A nonservo electric slide typically uses ______ at the BOT and EOT positions to indicate to the PLC that the carriage is at one of its end stops.

A nonservo electric slide typically uses ______ at the BOT and EOT positions to indicate to the PLC that the carriage is at one of its end stops.

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

Answer: (B)

End stops need a simple, reliable signal to tell the PLC when the carriage has reached the end of travel. Limit switches placed at the bottom and top stops provide exactly that: when the carriage reaches a stop, an actuator on the switch is pressed, producing a clear on/off electrical signal that the PLC can read. This discrete feedback lets the controller stop motion, halt the drive, or establish a reference point precisely and quickly. Limit switches are rugged, cheap, and immune to a bit of dirt or vibration, which makes them a practical choice for end-stop sensing in a non-servo slide. Proximity sensors could work in some setups but require detecting a target and can be more sensitive to spacing and environment. Photoelectric sensors add optical alignment and dust/dirt considerations and aren't as straightforward for a fixed end-stop signal. Temperature sensors have no relation to position sensing.

End stops need a simple, reliable signal to tell the PLC when the carriage has reached the end of travel. Limit switches placed at the bottom and top stops provide exactly that: when the carriage reaches a stop, an actuator on the switch is pressed, producing a clear on/off electrical signal that the PLC can read. This discrete feedback lets the controller stop motion, halt the drive, or establish a reference point precisely and quickly. Limit switches are rugged, cheap, and immune to a bit of dirt or vibration, which makes them a practical choice for end-stop sensing in a non-servo slide.

Proximity sensors could work in some setups but require detecting a target and can be more sensitive to spacing and environment. Photoelectric sensors add optical alignment and dust/dirt considerations and aren't as straightforward for a fixed end-stop signal. Temperature sensors have no relation to position sensing.