The ALARM LED will be ON when you have more than 30 V different between the capacitor banks.
The LOAD LED will be ON when the capacitors are charging.
The READY LED will be ON when the capacitors are charged.
The optical fibers (Rx/Tx) are used for the dialog with the E-Load.
The LED display shows the voltage on a capacitors bank.
The Control Cell which regulates the flash is directly plug on the flasher cabinet.