The PLC (Programmable Logic Controller) has the anti jamming to be tough, the dependability is high, the programming easy characteristic, is extensively applied in the domain of industrial control. At current, foreign and domestic had a lot of scholars to perform the quite systematic research and the function to soft PLC, already succeeded improvement based on fixed PC open style soft. The almost ten remaining years of life come, alongside with the Soc piece on organized research improvement, the embedded chip got the small control of programmable controller's center to cause the industrial field enormous attention and the academic circle, conducted the preliminary application and the research.
But the current a variety of companies use the particular main line standard in the main engine's of small PLC with each type of development module between link, causes its development every kind of input output module expansion to set up on the respective business design guide rail, or and the module of small PLC CPU have to be the short distance; If a small PLC control's controlled plant's check point and the control point are quite scattered in the equipment, the partial check points and the control point are away from the electricity cabinet to be far, will cause the controlled plant is long the check point and the control point to the small PLC connecting lead; Alternatively, implementation cycle of PLC user program in milliseconds, it is hard to more multifarious control algorithms embedded in a PLC program to reach the goal of complex control system. FPGA is the algorithm control cooperates the processor, the main line of CAN is the unit PLC master-control and between each type of expansion module the main line data communication standard PLC circuit structure, the expansion new general small programmable controller.
The system comprises the module of central control, a variety of extensive function module, modules of host computer and module of CAN-bus communication. As the data communication bus of the CAN bus can meet the demand of user that the extensive functional could be installed close to the device controlled, which results in the wire linking the drive and sensing device with the system could be reduced extremely especially when the sensing pointers and object control drives were dispersed and parts of them were left from the electrical control cabinet. Alternatively, one or more human machine interfaces could be mounted in.