The Keyence FS-N42N belongs to the FS-N40 series of digital fiber optic sensor amplifiers. This expansion unit carries an NPN output and a clear OLED display for easy setup. Engineers choose the FS-N42N for fast, stable detection in tight spaces. Meanwhile, the 23 µs response time supports high-speed sorting and positioning tasks.
The amplifier uses a red four-element LED with a 660 nm wavelength. This light source gives strong, consistent emission for reliable fiber sensing. FS-N42N offers eight response modes, from 23 µs (S-HSPD) up to 64 ms (TERA). Therefore, users can balance speed and stability for each application.
Response time: 23 µs (S-HSPD) / 50 µs (HSPD) / 250 µs (FINE) / 500 µs (TURBO) / 1 ms (SUPER) / 4 ms (ULTRA) / 16 ms (MEGA) / 64 ms (TERA)
Control output: open-collector, 30 V max, 100 mA max per output
Residual voltage: 1.4 V at 10 mA; 2 V at 10–100 mA
External input: none on this expansion unit
Control outputs: 1
Unit expansion: up to 16 units (17 total including main unit)
The supply voltage ranges from 10 to 30 VDC, with 10% ripple P-P or less. A Class 2 or LPS power source is required. Power consumption stays at 870 mW or less (34 mA at 24 V). With ECO ON, it drops to 800 mW; with ECO FULL, 710 mW. Furthermore, the open-collector output handles 100 mA per channel, which covers most PLC and relay interfaces.
The unit weighs approximately 48 g. Operating temperature ranges from -20 to +55 °C with no freezing. In addition, the amplifier derates when users expand multiple units. The compact body fits standard DIN rail mounting inside control panels. However, detailed dimensions are not published in the available data.
First, mount the expansion unit beside a main amplifier on the DIN rail. Next, connect the expansion cable to the main unit. The FS-N42N draws power and communication through this connection. Then, wire the NPN output to the PLC input or load. After that, set the response mode and threshold through the OLED display. Finally, run a test with the target workpiece and confirm stable detection.
Keep the fiber cable bend radius within the manufacturer limit. Also, avoid routing the cable near high-voltage lines. For long cable runs, verify the output voltage drop stays within the load tolerance.
1 × Keyence FS-N42N amplifier unit
1 × Expansion connection cable
1 × Mounting bracket
1 × Instruction sheet
Q1: What is the difference between the FS-N42N and a main unit?
A: The FS-N42N is an expansion unit. It needs a main amplifier to supply power and control. It cannot work alone.
Q2: How many units can one main amplifier support?
A: Users can connect up to 16 expansion units, giving 17 total including the main unit. A dual-output unit counts as two.
Q3: Which response mode should I choose?
A: Use 23 µs for high-speed detection. Choose longer modes such as 4 ms or 16 ms when the target moves slowly or when the environment has dust and vibration.
Q4: Does the FS-N42N include external input?
A: No. This expansion model has no external input. Only the control output is available.
Q5: How fast can you ship this item?
A: We ship by Fedex, UPS, or DHL. Most orders leave the warehouse within 1–3 business days after payment confirmation.
| Brand Name | |
| Model No. | FS-N42N |
| Product Type | Digital Fiber Optic Sensor Amplifier |
| hasMerchantReturnPolicy | Adjust according to reality |
| Shippingdetails | Adjust according to reality |
