The **FRS-3E-R** typically refers to a high-precision, sub-miniature **Photoelectric Sensor** (specifically a retro-reflective fiber optic sensor head) manufactured by companies like **Keyence**. These parts are designed for high-end industrial automation where space is limited and high reliability is required. --- ### 1. Technical Specifications The following table outlines the key electronic and physical characteristics of the FRS-3E-R: | Feature | Specification | | :--- | :--- | | **Sensor Type** | Retro-reflective Fiber Optic | | **Fiber Diameter** | 1.0 mm to 1.3 mm (Core) | | **Bending Radius** | R2 to R4 (Highly Flexible) | | **Sensing Distance** | Up to 150mm - 300mm (depends on amplifier) | | **Material** | Stainless Steel / Plastic Optical Fiber | | **Operating Temp** | -40°C to +70°C | --- ### 2. Core Electronic Components & Operation The FRS-3E-R functions as a "head" unit that must be connected to an external **Amplifier Unit** (such as the FS-N series). Its electronic operation is divided into two main paths: #### A. The Emitter (Light Source) * **LED Transmission:** The electronic amplifier sends a modulated light pulse (usually Red LED or Infrared) through the plastic fiber. * **Modulation:** The signal is pulsed at specific frequencies to prevent interference from ambient factory lighting. #### B. The Receiver (Detection) * **Retro-reflective Principle:** The light travels out of the fiber, hits a reflector, and returns to the same head. * **Phototransistor Logic:** The returning light is converted back into an electrical signal. If an object breaks the beam, the light intensity drops, triggering the amplifier's output (PNP/NPN). --- ### 3. Key Electronic Features 1. **Chemical Resistance:** The "R" in the suffix often denotes high flexibility or specific environmental resistance, allowing the fiber to be routed through tight robotic joints without signal attenuation. 2. **Fiber Core Design:** Uses multi-core or high-index plastic to ensure that the light signal remains coherent over the length of the cable. 3. **Signal Stability:** Because it is a passive electronic component (it carries light, not electricity), it is immune to **Electromagnetic Interference (EMI)**, making it ideal for use near high-voltage motors or welders. --- ### 4. Typical Wiring Integration The FRS-3E-R itself does not have wires, but its fiber leads plug into an amplifier. The amplifier's electronic interface usually follows this standard: ```yaml Brown: +24V DC (Power) Blue: 0V (Grounded) Black: Control Output (NPN/PNP) White: External Input (Remote Calibration) ```