Keyence FS-N40 Fiber Amplifier Expansion Unit

Keyence FS-N40 Fiber Amplifier Expansion Unit

The FS-N40 from Keyence belongs to the FS-N40 series of digital fiber optic sensor amplifiers. Specifically, this model serves as a zero line type expansion unit. It contains no built-in control outputs of its own. Instead, it extends the capability of a main amplifier unit when your application requires multiple sensing points. Furthermore, when connected to a multi-output unit such as the FS-MC8N/P or an NU series communication unit, the FS-N40 counts as one output channel.

Technical Specifications

The FS-N40 supports a wide range of response time settings to match different detection needs. At its fastest setting (S-HSPD), response time reaches 23 µs. Users can also select 50 µs (HSPD), 250 µs (FINE), 500 µs (TURBO), 1 ms (SUPER), 4 ms (ULTRA), 16 ms (MEGA), or 64 ms (TERA) depending on the required stability and speed balance. The light source is a red four-element LED with a 660 nm wavelength, ensuring consistent emission for reliable fiber optic sensing.

For external input, the unit accepts signals with an ON time of 2 ms or longer and an OFF time of 20 ms or longer. The FS-N40 draws power from a 10 to 30 VDC supply. Its power consumption is 870 mW or less during normal operation. Additionally, ECO mode reduces consumption to 800 mW, while ECO FULL lowers it to 710 mW.

Mechanical and Environmental Parameters

The amplifier housing uses polycarbonate for the main body and cover. This material provides good dimensional stability and electrical insulation. Measuring approximately 23 g in weight, the unit is lightweight and minimizes mechanical stress on DIN rail installations. The operating temperature range spans -20 to +55 °C with no freezing allowed. However, this range derates as you add more expansion units. For systems with 3 to 10 connected units, the upper limit drops to +50 °C. For 11 to 16 units, it falls to +45 °C. Therefore, plan your panel thermal design accordingly when building large arrays.

Vibration resistance is rated at 10 to 55 Hz with a double amplitude of 1.5 mm across X, Y, and Z axes for two hours each. Shock resistance reaches 500 m/s², tested three times per axis.

Installation Guide

First, mount the FS-N40 onto a 35 mm DIN rail or use the optional mounting bracket. Next, connect the expansion connector to the main amplifier or the preceding expansion unit. The system supports up to 16 expansion units, giving 17 total units including the main amplifier. Besides, keep the communication wiring short and shielded to avoid noise interference. Finally, verify the supply voltage stays within 10 to 30 VDC before powering on the system.

Packaging List

• Keyence FS-N40 Expansion Unit × 1

• Mounting Clip × 1

• Instruction Manual × 1

FAQ

Q1: What is the difference between the FS-N40 and a main amplifier unit?
A: The FS-N40 is a zero line type expansion unit with no control outputs. It only works together with a main amplifier unit to add sensing channels.

Q2: How many FS-N40 units can connect to one main amplifier?
A: You can connect up to 16 expansion units, which gives 17 total units including the main amplifier.

Q3: What response time settings does the FS-N40 offer?
A: It offers eight settings from 23 µs (S-HSPD) up to 64 ms (TERA), so you can balance speed and stability for each application.

Q4: Does the FS-N40 require a separate power supply?
A: No. It receives power through the expansion connector from the main amplifier unit, which uses a 10 to 30 VDC supply.

Q5: How does expansion affect the operating temperature?
A: The base range is -20 to +55 °C. With 3 to 10 units, the upper limit becomes +50 °C. With 11 to 16 units, it drops to +45 °C.