Dual encoder feedback on single axis implementation

[ilnus]

I have reel-to-reel transport system connected to a NI 9516 module in one axis. It has two servo motors and two encoders. One encoder is on the motor, while the other is on the linear portion of the reel. Both encoders and the feeder motor are connected to the 9516. The Take-up motor is just set to contant torque. Since I want the ribbon to travel at a constant linear velocity, I have set the primary feedback to the encoder on linear portion, with dual encoder feedback enabled. Is this a proper utilization of the dual feedback mode, with one encoder monitoring linear velocity, while the other is monitoring rotational velocity?

Linus

[LVbum42]

Hello Linus,

I think the setup that you've shown would work, generally the secondary feedback is used for backlash but you should be able to use the secondary encoder to monitor rotational velocity.

Dual Loop Feedback Information and Configuration