GL-VM04LN 4-Beam 120mm Type 4 Safety Light Curtain

The Keyence GL-VM04LN is a Transmitter + Receiver set for industrial control and automation applications.

Keyence GL-VM04LN: Engineering-Grade Safety Light Curtain for Body Protection

The Keyence GL-VM04LN is a Type 4 safety light curtain transmitter and receiver set designed for body protection applications. It provides a 120 mm detection height across 4 beam axes with 40 mm spacing, operating from a 24 VDC supply with NPN transistor OSSD outputs.

This ESPE/AOPD pair uses optical synchronization and an infrared LED at 850 nm, removing the need for a physical sync line between transmitter and receiver. The minimum detectable object size is ø45 mm, and the detecting distance spans 0.3 to 15 m.

How Does This unit Achieve Type 4 Safety Integrity?

This unit meets IEC61496-1/-2 for Type 4 ESPE/AOPD and EN ISO13849-1 Category 4, PL e. It also conforms to IEC61508 SIL3, with UL60947-1, CSA C22.2 No.60947-1, and UL1998 listings. These ratings reflect engineering-grade precision in the safety architecture.

Response time for the OSSD channel 0, ON→OFF transition is max. 4.1 ms. The detection mode is ON when all beam axes are received, so any interruption in the protected field triggers a safe output state. Two NPN transistor outputs provide the control signal.

Electrical Specifications and Output Current

The supply voltage is 24 VDC -20/+25%, with ripple (P-P) 10% or less, Class 2. Maximum load current is 150 mA or less. Residual voltage (ON) is up to 2.5 V (5 m cable), and OFF voltage is up to 2.0 V (5 m cable). Leakage current is up to 0.8 mA, with a maximum load capacity of 0.8 µF and load wiring resistance up to 2.5 Ω.

Current consumption with indicator ON is max. 54 mA for the transmitter and max. 68 mA for the receiver, excluding OSSD output current. The input short-circuit current is approx. 3 mA. Protection circuits cover supply reverse-connection, per-output short-circuit, and surge.

Isolation and Environmental Resilience

While This unit does not specify a galvanic isolation rating in the source data, its protection circuits and EMC compliance (IEC/EN61496-1, EN55011 Class A, FCC Part15B Class A, ICES-003 Class A) support stable operation in industrial environments. The IP65/IP67 rating (IEC60529) ensures resistance to dust and water ingress.

Operating temperature ranges from -30 to +55 °C (no freezing), and storage temperature from -30 to +70 °C. Relative humidity can reach up to 95 % RH without condensation. The unit tolerates ambient light from incandescent lamps at 3,000 lux or less and sunlight at 20,000 lux or less.

Mechanical Construction and Installation Notes

The main unit uses aluminum alloy, with upper and lower cases in PPS (GF40%) and a front cover of polycarbonate and SUS304. Each unit weighs 120 g. The total length is 160 mm, and the effective angular aperture is up to ±2.5° at 3 m or above.

Vibration resistance is 5 to 150 Hz at 1G, 10 cycles each in X/Y/Z. Shock resistance is 15 G, 6 ms pulses, 100 times each in X/Y/Z. Interference prevention supports up to 2 units via series connection and switch setting. No built-in ports or communication expansion are provided, so integration relies on the hardwired OSSD outputs.

Applications and Maintenance

This unit suits body protection at machine openings, workcells, and automated stations. Its 4 beam axes and 40 mm spacing create a detection field 120 mm high. Periodic inspection should verify beam alignment, lens cleanliness, and output function. The aluminum alloy housing and IP65/IP67 rating reduce maintenance frequency in dusty or wet areas.

For precise matching to your safety circuit, contact AutoDCSTech with your exact requirements.