The **M2RT-04-R/BL** is a specific model of a **Miniature Rotary DIP Switch**. These components are widely used on Printed Circuit Boards (PCBs) to allow manual configuration of electronic circuits (such as setting device IDs, baud rates, or modes). --- ### 1. Component Overview The part number typically breaks down into several technical specifications: | Feature | Specification | Description | |:---|:---|:---| | **Type** | Rotary DIP Switch | A manual switch that rotates to select different output codes. | | **Positions** | 4 Positions | Offers four distinct selectable states (usually 0, 1, 2, 3). | | **Mounting Type** | Through-Hole (THT) | Designed to be soldered into holes on a PCB. | | **Actuator** | Raised / Flush | Depending on the "R" suffix, it usually features a raised shaft or flat slot for a screwdriver. | | **Color/Code** | Blue (BL) | Often indicates the housing color or specific coding logic. | --- ### 2. Electrical Specifications These switches are designed for low-power signal switching rather than high-current power applications. * **Switching Capacity:** Usually 25mA to 100mA at 24V DC. * **Contact Resistance:** Typically < 100mΩ. * **Insulation Resistance:** > 100MΩ at 250V DC. * **Dielectric Strength:** 250V AC for 1 minute. * **Operating Temperature:** Generally ranges from -25°C to +70°C. --- ### 3. Pin Configuration and Truth Table For a 4-position rotary switch, there are typically 3 or 4 pins (Common, Pin 1, and Pin 2). The switch uses **Binary** or **Direct** output logic. #### Example Truth Table (Binary Coded): | Position | Common to Pin 1 | Common to Pin 2 | Result (Decimal) | |:---:|:---:|:---:|:---:| | 0 | OFF | OFF | 0 | | 1 | ON | OFF | 1 | | 2 | OFF | ON | 2 | | 3 | ON | ON | 3 | --- ### 4. Common Applications * **Industrial Controls:** Setting addresses for sensors or PLC modules. * **Telecommunications:** Configuring modems or routers. * **Consumer Electronics:** Selecting modes on garage door openers or remote controls. * **Development Boards:** Hard-coding hardware logic or boot sequences. --- ### 5. Mechanical Dimensions The "M2" prefix often refers to a miniature footprint, typically around **7mm x 7mm** or **10mm x 10mm**, making them ideal for space-constrained circuit designs.