TMS320F28P659DK-Q1: Motor runaway when transitioning from ENC_ALIGNMENT → CALIBRATION_DONE

Part Number: TMS320F28P659DK-Q1

Tool/software:

Hi TI experts,

I'm working on "single_axis_servo_drive_fcl_qep_f28p65x" project.

For evaluation I chose LAUNCH-XL-F28P65X launchpad and DRV 8343S EVB.

my Question is similiar to TIDM-02007: TIDM-02007:motor start up problem - C2000 microcontrollers forum - C2000Tm︎ microcontrollers - TI E2E support forums thread.

 

I'm not using INDEX pin and so after alignment, I'm directly putting the motor in CALIBRATION_DONE (resetting the QEP at MAX position of encoder).

The problem is, often when the motor transitions from ENC_ALIGNMENT to CALIBRATION_DONE the motor goes out of control and rotates continuously and would not respond to any command., but the same code if I flash/restart multiple times it may work. but once it works it'll work fine till I reset or reflash. even multiple restarts will not hinder the performance. 

any insights would be helpful.

Thanks and Regards,

Raghu.