Does anyone have a LabVIEW coding file which can plot/read torque vs angular position ?

[Michael_78]

I have a system to do this and I know rotation is always the same way. I use a daq card and use the z pulse to start the acquisition and the encoder A output to trigger each measurement. This way I know that each pulse has exactly one torque value. It is a bit tricky to setup as you have toake sure the speed is within the daq acquisition rate. It is also necessary to set the timeouts correctly but once it is setup this gives excellent results. I am using M series PCI daq.

For higher shaft speeds I use timers on the daq to divide down the A pulse, that gets really fun!

[msi48]

May I have the code to look at? Many people suggest me great things here. I will share the code tomorrow. 

[altenbach]

---

@msi48 wrote:
I can measure torque vs time and angular velocity vs time. But I am not sure how I could measure torque vs angular position. 

---

Originally, you said "I can only plot torque vs time, angular position/speed vs time  as I am not good at LabVIEW.". You seem to be blending terms. Maybe you could clarify what you have, for example What is "angular position/speed"? How exactly does speed or velocity relate to position? Now you talk about "measure". Do you mean calculate from other known variables? Angular position relates to time via the speed, for example. Right?

We are still waiting for the CSV file that hopefully has all data to be plotted. As I already mentioned, we don't really need to go into any hardware discussion! It is irrelevant for the graphing of your data. You HAVE data, right?

Attach the CSV file, tell us what the columns mean, and we can write a LabVIEW program to do any desired graph in under a minute!

[msi48]

Hello,
In DAQExpress , I can measure torque(bridge vs time) from torque meter, and angular velocity/position vs time from encoder.
So I need to plot Torque (Y axis) vs Angular position/ velocity (X axis). I usded DAQAssist to get orque(bridge vs time) from torque meter, and angular velocity/position vs time plot. 

But I need to plot.
1. Torque vs angular position
2. Angular velocity vs angular position
I attached a similar code. 
For torque measurement, I selected bridge instead of voltage in DAQExpress and input a sensitivity value in micro voltage.

I hope I could edit the code but if anyone help me to edit the code, I will be glad.

[Minions]

Based upon your information this is what I gather:

1. Initial angle Input
   1. Without setting this properly, you will not be able to get your true angular position as you do not read the Z pulse from the encoder and continue the count of 360 degrees per revolution to 3600 pulses per revolution ==> Each pulse equates to 0.1 degree of angular position.
   2. When properly set, the angular position can be derived from the sample number and the sample rate.
   3. Using a relative position rather than absolute.
2. If the angular position is usable, then you can plot the array of Torque against the derived angular position.  Option 'C' will not provide repeatable results over multiple instances of this code if used to detect a system anomaly.

[msi48]

Can anyone help me to synchronized the time, start/stop?
I attached the code. I will appreciate it if anyone can edit he code.
Thank you 

[LVNinja]

can you save for lv version 2020 ? 

[msi48]

Here it is.