motor ware 例程proj_lab01 故障设置·为什么设置成cbc 而不是单次？

void HAL_setupFaults(HAL_Handle handle)
{
  HAL_Obj *obj = (HAL_Obj *)handle;
  uint_least8_t cnt;

  // Configure Trip Mechanism for the Motor control software    配置触发·机制· 为什么周期触发？
  // -Cycle by cycle trip on CPU halt
  // -One shot fault trip zone
  // These trips need to be repeated for EPWM1 ,2 & 3      
  for(cnt=0;cnt<3;cnt++)
    {
      PWM_enableTripZoneSrc(obj->pwmHandle[cnt],PWM_TripZoneSrc_CycleByCycle_TZ6_NOT);

      PWM_enableTripZoneSrc(obj->pwmHandle[cnt],PWM_TripZoneSrc_CycleByCycle_TZ3_NOT);

      PWM_enableTripZoneSrc(obj->pwmHandle[cnt],PWM_TripZoneSrc_CycleByCycle_TZ2_NOT);

      // What do we want the OST/CBC events to do?
      // TZA events can force EPWMxA
      // TZB events can force EPWMxB

      PWM_setTripZoneState_TZA(obj->pwmHandle[cnt],PWM_TripZoneState_EPWM_Low);
      PWM_setTripZoneState_TZB(obj->pwmHandle[cnt],PWM_TripZoneState_EPWM_Low);
    }

  return;
} // end of HAL_setupFaults() function

故障设置·为什么设置成cbc 而不是单次？