Systems can initiate shut-downs, sound alarms, and report conditions by calling out to pagers, radios, or phones. Time-stamped data is recorded for historical analysis. Systems have their own power supply. They can report ac power loss and continue to measure and store data. Monitoring and control can be based on time or measured parameters, or a series of events.
Systems measure nearly every type of sensor.
Systems support hardwire or wireless communication to a central computer.