In the process of processing palm fruit into crude palm oil there are five general processes. The first process is the sterilization process, which is the process of boiling the palm fruit, the second process is the process of separating the fruit from the bunch, the third process is the process of separating the fruit from the seeds, the fourth process is pressing the process of separating the oil from the fruit, the fifth process is the process of clarification, namely the process of separating oil, water and dirt. On this basis, the right action is needed for each stage of the process so that the final results can be maximized. Another factor that determines the quality of results and efficiency of the plant is equipment that must be in standard conditions, both the quality and quantity of each tool. The capacity of a process with the others must be synchronous and the operation of each process is also a factor that determines the performance of a palm oil mill. The processes that occur in palm oil processing can be controlled by the PLC as the controller. PLC programming can use the change signal method in the form of a ladder diagram design. With the ladder diagram, the process carried out will run sequentially. Because in the process there are parts which are backward processes and onward processes, this method is right used here. By using the change signal method, the results of the ladder diagram construction are 96 units, 916 relay contacts, and the resulting program capacity is 18 KB.