The optional hot-swappable, redundant (backup) dual power supply system virtually removes the risk of sync loss due to power supply unit failure, minimizing disruption in operations. Unique to the ECO8000 and ECO8020, the unit periodically tests the backup power supply to verify its performance. If the test fails, a fault will be indicated on the LED fault indicator as well as an error message for backup power supply replacement - providing extra assurance that the backup power supply will be ready when needed.