motor control

[NU-MA]

Hi,

I am using Labview 8.2 with DAQ-6062E. I have a linear actuator and a 15 amp bidirectional digital PWM motor speed controller (from critical velocity, inc). Also, I have a linear potentiometer for position measurements.

I would like to control the actuator through labview that

            a) starts and stops at certain positions

            b) after stops at a certain position, waits for sometime (few seconds) and then reverse direction.

            c) and I would be able to control the actuator for different speeds.

Could I use the system I have to do the motor control? And is there any example? Do I need to use motion control toolkit?

Thanks,

Azadeh

[Brian_Beal]

It appears that you have what you need, other than the power supply.  That motor controller accepts a 0-5V signal for speed control.

[jaced]

Hi Azadeh,

I see no issue with using your hardware to complete this task without the need of an additional toolkit. This application will be software timed therefore more of a fuzzy logic system than a deterministic system, meaning that your timing may vary due to its dependence on the operating system. I would use an analog output to control the position and either an analog output or a digital line to control the direction. Concerning examples, this program in essence will be an analog input that determines the values of analog outputs. The examples that I would use are Gen Voltage Update.vi for the output and Cont Acq&Graph Voltage-Int Clk.vi for the input. Both of these examples can be found by selecting Help>>Find examples>>Hardware Input and Output>> DAQmx and either Analog Generation or Measurement followed by Voltage for each. I hope this information helps please post back if you have any further questions.

[NU-MA]

Thanks for the reply.  I was able to control the speed of the motor through the program. I have attached my vi. (right now, I am not using the position sensor). By clicking the “motor reverse” button, the motor is reversing. However, I would like after I press the button, the motor stops for 5 seconds and then starts. I tried to send out 0 voltage to analog out after the “motor reverse button” is clicked but I was not successful. Any suggestion?

Thanks,

A

[jaced]

Hi Azadeh,

I’m glad to hear that progress is being made. I believe that I have the basic logic that you should use figured out. Below is a screenshot ( with both cases shown) of the logic that I implemented to achieve a 5 second wait at every change in Boolean value. So this case structure would operate off of your directional control and contain the values that you wish to write to the analog output.  Please post back if you have any questions.

Message Edited by jaced on 11-07-2007 03:15 PM

[NU-MA]

Thanks a lot Jace. It worked, now I am adding the position sensor to the loop. If I find a problem, will post back again.