Which type of sensor is commonly used as an end-of-travel sensor in nonservo traverse systems?

Which type of sensor is commonly used as an end-of-travel sensor in nonservo traverse systems?

• A. Limit switches
• B. Proximity sensors
• C. Photoelectric sensors
• D. Encoders

Answer: (A)

End-of-travel sensing in simple traverse systems needs a signal that is easy to implement, reliable, and provides a clear stop. Limit switches fit that role perfectly: they are mechanical contact devices placed at the travel endpoints, and when the moving part reaches an end, the switch is actuated to produce a definite on/off signal that tells the controller to halt motion. They’re inexpensive, rugged, and work well in harsh industrial environments, giving a precise and repeatable end point without requiring complex sensing or feedback loops. Proximity sensors and photoelectric sensors can detect objects or positions but require careful tuning and can be sensitive to alignment, dust, or ambient conditions, making them less ideal for a simple hard-stop end-of-travel signal. Encoders provide continuous position feedback and are more suited to closed-loop servo systems rather than a straightforward end-of-travel stop in a non-servo setup.

End-of-travel sensing in simple traverse systems needs a signal that is easy to implement, reliable, and provides a clear stop. Limit switches fit that role perfectly: they are mechanical contact devices placed at the travel endpoints, and when the moving part reaches an end, the switch is actuated to produce a definite on/off signal that tells the controller to halt motion. They’re inexpensive, rugged, and work well in harsh industrial environments, giving a precise and repeatable end point without requiring complex sensing or feedback loops. Proximity sensors and photoelectric sensors can detect objects or positions but require careful tuning and can be sensitive to alignment, dust, or ambient conditions, making them less ideal for a simple hard-stop end-of-travel signal. Encoders provide continuous position feedback and are more suited to closed-loop servo systems rather than a straightforward end-of-travel stop in a non-servo setup.