The **W2TS-2BY-R2/K** belongs to a specific series of industrial automation components, typically categorized as a **Terminal Relay Board** or an **Interface Relay Module**. These devices are used to bridge the gap between low-power control systems (like a PLC) and high-power field devices. Below is the technical breakdown of its electronic parts and specifications. ### 1. Component Overview The device is a multi-channel relay module designed for DIN rail mounting. It integrates electromagnetic relays, protection circuitry, and LED indicators onto a single PCB. | Feature | Specification (Typical for R2/K variants) | | :--- | :--- | | **Relay Type** | Electromagnetic (Replaceable or Soldered) | | **Number of Points** | 2 Points (2-channel) | | **Input Voltage** | 24V DC (Standard for PLC logic) | | **Contact Form** | 1a (SPST-NO) or 1c (SPDT) per relay | | **Mounting Type** | DIN Rail (35mm) | | **Wiring Method** | Screw Terminal or Push-in (depending on "K" sub-variant) | --- ### 2. Key Electronic Parts and Functions #### A. The Relay (The Core Component) The "R2" designation often refers to the relay type used. * **Function:** Actuates a physical switch using an electromagnet. * **Contact Material:** Usually Silver Alloy (AgSnO2) for high conductivity and resistance to welding. * **Switching Capacity:** Typically handles 5A to 10A at 250V AC / 30V DC. #### B. Protection Circuitry To ensure the longevity of the control system, the board includes: 1. **Flyback Diode (Freewheeling Diode):** Placed across the relay coil to suppress voltage spikes (back-EMF) when the coil is de-energized. This protects the PLC transistor outputs. 2. **Varistor (Optional):** Some models include a MOV (Metal Oxide Varistor) to protect the contacts from arcing when switching inductive loads. #### C. LED Indicators * **Visual Diagnostics:** A small SMD LED is placed in series with each input channel. It lights up when the coil is energized, allowing technicians to verify if the control signal is active without using a multimeter. #### D. Terminal Blocks * **Input Side:** Where the 24V DC control signal from the PLC is connected. * **Output Side:** The "Dry Contacts" where the load (Motor starter, solenoid, lamp) is connected. --- ### 3. Wiring Diagram Concept The internal layout follows this logic for each channel: ```text [Input Terminal +] ----> [LED] ----> [Relay Coil] ----> [Input Terminal -] | (Isolation) | [Output Common] --------[ Contact Arm / Switch ]-------- [Output NO] ``` ### 4. Application Context * **Signal Isolation:** Protects sensitive electronics from high-voltage noise. * **Current Amplification:** Allows a 20mA PLC output to control a 5A industrial load. * **Maintenance:** The "R2" series often allows for individual relays to be replaced if the contacts wear out, without replacing the entire terminal block. ---