DRV8825: detect the step loss

Hi Team, 

Good day. I am posting this inquiry on behalf of the customer.

Please see the inquiry below.

"I want to integrate the drv8825 into our Hardware of the Horiba scientific.

But we should comparate it with the old drive, our old driver is the SMC11 from nanotech.
Can you tell me how we can detect the step loss in drv8825?"

Thank you for extending your help.

Kind regards, 

Marvin