Industrial Automation and Control

A: A. This would create speed jitter and angle noise that the speed loop would chase, not a clean speed with torque sag. B. This pushes current ripple and audible noise, usually visible as bus alarms before torque collapses. C. This causes immediate direction or speed errors and the drive won’t hold speed at all. D. This biases the observer so torque estimate drifts under load while the speed loop still closes cleanly.

A: A. That assumes an execution model closer to FPGA logic and ignores task context switching. B. That treats preemption as blocking the whole cycle rather than time-sliced scheduling. C. That’s a drop-the-units mistake that ignores typical instruction timing by two orders of magnitude. D. Multiplying instruction count by execution time and adding scheduler overhead lands you near a millisecond.

A: A. Regeneration is already blocked once gate firing is inhibited so this effect is secondary. B. Hazardous voltage presence is a separate function like Safe Stop 1 or Safe Power Off. C. Gravity-induced motion is a classic gap but usually addressed with brakes or SS1. D. STO only disables drive-produced torque and says nothing about externally applied torque.

A: A. That interpretation would invert the de-energize-to-trip philosophy. B. Dashed lines usually show mechanical linkage, not PLC logic. C. The legend clarifies tagging but the contact state is explicit in the symbol. D. The closed-at-rest depiction matches loss-of-energy-to-safe behavior.