The **CASM-S-D2-R3** is a specific sensor component designed by **Festo**. It is a displacement encoder (sensor) used primarily for position sensing in pneumatic or electric actuators. It utilizes a **potentiometric** measuring principle. --- ### 1. Technical Specifications The following table highlights the core electronic and physical attributes of the CASM-S-D2-R3: | Feature | Specification | | :--- | :--- | | **Measuring Principle** | Potentiometric (Analog) | | **Ambient Temperature** | -40°C to +120°C | | **Protection Class** | IP65 (Dust-tight and water-jet resistant) | | **Linearity Error** | ± 0.05% | | **Nominal Resistance** | 5 kOhm (± 20%) | | **Connection Type** | M12, 8-pin plug | --- ### 2. Electronic Components & Design The "Electronic Parts" of this device consist of a precision resistive element and a wiper system integrated into a robust housing. * **Resistive Track:** High-quality conductive plastic or ceramic substrate that provides a continuous change in resistance as the actuator moves. * **Wiper Mechanism:** A multi-finger precious metal contact that glides along the track to pick up the voltage signal. * **Signal Processing:** The device outputs a ratiometric voltage. This means the output signal is directly proportional to the supply voltage and the position of the rod. * **Shielding:** The internal electronics are shielded against electromagnetic interference (EMC) to ensure signal stability in industrial environments. --- ### 3. Pin Allocation (M12 Connector) Understanding the wiring is critical for integrating the CASM-S-D2-R3 into a control system (like a PLC). | Pin | Function | Description | | :--- | :--- | :--- | | 1 | **n.c.** | Not connected | | 2 | **n.c.** | Not connected | | 3 | **Signal** | Output voltage (position signal) | | 4 | **GND** | Ground for the supply voltage | | 5 | **Supply** | Input voltage (typically 10V or 24V DC) | --- ### 4. Application Context The "S-D2" designation typically refers to its compatibility with Festo's **DGCI** or **DDPC** series pneumatic cylinders. It is used in closed-loop positioning systems where the controller needs constant feedback on the exact location of the piston rod to adjust air pressure or braking.