ABB PM802F/ABB PM803F on the AC800F controller mainboard has 6 slots and 1 power slot, among which 2 slots adopt fast DMA technology for direct high-speed data communication with the CPU. These 2 slots realize the information transmission of the control layer based on standard TCP/IP Ethernet by inserting Ethernet modules. The remaining 4 slots F1… F4 uses interrupt mode to exchange data with CPU and main memory, each module can generate its own interrupt source, powerful interrupt controller and advanced multi-task operating system can quickly respond to the interrupt information from the 4 communication modules and quickly exchange data with them. At the same time, the error report information of communication modules can be received in real time through the control of priority. The bandwidth of the data bus of the CPU board is 100MB/s, which ensures that the large amount of information data from various communication modules can be quickly transferred to the CPU unit for processing. In order to ensure the maximum accuracy of data, the main memory chip of the AC800F CPU unit has error detection and modification capabilities, which can check the 2-bit error of 32-bit data word and modify the 1-bit error. PM803 motherboard improves the storage capacity of the main memory to 16MB, and implements the large-capacity control program on the AC800F controller. But the corresponding program keeps the device up to date.