileds connectd to ground at one end. I have always been a firm believer in single point grounds hence the reason i have tied everything together at one point. I can try connecting both ends to ground once to see what happens. also i am not sure i made it clear that the noise appears only after i enable the modules on the amplifier , just powering up the amp doesnt generate any noise.
Dan
The amplifier is a Voice Coil Driver , the 480V is not in metal conduit , but , i dont think that is where the problem lies... the noise is only present after i enable the amp modules , just turning the amplifier on does not induce any noise...
yep have several scopes here....
Dan
Dan:
Can you scope out the frequency content of the noise near the DAQ and then trace higher amplitude back upstream towards the amp? Appears like amp enable makes the drive amps the culprit- what's the make/model. Sounds like you have a good handle on grounding and wiring practices, these things can be a bear since it could be conductive, capacitive coupled, or radiated induced noise. Have you tried moving the amp ground somewhere else and is it an option to safely run it ungrounded as a test? Even with a system schematic and pics it is hard to guess what the issue might be without being on-site.
-AK2DM
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What technology is the amplifier based on (i.e VFD, servo, voice coil driver)?
Are the 480V lines in steel conduit?
Do you have access to an oscilloscope?
Sorry for more queries.
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LV 8.6 Known Issues (so soon?)
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They opened fine in 8.2, looks pretty straighforward to control.
Thanks for the link to the manufacturer, I'll have to keep their in my fav's for future reference.
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New book with projects for the NXT:
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Inputs with open circuits are expected to float and drift around, sometimes pegging at the +/- rails. Try connecting a battery or shorting the input leads on a channel together. You should read the battery voltage, and with a shorted input you should read 0 volts.
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You may need to condition your signal if using a TTL digital or counter input. 1.8V level is sort of a gray area between where a logic low and high is defined. Suggest you look at the specs of your DAQ card to see if 1.8V will qualify as a logic low.
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Micheal:
Nice goat! You kinda look like Harold Shrinks from the PBS George Shrinks show (it would make a nice avatar for you)
http://pbskids.org/georgeshrinks/caregiver/index.html
Keep up the good work! No NI Week for me this year.
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Pool has ben dug, now it is filling with water.
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Yair:
I finally had a chance to view it a few times while my son trashed the living room in a matter of minutes at home (no access from work).
Didn't look up the source nor the context, and I'm definitely not a film critic. Here are my observations and interpretations, not necessarily my beliefs or opinions.
Good imagery and foreshadowing, appealing music though I don't know the translation. At the end I interpolated "Shine my shoes, then I die, they are done"
Glowing temple or crypt transitioning to a street light illuminated, shade wearing, 4 fingered?, hawker (akin to Morpheus and Neo choosing between the red or the blue), control and choice is an illusion.
Suit goat guy initally reaches for the smaller card then takes bigger one instead.
Whale shapes in the clouds, water ripples in sky, bird shape in mountains transition to a bird flying. More whales between the trees (cool effect).
Donkey kicks off suit goat guy after he looks back possibly questioning his choice. Why does he taste the dirt?
X marks the spot? Not really, it is actually a cross. Looks like LAVA down there too
Suit goat guy dresses up for the final leap. Goat eyes are so cool.
Climbs back out of the hole as a small donkey with a shred of a tie on. Has lots to learn possibly, confirmed with a nod to the much larger donkey. Didn't Jesus ride on a Donkey?
The other goat guy, I have no idea. Goats are cool.
Some are blessed and some are cursed... (Rush- The Larger Bowl)
Thanks Yair, you sucked me in, at least not into the 5th Dimentia. :thumbup:
-AK2DM
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Diodes only pass current in one direction (though there is a slight leakage current when they are reverse biased). And they also exhibit a voltage drop when forward biased, the drop depends on the semiconductor materials used in their construction (typically .3 to .7V).
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In order to be able to switch between NI-DAQmx and NI-DAQmx Base, you must have both the NI-DAQmx and NI-DAQmx Base drivers installed on the PC. More specifically, you must have these versions of the DAQ drivers:
NI-DAQmx Base 1.4 or later
NI-DAQmx 7.5 or later
If you do not have these drivers you will need to install both of them to switch your firmware. See current drivers linked below to download the latest version(s).
Above is from last paragraph of this link to resolve issue:
http://digital.ni.com/public.nsf/websearch...10?OpenDocument
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QUOTE (neB @ Jun 6 2008, 12:33 PM)
Ben:
You suckered me in with apod in the link. Have any of Oh Henry on Little Debbie? Asteriods around Uranus? On second thought, please ignore that
My First Labview... Help everyone!
in Hardware
Posted
All that circuit does is provide electrical isolation to an existing serial port.