Introduction

The DAPPRA DPR-2440-NPN-NC is a 24-beam Industrial Area Sensor and Safety Light Curtain designed for object detection, machine protection and personnel protection. This guide describes the recommended installation, alignment and wiring procedure for the sensor pair.

For full product specifications, visit the DPR-2440-NPN-NC product page.

Safety Precautions

• Disconnect power before mounting or wiring the sensor.
• Verify the machine risk assessment before final installation.
• Use a safety relay or safety controller where required by the application.
• Do not modify, disassemble or bypass the sensor.
• Ensure the transmitter and receiver are mechanically protected from impact.
• Maintain the specified safety distance from the machine hazard zone.

Package Contents

• 1 × Transmitter — Infrared beam transmitter
• 1 × Receiver — Infrared beam receiver
• 2 m connection cables — Pre-terminated cables
• M12 connection — Standard industrial connector
• Mounting accessories — Brackets and screws

Mounting Steps

1. Mark the mounting positions — Mark the mounting holes on both sides of the machine opening according to the CAD drawing.
2. Install the mounting brackets — Fix the brackets securely to the machine frame.
3. Mount the transmitter and receiver — Attach the transmitter and receiver to the brackets, facing each other.
4. Adjust the vertical position — Ensure the protection height covers the required machine opening.
5. Tighten all screws — Verify the mounting is secure and free from vibration.

Transmitter & Receiver Alignment

Correct alignment between the transmitter and receiver is essential for reliable multi-beam detection. The transmitter and receiver must be aligned across the complete 920 mm sensing height.

1. Loosen the mounting screws slightly — Allow small adjustments of the transmitter and receiver.
2. Power on the sensor — Apply DC24V ±20% supply voltage.
3. Check the alignment indicator — Verify the receiver detects all 24 beams.
4. Adjust the transmitter position — Move the transmitter until the alignment indicator shows a stable state.
5. Adjust the receiver position — Move the receiver until all beams are detected.
6. Tighten the mounting screws — Secure the transmitter and receiver without disturbing alignment.
7. Verify alignment — Confirm all 24 beams are correctly detected across the full 920 mm protection height.

Electrical Wiring

The DPR-2440-NPN-NC uses an NPN transistor output with Normally Closed (NC) signal logic.

For the specified NC configuration, normal beam transmission produces a 0V output and beam interruption results in no output. For complete product details, see the DPR-2440-NPN-NC product page.

Function Check & Test

1. Verify power supply — Confirm DC24V ±20% is applied correctly.
2. Check alignment — Confirm all 24 beams are detected across the full protection height.
3. Test beam interruption — Interrupt each beam with a test object and verify the output changes state.
4. Test the machine stop function — Verify the machine stops correctly when the sensor output changes.
5. Test the reset function — Verify the machine can only restart after the sensing field is clear.

Troubleshooting