StanBon STG20-30NC Light Curtain Sensor - 30 Beams, 20mm Pitch, 580mm Height, NPN/PNP Output

The NPN output is an open-collector sinking output, commonly used with PLCs that require a current sink to common negative. The PNP output is a sourcing output, providing a positive voltage signal. Selection is typically made via a Jumper or DIP switch on the sensor's control box, and you must choose the mode that matches your control system's input type (sink or source).

The provided specifications focus on detection height (580mm) and beam configuration. The effective sensing distance, or the maximum gap between the transmitter and receiver units, is not listed but is a critical parameter. For safe operation, the transmitter and receiver must be aligned within the manufacturer's specified maximum range, typically several meters for such curtains. Consult the unit's manual for the exact rated distance.

Yes, light curtains like the STG20-30NC are often designed to interface with safety relays or programmable safety controllers that support daisy-chaining of multiple safety devices (e.g., E-stop buttons, safety mats). The configurable NPN/PNP outputs provide a switch signal that can be wired in series within a safety circuit to create a single safety loop, ensuring all devices must be in a safe state for machine operation.

Alignment is critical. After mechanical mounting, power both units and use the built-in alignment indicators (usually LEDs). Adjust the units until the 'Alignment OK' or similar status LED is steadily lit, indicating all beams are properly received. Some models feature a monitoring output (OSSD) that remains active only when alignment is correct. Avoid obstructions in the beam path and ensure the units are parallel.

The standard IP54 rating provides protection against dust ingress (level 5) and water splashes from any direction. The optional IP65 upgrade offers complete dust-tight protection (level 6) and protection against low-pressure water jets from any direction, making the sensor suitable for washdown environments, outdoor applications, or areas with significant dust or moisture exposure.