
The Keyence FS-V31CP is a compact digital fiber optic amplifier designed for high-precision photoelectric sensing and object detection in industrial automation environments. This main unit features an M8 connector interface and PNP output configuration, making it suitable for space-constrained installations. The amplifier utilizes a red 4-element LED light source with a wavelength of 640 nm and offers multiple response time modes ranging from 33 microseconds (HIGH SPEED) to 16 milliseconds (MEGA TURBO). It includes dual digital displays showing both preset and current values, a bar LED excess gain monitor, and switchable LIGHT-ON/DARK-ON output modes. The unit supports key lock function with PIN security, DSC (Dynamic Stability Control) for automatic threshold adjustment, and can connect up to 16 expansion units for multi-point sensing applications.
Item Details
- Brand Name: Keyence
- Manufacturer: Keyence Corporation
- Item Type Name: Digital Fiber Optic Amplifier
- Product Family / Series: FS-V30 Series
- Model Number: FS-V31CP
- Unit Type: Main Unit
- Output Type: PNP
- Connector Type: M8 Connector
Product Specifications
- light_source: Red 4-element LED, 640 nm wavelength
- output_configuration: 1 output + 1 input
- control_output: PNP open collector, 30 V DC, 100 mA max
- response_time: 33 µs (HIGH SPEED) / 250 µs (FINE) / 500 µs (TURBO) / 1 ms (SUPER TURBO) / 4 ms (ULTRA TURBO) / 16 ms (MEGA TURBO)
- power_supply_voltage: 12-24 V DC, Ripple (P-P) 10% max, Class2
- power_consumption_normal: 750 mW max (31 mA at 24 V, 40 mA at 12 V)
- power_consumption_power_saving: 580 mW max (24 mA at 24 V, 28 mA at 12 V)
- output_selection: LIGHT-ON / DARK-ON (switch-selectable)
- display_range: 0 to 64,512
- excess_gain_display: 0P to 999P
- control_input_functions: Calibration, scaling, zero shift, reset, light emission stop
- input_time: ON: 2 ms, OFF: 20 ms
- operating_temperature: -10 to +55 °C
- operating_humidity: 35 to 85% RH (no condensation)
- operating_ambient_luminance: Incandescent lamp: 20,000 lux max, Sunlight: 30,000 lux max
- shock_resistance: 500 m/s² in X, Y, and Z directions, 3 times respectively
- vibration_resistance: 10 to 55 Hz, double amplitude 1.5 mm, 2 hours each in X, Y and Z axis
- expansion_capability: Up to 16 sub units connectable
Additional Details
- Display Type: Dual 7-segment digital display (4-digit green LED for preset value, 4-digit red LED for current value), Bar LED monitor for excess gain (85% to 115% in 7 steps), Red LED operation indicator
- Special Functions: DSC (Dynamic Stability Control), Key lock with PIN number, Hold function (peak and bottom), Scaling display
Measurements
- Weight: 0.04 lbs (approximately 18 g)
- Dimensions: 30.3 mm (H) × 9.8 mm (W)
All PLC Direct products come with a 1-year warranty. The warranty is issued by PLC Direct. Warranty coverage commences at the date of purchase. The warranty is for mechanical defects or failures not caused by human factors including but not limited to (a) incorrect installation, (b) operating the unit in sub-optimal conditions or in scenarios not recommended by the manufacturer, (c) poor unit maintenance, etc. The warranty does not cover programming or software related issues.
If the product is eligible for PLC Direct’s warranty coverage and the customer encounters an issue with the product, we will request the item is shipped to us for diagnosis and examination. Regardless of the cause of product issues, the customer will bear responsibility for the cost of shipping the unit to PLC Direct for evaluation. Where the unit was damaged by human factors, we will offer a repair or replace quote; in cases where damage was caused by human factors, the customer is responsible for the cost of shipping the repaired/replaced unit from PLC Direct to the customer. Where the unit was not damaged by human factors but is covered by PLC Direct’s warranty, we will repair or replace the unit at our cost (or, in rare cases, refund you your purchase); in such cases, PLC Direct will bear the cost of shipping the repaired or replaced product back to the customer. It is up to PLC Direct’s discretion whether to repair, replace, or refund the customer in such cases. Diagnoses can take time to complete based on technician availability and the complexity of diagnosis.
In no event shall PLC Direct be liable for any damages except actual damages up to, but not exceeding, the amount paid to us for the product, including we shall not be liable for any consequential or indirect damages or lost profits whether or not advised of same.
PLC Direct offers free shipping worldwide. Product ship from a various warehouses worldwide based on the customer's and the product's location. The estimated delivery date on the product page is PLC Direct's best estimated assuming a US-based shipping destination.
Regardless of where the product is shipping from, PLC Direct covers all duties for US-based shipping destinations. For non-US-based shipping destinations, customers are responsible for duties as appropriate.
PLC Direct's focus is on balancing price with lead time. Some but not all products can be expedited. If you have questions about delivery ETAs, please contact our team.

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