A--->Indicator of A channel level power
B---> Indicator of program
C--->Indicator of B channel level power
D---> Used batteries : two red LED blink. Your device stops, even if a program is running. Change the batteries.
E---> Weak batteries indicator : two orange LED blink. Your device is still on operation.
F---> Disconnection warning light : blinks when the electrodes are disconnected.