Producing a step function out of a DAQ 6009

[JakePlaysDrums]

Hello,

I am trying to produce a signal from my DAQ USB-6009.

This signal will be outputed from the DAQ, to a linear actuator, to deliver a force. The linear actuator has a force sensor, to provide feedback to the DAQ.

The step function I am trying to produce is visualised in the graph below:

Y-axis (voltage in volts), X-axis (time in seconds)

+3 |                       --------- 

+2 |             

+1 |        ------------- 

  0 |  -----                          -------------------------

      0s   1s           5s       7s                         10s

Questions: 

1. How would I go about producing this signal from Labview to the DAQ to the linear actuator?

2. How would I incorperate a PID controler. 

3. How would I write onto the DAQ from the force sensor?

I have attached a picture of what I have accomplished so far, but I am recieving errors from the DAQ reader. I am willing to scrap this VI and start from scratch if that would make it easier. 

Thanks

[GerdW]

Hi Jake,

using Control&Simulation loops is likely overkill for this problem…

1. How would I go about producing this signal from Labview to the DAQ to the linear actuator?

I suggest a simple FOR loop: set a voltage and wait the delay. In the next iteration do the same. Your example translates to "coordinates" (voltage/delay pairs): (0V, 1s), (1V, 4s), (3V, 2s), (0V, 3s). Put those into an array, the FOR loop will autoindex them…

2. How would I incorperate a PID controler. 

Use the PID function found in recent LabVIEW versions. It comes with example VI, so study them!

3. How would I write onto the DAQ from the force sensor?

Use an analog input of your USB6009 to read the force sensor signal…

LabVIEW and DAQmx come with a lot of example VIs. Study them!

[JakePlaysDrums]

Thanks for the reply.

Could you please claify "voltage/delay pairs".

I am a novice user at LabVIEW, any step by step explaination would be helpful. 

[GerdW]

Hi Jake,

Could you please claify "voltage/delay pairs".

You want to output a certain voltage for a predefined time: So you have to define a pair of values, one voltage value with one time/delay value…

See this simplified example:

You can also use a 2D array instead of 2 1D arrays…

Btw. you know how to produce "screenshots"? 😄 (Or is your LabVIEW computer not connected to the internet?)

[JakePlaysDrums]

Thanks for the reply.

I was just responding to you on my mac laptop, and it was easier for me to take a picture with my phone and send it there rather than screen shot it from the windows one, haha.

Thanks