基于Libmodbus的走航式海表温度传感器总线协议设计

针对船用海水表层水温观测以人工观测为主的现状，基于跨平台的Modbus库Libmodbus的走航式海洋表层水温监测系统，通过在船舶一侧布放处于船舶吃水线范围的水温传感器来采集表层水温信息。采用RS485/Modbus协议实现多站多点联网，构成分布式系统，进行海水表层温度的自动采集。上位机基于Modbus-RTU协议，并添加循环冗余校验以保证其对水温传感器的远程控制和表层水温信息采集功能的可靠性、安全性。该系统不仅运行稳定，操作简单方便，还具有可移植性和可扩展性。实验结果表明，该系统可以稳定可靠地监测海洋表层水温，实现表层水温的随船在线测量。

Libmodbus-based bus protocol design for navigational sea surface temperature sensors

In this study, a design is proposed based on the cross-platform Modbus library Libmodbus’ navigational sea surface temperature monitoring system to address the current situation in which the sea surface water temperature observations are mainly conducted via manual processes. In this design, the sensors located under the waterline toward the side of the ship are used to obtain the surface water temperature. The RS485/Modbus protocol is adopted to implement a multistation multipoint network to obtain a distributed system for automatically obtaining the sea surface temperature. The host computer is based on the Modbus-RTU protocol and involves cyclic redundancy check to ensure remote control of the water temperature sensor and the reliability as well as safety of the surface water temperature collection function. The designed system is not only stable, simple, and easy to operate but also portable and scalable. The experimental results show that the designed system can monitor the sea surface temperature in a stable and reliable manner and realize online measurement of the surface water temperature with respect to a ship.