The escalator main control board ES.01/B features 20 low-voltage inputs, 2 high-voltage inputs, 14 relay outputs, 3 transistor outputs, 2 CAN interfaces (one for connecting the fault acquisition board and fault display board of this escalator, and the other for remote monitoring from the control room), 1 RS232 interface (for connecting a handheld operator), and 1 expansion interface (for interface expansion; up to 3 expansion boards can be added).