A Study of FPGA Instance Based PLC Architecture Design and Automatic Generation Algorithm of Logic Code

In this paper, an architecture of FPGA instance based PLC and a method of converting IL (instruction list) of PLC to instances are proposed assuming that the PLC is installed on the cloud. It is attempted to improve responsiveness by dedicated circuitry using instances (libraries) and concurrent processing that are specific features of FPGA hardware. The proposed architecture in the FPGA consists of the instance part (calculation circuit that is correspond to the instruction of the PLC) the input/output circuit/output memory, and the state machine. In this paper, a benchmark test of PLC is converted into instances by automatic conversion algorithm to be implemented with the proposed architecture, and it is confirmed by logic simulation that the FPGA instance based PLC operates at high speed as expected.