Product Description

The Keyence FS-V21 is a compact and versatile digital fiber optic amplifier designed for precise detection in industrial automation applications. It features a red LED light source and offers selectable response times ranging from 50 µs (High Speed) to 4 ms (Ultra Turbo), accommodating various detection needs. The amplifier includes a shift function with a range of ±1,999 and supports multiple timer modes, including OFF, OFF-delay, ON-delay, and one-shot timers, with durations from 1 to 500 ms. Its NPN open-collector output can handle up to 100 mA with a residual voltage of 1 V max. The FS-V21 operates on a 12 to 24 VDC power supply and offers low power consumption, making it suitable for energy-efficient applications. Housed in a durable polycarbonate case, it is engineered to withstand environmental challenges, offering protection against reversed polarity, overcurrent, and surge conditions. Its robust design ensures reliable performance in demanding industrial settings.​

Technical Specifications

• Model: FS-V21
• Type: Main unit with cable
• Light Source: Red LED
• Response Time:
• 50 µs (High Speed)
• 250 µs (Fine)
• 500 µs (Turbo)
• 1 ms (Super Turbo)
• 4 ms (Ultra Turbo)
• 500 µs (High Resolution)
• Shift Function: ±1,999 (variable)
• Timer Functions:
• OFF-delay timer
• ON-delay timer
• One-shot timer
• Selectable timer duration from 1 to 500 ms
• Control Output: NPN open-collector, 100 mA max. (40 VDC max.), Residual voltage: 1 V max.
• Power Supply Voltage: 12 to 24 VDC ±10%, Ripple (P-P) 10% or less
• Power Consumption:
• Normal:
• S-APC OFF: 580 mW
• S-APC ON or High Speed mode: 720 mW
• ECO half:
• S-APC OFF: 480 mW
• S-APC ON or High Speed mode: 600 mW
• ECO all:
• S-APC OFF: 430 mW
• S-APC ON or High Speed mode: 550 mW
• Environmental Resistance:
• Ambient Light:
• Incandescent lamp: 20,000 lux max.
• Sunlight: 30,000 lux max.
• Ambient Temperature: -10 to +55°C (No freezing)
• Relative Humidity: 35 to 85% RH (No condensation)
• Vibration Resistance: 10 to 55 Hz, Double amplitude 1.5 mm, 2 hours in each of the X, Y, and Z directions
• Shock Resistance: 500 m/s², 3 times in each of the X, Y, and Z directions
• Case Material: Polycarbonate
• Size: 30 mm (H) x 9 mm (W) x 70 mm (D)
• Weight: Approx. 80 g (including 2-m cable)