PLC receives the stop command (X06), and the stop command triggers the internal bit M41 → timer T14 (17 seconds). Timer T14 is used to control the machine to stop after the material is loaded on the belt conveyor. Timer T14 triggers internal bit M114 → reset output bit Y4 (K7), 4 × main control contactor (km4) of belt conveyor is powered off and reset, 4 × belt conveyor is shut down. Part of the program ladder is shown in Figure 4-4. 4 × unit return (X04) has no input, and its input logic reversely triggers internal timer T13 (7S) → triggers internal bit M113 → resets output bit Y3 (K6), resets output bit control relay K6, and the main contactor of 3 × unit (shale shaker) is powered off and reset. In the same shutdown process, all belt conveyors of the conveyor system are finally stopped.