getting encoder data from ni 7774

[harry-stone@idexx.com]

I am using the NI 7774 motion controller. I am new to labview and have one that someone else created. The data coming from the vi is rpm's, deceleration and acceleration and duration of test. What I also need is the encoder data. The motor I am testing has a connection from the encoder of the motor to the

NI 7774 motion controller. How do I get that encoder feedback data to show in my vi. I have attached the vi.

[Matt_McLaughlin]

Hello Harry,

The velocity is currently read in the while loop at the bottom of the block diagram with a function called Read Velocity.flx. To read the encoder position, you would want to use a very similar function called Read Position.flx. This function can be found in the Motion portion of the Functions Palette (Functions»Vision and Motion»NI 73xx»Trajectory Control»Read Position.flx).

The screenshots below show how the Read Position VI would be added.

Read Velocity:

Read Position:

I hope that helps!

[harry-stone@idexx.com]

This gives me the encoder postion but I still am having difficulty in getting the encoder position to a graph. I tried to wire to the existing graph but cannot get it to show the encoder position. Eventually, I need to graph this data in another program and need the encoder data to come out with the velocity data in the.csv file.

HS

[Thør]

You should be able to do something like the following to get both position and velocity to show up on the same graph:

Where Vel is what Velocity you had currently, and the Pos is the position data you can now obtain.  The arrays could be collected in a manner similar to what you had before.

I hope this helps point you in the right direction!