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本文目录
- 1. 概述
- 2. 安装
- 3. Beispiel
概述
libmodbus是一个快速且可移植的Modbus库，支持传统的RS-232、RS-422、RS-485和EthernetAusrüstung。
安装
Linux、MacOS、FreeBSD、WIN32等可直接通过包管理器安装 libmodbus
libmodbus官网Download：https://libmodbus.org/releases/libmodbus-3.1.7.tar.gz
githubDownload：https://github.com/stephane/libmodbus.git
//进入解压目录
cd libmodbus-3.1.7
//配置编译选项（以ARM为例，--build为Das System构架 --host为编译对应Das SystemWerkzeuge链，--prefix为输出目录，选项均是可选的）
./configure --build=i686 --host=arm-linux --enable-static --prefix=[install path]/
//编译安装
make && make installBeispiel
RTU master
#include <stdio.h>
#include <stdlib.h>
#include <memory.h>
#include "modbus.h"
int main(void)
{
int i = 0;
int regs = 0;
modbus_t *ctx = NULL;
uint16_t tab_reg[64] = {0};
//Öffnen.端口: 端口，Porter Rate，Prüfstand.，Datenplatz，Stoppen Sie Platz
ctx = modbus_new_rtu("/dev/ttyUSB0", 9600, 'N', 8, 1);
//设置从机Adresse
modbus_set_slave(ctx, 1);
//设置Die Serie模式(可选)
modbus_rtu_set_serial_mode(ctx, MODBUS_RTU_RS485);
//设置RTS(可选)
modbus_rtu_set_rts(ctx, MODBUS_RTU_RTS_UP);
//建立Verbindung
if (modbus_connect(ctx) == -1) {
fprintf(stderr, "Connexion failed: %s\n", modbus_strerror(errno));
modbus_free(ctx);
return -1;
}
//设置应答延时(可选)
modbus_set_response_timeout(ctx, 0, 1000000);
while (1)
{
memset(tab_reg, 0, sizeof(tab_reg));
//读Register.设置：Register-Adresse、Anzahl、Daten缓冲
regs = modbus_read_registers(ctx, 0, 20, tab_reg);
if (rc == -1) {
fprintf(stderr, "%s\n", modbus_strerror(errno));
continue;
}
printf("[%4d][read num = %d]", num++, regs);
for (i = 0; i < 20; ++i)
{
printf("<%#x>", tab_reg[i]);
}
printf("\n");
sleep(1);
}
}- RTU-Master流程总结：
- 初始化 modbus 指针
- 设置Von der StationID
- 建立Verbindung
- Lesen und halten Register/输入Register./离散输入/线圈输入
- Schreiben eines einzelnen Registers/多ein Register./多位Daten
- SchließenVerbindung
RTU slave
#include <stdio.h>
#include <unistd.h>
#include <stdlib.h>
#include <error.h>
#include <memory.h>
#include "modbus.h"
int main(void)
{
int i = 0;
int rc = 0;
modbus_t *ctx = NULL;
modbus_mapping_t *mb_mapping = NULL;
uint8_t query[MODBUS_TCP_MAX_ADU_LENGTH];
//Öffnen.端口: 端口，Porter Rate，Prüfstand.，Datenplatz，Stoppen Sie Platz
ctx = modbus_new_rtu("/dev/ttyUSB0", 9600, 'N', 8, 1);
//设置从机Adresse
modbus_set_slave(ctx, 1);
//设置Die Serie模式
//modbus_rtu_set_serial_mode(ctx, MODBUS_RTU_RS485);
//设置RTS
//modbus_rtu_set_rts(ctx, MODBUS_RTU_RTS_UP);
//建立Verbindung
if (modbus_connect(ctx) == -1) {
fprintf(stderr, "Connexion failed: %s\n", modbus_strerror(errno));
modbus_free(ctx);
return -1;
}
mb_mapping = modbus_mapping_new(MODBUS_MAX_READ_BITS, 0,
MODBUS_MAX_READ_REGISTERS, 0);
if (mb_mapping == NULL) {
fprintf(stderr, "Failed to allocate the mapping: %s\n",
modbus_strerror(errno));
modbus_free(ctx);
return -1;
}
//初始化几ein Register.
mb_mapping->tab_registers[0] = 1;
mb_mapping->tab_registers[1] = 2;
mb_mapping->tab_registers[2] = 3;
mb_mapping->tab_registers[3] = 4;
mb_mapping->tab_registers[4] = 5;
mb_mapping->tab_registers[5] = 6;
while (1)
{
memset(query, 0, sizeof(query));
rc = modbus_receive(ctx, query);
if (rc > 0) {
modbus_reply(ctx, query, rc, mb_mapping);
} else if (rc == -1) {
//Connection closed by the client or error
break;
}
}
printf("Quit the loop: %s\n", modbus_strerror(errno));
modbus_mapping_free(mb_mapping);
if (s != -1) {
close(s);
}
modbus_close(ctx);
modbus_free(ctx);
}RTU-Slave流程总结:
- 初始化 modbus 指针;
- 设置Von der StationID;
- modbus_mapping_new初始化Register.，返回一个modbus_mapping_t 指针;
- 建立Verbindung;
- 调用 modbus_receive 函数判断Die Serie的EmpfangDaten，负责Empfang处理及回复。
TCP master
#include <stdio.h>
#include <unistd.h>
#include <stdlib.h>
#include <error.h>
#include <memory.h>
#include <sys/socket.h>
#include "modbus.h"
void main(void)
{
int i;
int regs = 0;
int num = 0;
modbus_t *ctx = NULL;
uint16_t tab_reg[64] = {0};
ctx = modbus_new_tcp("127.0.0.1",8000);
modbus_set_slave(ctx, 1);
modbus_connect(ctx);
modbus_set_response_timeout(ctx, 0, 1000000);
while (1)
{
memset(tab_reg, 0, sizeof(tab_reg));
regs = modbus_read_registers(ctx, 0, 20, tab_reg);
printf("[%4d][read num = %d]", num++, regs);
for (i = 0; i < 20; i++)
{
printf("<%#x>", tab_reg[i]);
}
printf("\n");
sleep(1);
}
modbus_close(ctx);
modbus_free(ctx);
}TCP slave
#include <stdio.h>
#include <unistd.h>
#include <stdlib.h>
#include <error.h>
#include <memory.h>
#include <sys/socket.h>
#include "modbus.h"
int main(void)
{
int i = 0;
int rc = 0;
modbus_t *ctx = NULL;
modbus_mapping_t *mb_mapping = NULL;
uint8_t query[MODBUS_TCP_MAX_ADU_LENGTH];
//Öffnen.端口: ip, port
ctx = modbus_new_tcp("127.0.0.1", 8000);
//设置从机Adresse
modbus_set_slave(ctx, 1);
//建立Verbindung
if (modbus_connect(ctx) == -1) {
fprintf(stderr, "Connexion failed: %s\n", modbus_strerror(errno));
modbus_free(ctx);
return -1;
}
mb_mapping = modbus_mapping_new(MODBUS_MAX_READ_BITS, 0,
MODBUS_MAX_READ_REGISTERS, 0);
if (mb_mapping == NULL) {
fprintf(stderr, "Failed to allocate the mapping: %s\n",
modbus_strerror(errno));
modbus_free(ctx);
return -1;
}
//初始化几ein Register.
mb_mapping->tab_registers[0] = 1;
mb_mapping->tab_registers[1] = 2;
mb_mapping->tab_registers[2] = 3;
mb_mapping->tab_registers[3] = 4;
mb_mapping->tab_registers[4] = 5;
mb_mapping->tab_registers[5] = 6;
while (1)
{
memset(query, 0, sizeof(query));
rc = modbus_receive(ctx, query);
if (rc > 0) {
modbus_reply(ctx, query, rc, mb_mapping);
} else if (rc == -1) {
//Connection closed by the client or error
break;
}
}
printf("Quit the loop: %s\n", modbus_strerror(errno));
modbus_mapping_free(mb_mapping);
if (s != -1) {
close(s);
}
modbus_close(ctx);
modbus_free(ctx);
}
Die一次接觸,善用資源學習
不知道怎么用的，来学习一下。
试试看，能否正常使用。
值得学习
值得学习参考.
值得学习参考