Digital pulse on DO line
Hi, to output a digital pulse on one of the digital output lines instead of the counter, do i just select the particular line instead of the counter for the device?
And if i'm only generating one pulse, and idle state is low, then does it matter what i choose as my low time?
Finally, using the Digital output DAQmx, when I write high to a line, will that line stay high until the remainder of the program (or until i write it low)?
Thanks.
What type of DIO are you using? If using a standard DIO-96, you can use the Write to Digital Line function from the standard DIO functions. They are easier to use than DAQmx in this case. Just wire in the device number, channel number, line number, and True to output a high or False to output a low. Once a high is written to the line, it stays high until you write a low. The timing is up to you. You can write a high, wait some time, then write a low.
- tbob
Inventor of the WORM Global
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Just have a look at the picture.
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Hello��again
NOTHING seems to work for me, so here is another thing I´d like you friendly souls out there to help me with.
I have a small turbine (to measure breathing flow) that have a rotating range from 2 to 2500 rotations per minute. The rotor generates a digital puls every 180 degrees. To calculate the instantaneous flow I need to get the time between each puls. The digital puls is generated on ONE line from the sensor and I dont know if I´m supposed to plug this to a specific dig.line on my DAQ-1200 card in order to make it work.
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-Dawe-There is an example in LabVIEW that might help you out. It is called "Measure Hi Frequency (8253)". In this example it measures the frequency between two rising edges. The example description explains how to wire up this example. It uses two counters on your 1200.
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Hi,
I need to make a stepper motor undergo rotary oscillation with a sinusoidal motion profile. As it nears the extreme points it should decelerate and finally slow down to zero velocity and then it should reverse direction and accelerate until it reaches the other extremity where it should slow down and stop and reverse direction and repeat this motion.
The hardware is NI DAQ 6229 and the stepper motor can be controlled using digital Hi-Low (1,0) pulses. For each high pulse(1's) the motor turns 1 step. I am able to generate a analog sine wave and convert it to digital data using Analog-to-Digital.vi But i am not able to convert the digital data to a stream of 1's and 0's in the correct sequence to get the sinusoidal profile with the amplitude and frequency i require.
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Prabu.
Solved!
Go to Solution.Hi,
I finally figured out a way to do it. The analog sine wave is converted to digital and sampled. Consecutive values are compared and if the least significant bit(LSB) changes then a pulse is sent to the stepper motor to turn one step.
I have included the sub-VI's that accomplish it for the particular stepper motor and connector block i have. The front panel of both sub-VI's are quite messy but the block diagrams should be much clearer. The sub-VI's get their inputs from a third VI which i have not included. So take a look at the VI connector panel to figure it out. Hope this helps. Kinda messy but worked out fine in the end for my application.
Thanks again for all the help. I appreciate it very much.
Regards,
Prabu Sellappan
Graduate Student
Aerospace and Mechanical Enggineering
University of Southern California
Attachments:
start motor test waveform dtest.vi 73 KB
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