...to fan system control...
EXCEL 5000™  fan controllers monitor all room and zone controllers -- every one -- ensuring that requirements for air temperature, pressure, and circulation are met at least cost.  Air flows and temperatures can be continually adjusted to minimize terminal unit energy use without comfort loss in any zone.  Fans run only as fast as needed, not at near-constant, design-day speeds.  Controllers rated for smoke control are available. 

With Honeywell controller-mounted and mobile interfaces, there are no codes, no cryptic messages to interpret.  System monitoring, commands and adjustments are easy.