Honeywell 900RR0-0300 CPU Redundancy Rack | Modular Chassis for Secure & Scalable Automation Architecture The 900RR0-0300 CPU Redundancy Rack is a precision-engineered modular chassis designed to serve as the foundation for secure, scalable, and highly available industrial automation architectures. In critical process environments where system downtime is not an option, this redundancy rack provides the infrastructure necessary to implement fault-tolerant control systems with