这个程序是利用VC编写的一个从机串口响应modbus查询命令程序，实现RTU方式，3.5和1.5个字符时间检测，CRC和LRC校验。-This program is written using VC as a response from the machine serial modbus query command procedure, to achieve RTU mode, 3.5 and 1.5 characters time detection, CRC and LRC check.

hart通信，实现信息预览，量程修改，零点迁移等功能。普通命令-hart communications, information preview, range changes, zero migration and other functions. Common commands