Description
The input and output unit is the I/O interface part of the PLC, mainly composed of units such as hall call, floor selection inside the car, floor and direction indication, door opening and closing, upper and lower leveling in the shaft, forced speed change switch, door lock, safety protection relay, maintenance, fire protection, ladder parking, weighing, etc. The input unit is:
(1) The call unit outside the hall is used to register, memorize, and eliminate the call signals outside the hall at each floor, and also has the function of “opening the hall outside the hall without a driver”. The call signals for the full selection mode are 2N-2 (N is the number of floors), and the call signals for the lower selection mode are N;
(2) The floor selection unit in the car is responsible for registering, eliminating, and indicating pre-selected floor commands. The number of call signals is the number of elevator stop floors
(3) Open and close the door button, input PLC to control the opening and closing of the car door (the hall door also acts simultaneously);
(4) The upper and lower leveling device is used to ensure accurate leveling of the elevator car during parking on each floor. It is usually set on the car roof. When the elevator car approaches the pre-selected landing station, the upper leveling sensor is limited to enter the magnetic shield, and the elevator continues to run slowly. When the lower leveling sensor enters the magnetic shield again, the upward contactor coil loses power, and the brake stops with a brake;
(5) The upper and lower limit forced speed change switches are used to protect the safety of high-speed operation of the elevator and avoid accidents such as hitting the top or squatting at the bottom. When the elevator reaches the upper and lower stations, the upper and lower limit forced speed change switches installed next to the elevator car strike the board, and the signal is input to the PLC. The PLC sends a speed change signal to force the elevator to slow down and run to the level position;
(6) The door lock device (or car door and hall door interlocking protection device), the closure of the car door and the locking of each hall door are prerequisites for the normal start and operation of the elevator;
(7) Safety circuit, usually including car emergency stop switch, car roof emergency stop switch, safety gear switch, speed limiter rope break switch, speed limiter overspeed switch, pit emergency stop switch, phase sequence protection relay, upper and lower limit switches, etc;
(8) Maintenance, fire protection, and parking are the three operating modes of elevators. Maintenance operation is the slow running mode during elevator maintenance, and there are two operating modes for fire protection: returning to the base station and dedicated to firefighters. Parking status eliminates internal and external call signals, automatically returns to the parking floor, closes the door, and powers off;
(9) The weighing unit is used to detect the load of the elevator car, determine whether the elevator is under load, fully loaded, or overloaded, and then output a digital signal to the PLC to compensate for the starting torque based on the load situation, ensuring smooth operation of the elevator.
The output unit is:
(1) Floor and direction indicator unit, including elevator up and down direction indicator lights, floor indicator lights, and station alarm clocks. Currently, the direction and floor indicator lights mainly have a seven segment code display mode and a dot matrix display mode. This system adopts a seven segment code display mode;
(2) The door opening and closing unit is used to control the opening and closing of the elevator’s hall and car doors. After the automatic orientation is completed or the elevator stops smoothly, the PLC provides relevant instructions, and the frequency conversion door machine completes the door opening and closing action.
NASI02
NASM01
NBIM01
NBIM02
NCIS01
NCIS02
NCOM01
NCOM03
NCOM04
NCTM01
NDS001
NDSI01
NDSI02
NDSM01
NDSM02
NDSM03
NDSM05
NDSO01
NDSO04
NGCM02
NLIM02