[C++知识库]【modbus.h使用】C++ Modbus Tcp实例-读写float

// libmodbus_use.cpp : 此文件包含 "main" 函数。程序执行将在此处开始并结束。
//

#include <iostream>
#include "modbus.h"

#define CODE_BOOL_READ		(0x01)			 /*BOOL 读功能码 */
#define CODE_BOOL_WRITE		(0x05)/*(0x0F)*/ /*BOOL 写功能码 */
#define CODE_INT_READ		(0x03)			 /*INT  读功能码 */
#define CODE_INT_WRITE		(0x10)			 /*INT  写功能码 */
#define CODE_REAL_READ		CODE_INT_READ	 /*REAL 读功能码 */
#define CODE_REAL_WRITE		CODE_INT_WRITE   /*REAL 写功能码 */
//读取（ 寄存器1-高16位AB-value1        寄存器2-低16位CD-value2 ）模式的float     
float modbus_float_inverse(uint16_t value1, uint16_t value2)
{
	float temp;
	char* Modbus_HoldReg[4];
	Modbus_HoldReg[0] = ((char*)(&temp)) + 3;
	Modbus_HoldReg[1] = ((char*)(&temp)) + 2;
	Modbus_HoldReg[2] = ((char*)(&temp)) + 1;
	Modbus_HoldReg[3] = ((char*)(&temp)) + 0;
	*Modbus_HoldReg[0] = (value1 >> 8) & 0xff;
	*Modbus_HoldReg[1] = value1 & 0xff;
	*Modbus_HoldReg[2] = (value2 >> 8) & 0xff;
	*Modbus_HoldReg[3] = value2 & 0xff;

	return temp;
}
//  读取（ 寄存器1-低16位CD-value1     寄存器2-高16位AB-value2 ）模式的float
float modbus_float(uint16_t value1, uint16_t value2)
{
	float temp;
	char* Modbus_HoldReg[4];
	Modbus_HoldReg[0] = ((char*)(&temp)) + 3;
	Modbus_HoldReg[1] = ((char*)(&temp)) + 2;
	Modbus_HoldReg[2] = ((char*)(&temp)) + 1;
	Modbus_HoldReg[3] = ((char*)(&temp)) + 0;
	*Modbus_HoldReg[0] = (value2 >> 8) & 0xff;
	*Modbus_HoldReg[1] = value2 & 0xff;
	*Modbus_HoldReg[2] = (value1 >> 8) & 0xff;
	*Modbus_HoldReg[3] = value1 & 0xff;

	return temp;
}

float modbus_float_inverse(uint8_t value1, uint8_t value2, uint8_t value3, uint8_t value4)
{
	float temp;
	char* Modbus_HoldReg[4];
	Modbus_HoldReg[0] = ((char*)(&temp)) + 3;
	Modbus_HoldReg[1] = ((char*)(&temp)) + 2;
	Modbus_HoldReg[2] = ((char*)(&temp)) + 1;
	Modbus_HoldReg[3] = ((char*)(&temp)) + 0;
	*Modbus_HoldReg[0] = value1;
	*Modbus_HoldReg[1] = value2;
	*Modbus_HoldReg[2] = value3;
	*Modbus_HoldReg[3] = value4;

	return temp;
}

int main()
{
	// 创建modbus对象create a modbus object
	modbus mb = modbus("127.0.0.1", 502);

	//设置从站 set slave id
	mb.modbus_set_slave_id(1);

	// 连接服务器connect with the server
	mb.modbus_connect();
	///
		// 读取线圈 read coil                        function 0x01
	bool read_coil;
	mb.modbus_read_coils(0, 1, &read_coil);//1开始

	//读取离散输入 read input bits(discrete input)  function 0x02
	bool read_bits;
	mb.modbus_read_input_bits(0, 1, &read_bits);//10001开始

	// 读取保持寄存器read holding registers           function 0x03
	uint16_t read_holding_regs[1];
	mb.modbus_read_holding_registers(0, 1, read_holding_regs);//40001开始

	// 读取模拟输入寄存器read input registers             function 0x04
	uint16_t read_input_regs[1];
	mb.modbus_read_input_registers(0, 1, read_input_regs);//30001开始
///
	//写入单线圈 write single coil                function 0x05
	mb.modbus_write_coil(0, true);//1开始

	//写入单寄存器 write single reg                 function 0x06
	mb.modbus_write_register(0, 123);//40001开始

	// 写入多线圈write multiple coils             function 0x0F
	bool write_cols[4] = { true, true, true, true };
	mb.modbus_write_coils(0, 4, write_cols);

	// 写入多寄存器write multiple regs              function 0x10
	uint16_t write_regs[4] = { 123, 123, 123 };
	mb.modbus_write_registers(0, 4, write_regs);
	/
	//写入浮点数
	float data = 3512.5549;

	uint16_t write_regs2[2] = { 0 };

	memcpy(write_regs2, &data, sizeof(float));

	for (int i = 0; i < 2; i++) // ABCD模式   write_regs2[0]-高16位AB-寄存器1   write_regs2[1]-低16位CD-寄存器2
		printf("data change write_regs[%d] = 0x%02x\n", i, write_regs2[i]);

	uint16_t t;
	t = write_regs2[0];
	write_regs2[0] = write_regs2[1];
	write_regs2[1] = t;

	for (int i = 0; i < 2; i++) // CDAB模式 写入。
		printf("data change write_regs[%d] = 0x%02x\n", i, write_regs2[i]);
	mb.modbus_write_registers(4, 2, write_regs2);

	//读取浮点数
	uint16_t read_regs[2];
	mb.modbus_read_holding_registers(4, 2, read_regs);

	float f1 = modbus_float(read_regs[1], read_regs[0]);
	printf("float number is %7f\n", f1);

	// 关闭连接并释放内存
	mb.modbus_close();
	// std::cout << getfloat(0x80, 0x00, 0xc3, 0xb5);
	std::cout << "The End!\n";
}

void getfloat()
{
	float fresult;
	unsigned short int iresult;
	char rec[4] = { 0x80,0x00,0xc3,0xb5 };
	char* modebus[4];

	modebus[0] = ((char*)(&fresult)) + 1;
	modebus[1] = ((char*)(&fresult)) + 0;
	modebus[2] = ((char*)(&fresult)) + 3;
	modebus[3] = ((char*)(&fresult)) + 2;

	*modebus[0] = rec[0];
	*modebus[1] = rec[1];
	*modebus[2] = rec[2];
	*modebus[3] = rec[3];
	printf("输出浮点数： %f\r\n", fresult);

	modebus[0] = ((char*)(&iresult)) + 1;
	modebus[1] = ((char*)(&iresult)) + 0;
	*modebus[0] = rec[0];
	*modebus[1] = rec[1];
	printf("输出整数： %d\r\n", iresult);
}

float getfloat(unsigned char A, unsigned char B, unsigned char C, unsigned char D)
{
	float fresult;
	unsigned short int iresult;
	//char rec[4] = { 0x80,0x00,0xc3,0xb5 };
	char rec[4] = { A,B,C,D };
	char* modebus[4];

	modebus[0] = ((char*)(&fresult)) + 1;
	modebus[1] = ((char*)(&fresult)) + 0;
	modebus[2] = ((char*)(&fresult)) + 3;
	modebus[3] = ((char*)(&fresult)) + 2;

	*modebus[0] = rec[0];
	*modebus[1] = rec[1];
	*modebus[2] = rec[2];
	*modebus[3] = rec[3];
	return fresult;

	/*printf("输出浮点数： %f\r\n", fresult);
	modebus[0] = ((char*)(&iresult)) + 1;
	modebus[1] = ((char*)(&iresult)) + 0;
	*modebus[0] = rec[0];
	*modebus[1] = rec[1];
	printf("输出整数： %d\r\n", iresult);*/
}
// 运行程序: Ctrl + F5 或调试 >“开始执行(不调试)”菜单
// 调试程序: F5 或调试 >“开始调试”菜单

// 入门使用技巧: 
//   1. 使用解决方案资源管理器窗口添加/管理文件
//   2. 使用团队资源管理器窗口连接到源代码管理
//   3. 使用输出窗口查看生成输出和其他消息
//   4. 使用错误列表窗口查看错误
//   5. 转到“项目”>“添加新项”以创建新的代码文件，或转到“项目”>“添加现有项”以将现有代码文件添加到项目
//   6. 将来，若要再次打开此项目，请转到“文件”>“打开”>“项目”并选择 .sln 文件

参考：

C++ modbus 通信中Long与Float数据解析_小鱼仙官的博客-CSDN博客_float inversehttps://blog.csdn.net/yuchunhai321/article/details/119725011

fanzhe98/modbuspp: A C++ Library for Modbus TCP Client Protocol (github.com)https://github.com/fanzhe98/modbuspp

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