Understanding EMC2 and feedback concepts

As this gets asked quite often from us, I drew a diagram of how the whole controller system looks (simplified) when making feedback system with EMC2 and VSD drives.

In some cases user wants to have dual feedback for maximized machine accuracy. Dual feedback is a system where there are two separate loops controlling machine:

• Inner loop, in this case motor velocity control within VSD drive and motor encoder
• Outer loop, in this case position control inside EMC and second encoder (linear encoder etc)

The same structure is present with single loop system (using only motor encoder).

I hope this helps :)

Awesome!

So - The drives can take +/-10 and pwm? How does the pwm work? (normally you would have pwm up / down or pwm + dir.) Do you only have one pin where the pwm is set so 50% duty cycle is 0 output?

I love that with your drives you have the option of getting away from step/dir.

sam