# Protection Features The Control ([REV-31-1595](https://www.revrobotics.com/rev-31-1595/)) and Expansion Hub ([REV-31-1153](https://www.revrobotics.com/rev-31-1153/)) were designed with a number of protection features built into the device. These include the following: * Reverse battery input protection * Electrostatic discharge (ESD) protection on all connections * Over-current protection on all power buses * Digital I/O bus * I2C bus * Analog bus * USB * Servo bus per pair (0-1, 2-3, 4-5) * Encoder bus * Over-current monitoring for individual Motor Channels * Keyed and locking connectors * Fail-safe mode at communication loss --- # Agent Instructions: Querying This Documentation If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question. Perform an HTTP GET request on the current page URL with the `ask` query parameter: ``` GET https://docs.revrobotics.com/duo-control/control-system-overview/protection-features.md?ask= ``` The question should be specific, self-contained, and written in natural language. The response will contain a direct answer to the question and relevant excerpts and sources from the documentation. Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.