The **99-R99I** is an identification code primarily associated with **Rethink Robotics** for their **Sawyer** and **Baxter** series of collaborative robots (cobots). Specifically, it refers to the **Interconnect Board** or the **Controller PC interface**. --- ### Core Specifications & Component Breakdown The 99-R99I serves as a critical bridge between the robot's main processing unit and its articulated joints/sensors. | Component Category | Description | Key Functions | | :--- | :--- | :--- | | **Logic Processing** | High-speed FPGA or Microcontroller | Handles real-time synchronization between joint encoders and the CPU. | | **Connectivity** | EtherCAT / High-speed Serial | Manages the internal communication bus to the actuators. | | **Power Management** | Integrated Voltage Regulators | Steps down the 24V/48V main supply to 3.3V or 5V for logic circuits. | | **Diagnostic LEDs** | Status Indicators | Provides visual feedback on board health, power status, and data transmission. | --- ### Key Technical Features 1. **High-Speed Communication:** It utilizes a specialized protocol (often based on EtherCAT) to ensure sub-millisecond latency. This is vital for the robot's "Force Sensing" capabilities, allowing it to stop instantly upon contact with a human. 2. **Safety Circuitry:** The board integrates with the **E-Stop (Emergency Stop)** loop. If the 99-R99I detects a hardware failure or a heartbeat timeout, it triggers a physical relay to cut motor power. 3. **EMI Shielding:** Given its proximity to high-power brushless DC motors, the board features extensive decoupling capacitors and ground planes to prevent electromagnetic interference from corrupting data signals. --- ### Common Maintenance & Troubleshooting If you are repairing a unit with this part number, look for these common electronic failure points: * **Capacitor Aging:** Over time, the electrolytic capacitors near the power input may bulge, leading to intermittent "Communication Lost" errors. * **Firmware Mismatch:** Replacing a 99-R99I often requires a re-flash of the Robot Operating System (ROS) environment to ensure the hardware version matches the software kernel. * **Connector Corrosion:** The high-density pins are sensitive to moisture and oxidation, which can cause erratic joint behavior. ---