Objectives  In order to realize the rapid data exchange of the monitoring module in a grid-connected control system, the fault tolerance rate of communication data is improved and the extra CPU occupancy is saved by using Direct Memory Access (DMA) and interrupt communication technology to solve the problem of variable length transmission.

  Methods  This paper is based on the communication protocol between the configuration software of the monitoring module and the microcontroller in a grid-connected control system. It designs a communication handshake flow between configuration and main controller, taking STM32F417 as the main controller, with the help of a serial interface hardware circuit. The use of DMA and interrupt communication technology is proposed to overcome the shortcomings of the traditional serial communication data fixed-length transceiver.

  Results  On the grid-connected control device of a ship's integrated power system, DMA and interrupt communication technology is adopted to realize the variable-length transmission function of the monitoring data, thereby improving the serial communication data transmission capacity and data tolerance.

  Conclusions  The results of this study have certain practical guiding significance and reference value for the development of monitoring modules for ship grid control systems.