An incremental output is a digital output device used to position a bi-directional electric motor.

• A. Pulse width modulation
• B. Incremental output
• C. Digital output
• D. Pseudopoint

Answer: (B)

Positioning a bidirectional motor with discrete steps relies on generating a controlled series of pulses. An incremental output is a digital output designed to produce those pulses in a defined sequence, so each pulse advances the motor by a fixed increment and the total position can be tracked by counting pulses. The direction can be changed by altering the pulse sequence or using a separate direction signal, enabling bidirectional movement. Pulse width modulation controls speed by varying the on-time of a signal rather than delivering discrete steps for position; a generic digital output lacks the stepping behavior and position-tracking capability unless paired with additional circuitry; the term 'pseudopoint' is not a recognized device in this context. Therefore, this option best matches a digital output device used to position a bi-directional electric motor through incremental steps.