Distributed Control System Example
- Moderately inexpensive, mid-range design
  - 1-10 MIPS, 1-16 MB RAM -- times several CPUs per system



  - Mid-range 16- and 32-bit CISC distributed processors
  - A few real-time I/O control loops for each CPU
  - Low-speed networking among CPUs and among systems
  - Mission-critical system
    - Non-redundant hardware; ordinary software development
    - Electromechanical safeties provide failure protection
  - Moderate development costs ($1M - $10M)
  - Hundreds to thousands of systems sold
  - 25-50 year lifetime
- Real-life systems:
  - High-rise elevators
  - Large-building air handling
  - Public transit systems