Stepper Control

Hi all .
I am looking for some help and here is a simplified version of my project. I have a motor and 2 steppers that I am trying to control. The motor rests on a table whose position is defined stepper 1 and stepper 2. My main problem is with the positioning sequence. States A through E represent different positions i would like to 'fire' at.   Position A is the resting position and the motor is always in the 'on' state. At regular intervals ( 5 minutes ) or on demand ( 'press fire') a 'firing' event is triggered. Whenever this happens I would like for the motor to stop and then the table to move from A to B and then back to A. When prompted the second time the motor stops and the table moves from A to C and back to A and so forth. The cluster provided in the 'fire' event case are coordinates to the new position. The order of movement is something like this:
First Time    ( 5mins)    =      A to B
Second Time(10 mins) =      A to C
Third Time    (15 mins) =      A to D
Fourth Time (20 mins) =      A to E
Fifth Time    (25mins) =      A to B
The motor is also turned on after reaching the new position. I would like to know how to implement this sequence. As it stands the table moves continuously in an almost random manner which is not what I want. Thank you in advance.
Attachments:
state machine.vi ‏33 KB

Charles.m,
I am not sure I completely understand what you are trying to do. Your simplified example is almost too simple.
I suspect that your problem is in the shift register and event structure in the upper loop. You have the output tunnel set to "Use Default if Unwired." Everytime any event case with that terminal unwired executees the value on the shift register is set to the default value for the enum, which appears to be "A." When I wired through all the other cases and alternately hit the Fire and Start Motor buttons, it seems to go through the sequence you want.
Use Default if Unwired is useful for situations like the booleans connected to the termination terminal for the loop. Only in the Stop case do you wire anything. In most other circumstances, like tracking the position (A B C D), it is definitely NOT what you want.
Lynn

Similar Messages

Stepper control with labview

Hello again,
Im developing a project with a lazer pointer attached to a stepper motor, my program allows me enter a value and make the stepper "step" a certain amount of times .This works ok but I have to stop the program running and start again in order to make the stepper step again.Is there a way that I can enter a value to make the motor rotate then enter another value to make it rotate again without stopping and starting the program. Ive attached my vi
any input is much appreciated
Attachments:
jonnystepper.vi ‏133 KB

Thanks!!
Right here goes, the array in the while loop defines the sequence for half step mode, this array contains 48 values and therefore if all the elements are read this gives 48 (half) steps which corrosponds to 90 degrees of rotation (the motor gives 3.75 degrees per full step). The for loop part of the vi allows me to enter a value in to the control named index 2, the array in this part of the vi contains values that corrospond to a particular number of half steps.So if I have 48 in the first element and 24 in the second element this allows 90 and 45 degrees respectively, if 0 (first element) is entered into index 2 the for loop iterates 48 times and therefore I get 90 dgrees of rotation,if 1 (second element) is entered into index 2 then the for loop iterates 24 times and I get 45 degrees of rotation. What i would like to achieve is .......enter 0 into index 2 then start the program, when the motor has finished rotating I would like to change the value in index 2 to1 and see the motor spin again without having to start and stop the program.
Apologies for explanation........I hope you can understand the jist...please feel free to tell me if you think my method is incorrect or contrived
with freunlichen Grüss

Best value stepper control solution

Hi,
I'm currently working on a university project to build a 2-axis traverse for our wind tunnel. We are going to be using stepper motors for the movement and controlling them through LabVIEW. I've been looking at motion controllers but have to admit I'm a bit confused about a few things. So far I've come up with two possible options but am unsure of the accessories I will need to achieve the functionality I require. Here are the options:
1. PCI-7334 4-axis stepper controller (4-axis card instead of 2-axis so that a third axis of movement can be added at a later date)
2. NI-9512 CompactRIO module x2
I want to be able to control 2 NEMA-23 motors with quadrature encoder feedback using either P75030 or P70360 power drives. The main thing I'm confused about is whether I would need to buy the NI-UMI-7774 and/or NI-UMI-7764 for this or if the encoder and stepper drives could connect directly to the PCI card. Also are there any connectivity accessories that would be required for the NI-9512 or does everything here connect directly to the module.
Thanks in advance for any help,
Adam
Solved!
Go to Solution.

Hi Adam,
The two options of PCI-7334 and NI-9512 will both be suitable for controlling NEMA 23 stepper motors.
I have found a few documents which will detail what you need for each of these options.
PCI-7334 - http://www.ni.com/pdf/manuals/372324d.pdf
NI9512 - http://www.ni.com/pdf/manuals/375578a.pdf
For more information on what comes with each module and the current pricing i would advise contacting our sales team for a more in depth discussion with you so that you get the best setup for your needs.
If you are based in the UK or Ireland then you can call 01635 523545.
Please post back if you have any further questions.
Best Regards,
Ben B.
Applications Engineer
National Instruments UK & Ireland
"I've looked into the reset button, the science is impossible!"

Stepper Control with labjack

Hi everybody,
Im doing a project at uni that requires me to control a small stepper with labview. The program I developed can generate the correct binary sequence (using a 4 element array) but the problem im having is obtaining a high enough frequency to drive the motor at sufficient speed. Two pieces of hardware that ive tried to use are Labjack and NI ELVIS(to output the signals). I now Have access to NI DAQPad-6015.

What frequency range do you need?
Using discrete digital outputs toggling on/off, you will be limited by the iteration speed of your software loop. This is probably limited to 100's of Herzt, most likely less than 1KHz. Post your code, maybe we can help. Please note that software timing can be indeterminate due to Windoze overhead- the speed of your motor may not be constant. Also note that your stepper may stall out if you command it to accelerate too fast.
The other option is that the DAQPad-6015 has 2 counter/timers that you can use to generate a wide range of frequencies and dynamically change and ramp up and down in frequency. But you would also need additional simple hardware (state decoder) to generate the 4 discrete phase signals that go to the motor drive electronics.
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"It’s the questions that drive us.”
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Easy driver stepper control via digital outputs

Hi, I have a couple little motors that I'm driving with a Sparkfun easy driver board. The board just takes in pulses, and for each pulse it gets it steps the motor one step. Another digital pin sets the direction. I have attached the VI.
I have the digital PFI1 on my DAQ connected to the "pulse" terminal on the board, and it steps when you send pulses to the board. However, the DAQ seems to be operating in burst mode. If I set the frequency to 10 Hz, for instance, with a finite number of steps (say, 1000), the motor steps in little bursts rather than continuously moving. I scoped the output of the DAQ, and it does appear to be turning the square wave on and off.
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Attachments:
Stepper2.vi ‏51 KB

Hm. It appears that Sparkfun has a number of defective units that behave this way. I think my code is actually fine.

Using LabView, Arduino, and Easy-Driver to control a Stepper Motor

Hello fair folks of the LabView forums!
I am a humble engineering student in need of some advice and input on a project I am working on.
I’ve also done a fair amount of reading on the LabView forums with people trying to use LabView and Arduino to control stepper motors, and I’ve used as much information from each as I could. However the problem I'm encountering now is one which is unique to my VI Configuration.
So, here is what has been done thus far:
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But here is general problem I am encountering:
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I know that in the example code, the Arduino issued the step command by writing the signal from LOW to HIGH, and varied the speed by how often it did this.
I assumed that the Write-PWM feature would do this same thing, but perhaps my assumption is wrong. I will continue to tinker with this myself, but I would be extremely grateful for any insight you might be able to lend.
I’m thinking, if not the Arduino Write-PMW feature perhaps a simple timing-sequence that could be used to alternate between writing 0 and 1, with the timescale of the sequence being scaled to the X-Axis from the Joystick. But, I am open to suggestions, and certainly appreciate any thoughts you may have to offer!
Attached to this is the VI used in this setup, a picture of said VI, as well as a rough sketch of the hardware configuration.
Thank you!
Attachments:
Arduino Stepper Control.vi ‏1224 KB
VI Picture.png ‏82 KB
Configuration Sketch.png ‏522 KB

Hi danjifraga,
I am not so familiar with the Arduino toolkit functions, but you may have better luck looking at the Arduino page at:
www.ni.com/arduino
I'll ask around on Monday to see if anyone is more familiar with the toolkit.
Good luck,
Brian
Brian G.

Control a stepper

Hi,
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The pulses come from the counter of the connector block.
I have a worse resolution (attachment) where this funktion works.But every time the while-loop starts I have a short break in the funktion and this
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Attachments:
Stepper-control.JPG ‏57 KB

See the attached, it is a simple program showing a continious update of a pulsetrain out of "dev1/ctr0". Hope this helps.
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Attachments:
UpdateCounterFrequency.vi ‏53 KB

Stepper Pulse Voltage Level in Open Collector

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Choe.
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How can I use flex motion control VI without hardware?

I would like to try and simulate the motion control of my system before i hook up the motion control card. But when I use the VI in flex motion contro took kit it asks for address or something and gives me an error. Can't I just simulate without hardware?

Hello,
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Regards,
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What are resources that one has to use motion control in LabView?

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Thanks for the response.
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Attachments:
E4P%20Data%20Sheet.pdf ‏89 KB
21000.pdf ‏446 KB
HaydHybridDrivers.pdf ‏383 KB

Hi Brian,
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Sincerely,
Christian
Message Edited by aufgeschlossen on 04-10-2007 09:00 AM
Message Edited by aufgeschlossen on 04-10-2007 09:00 AM

Stundent Project- Remote Controlled Microphone Stand

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Mish,
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Whether the NI step controller can control the digital servo driver and motor

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Best regards

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Stefano,
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Stepper Control

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