The Serial Encoder Card CX-Basic is designed to be used in conjunction with serial controlled display units. The encoder has serial communication ports, SER1, SER2 and USB port and is installed in the lift machine room, next to the lift controller. It accepts signals like floor position code, directional arrows as well as lift status signals like MAINTENANCE, OVERLOAD, OUT OF ORDER etc. through 24 optoisolated inputs. The signals are then transmitted through SER1, which is a 4-wire serial communication link, to all the display units connected to it.