Modbus动态链接库供多语言使用 | Go
Modbus协议控制动态链接库
应用场景
基于各门语言都有各自的modbus协议库，且良莠不齐，而且在具体的框架下可能存在版本依赖问题，
而且对modbus协议存在比较多的细节处理，可以查看modbus slave、或者modbus poll中相关的配置可知，
数据类型对应读写寄存器个数、大小端的处理等等细节，所以将以常用的场景下的配置编写动态链接库供其他语言调用。
编程语言
因为我不会写C语言，这里使用Go语言编写代码，以C函数分享库的模式编译成动态链接库
将以Python与Node.js调用的示例演示
辅助工具下载地址
Modbus Poll: 激活码(仅供学习 5A5742575C5D10) -> 模拟主站
链接: https://pan.baidu.com/s/1Sk2m6HWTU0-hE82-BxPvKA 提取码: 1fwn
Modbus Slave: 激活码(仅供学习 5455415451475662) -> 模拟从站
链接: https://pan.baidu.com/s/137w1-2gGQ3bETvbyBefNQg 提取码: 9433
编写Go代码示例 使用Cgo引入C函数
- Modbus TCP示例
package main
/*
#include <stdlib.h>
*/
import (
"C"
"bytes"
"encoding/binary"
"fmt"
"log"
"math"
"time"
"github.com/goburrow/modbus"
)
import "strings"
var handler *modbus.TCPClientHandler
//export Connect
func Connect(ip *C.char, port C.int) C.int {
log.Printf("Connect ...")
handler = modbus.NewTCPClientHandler(fmt.Sprintf("%s:%d", C.GoString(ip), int(port)))
handler.Timeout = 250 * time.Millisecond
err := handler.Connect()
if err != nil {
log.Printf("Connect error: %v", err)
return -1
}
return 0
}
//export Close
func Close() C.int {
log.Printf("Close ...")
err := handler.Close()
if err != nil {
log.Printf("Close error: %v", err)
return -1
}
return 0
}
//ReadRegister 一般错误返回 -1 连接失败返回 -3
//export ReadRegister
func ReadRegister(slaveId C.int, address C.int, dataType *C.char, data *C.double) C.int {
var results []byte
var err error
handler.SlaveId = byte(slaveId)
client := modbus.NewClient(handler)
dt := C.GoString(dataType)
switch dt {
case "int16":
results, err = client.ReadInputRegisters(uint16(address), 1)
case "int32", "float":
results, err = client.ReadInputRegisters(uint16(address), 2)
case "int64", "double":
results, err = client.ReadInputRegisters(uint16(address), 4)
}
if err != nil {
switch {
case strings.Contains(err.Error(), "connection"):
log.Println("Connection error:", err)
return -3
case strings.Contains(err.Error(), "timeout"):
log.Println("Timeout error:", err)
return -1
default:
log.Println("Other error:", err)
return -1
}
}
var value float64
switch dt {
case "int16":
var intValue int16
err = binary.Read(bytes.NewReader(results), binary.BigEndian, &intValue)
value = float64(intValue)
case "int32":
var intValue int32
err = binary.Read(bytes.NewReader(results), binary.BigEndian, &intValue)
value = float64(intValue)
case "float":
var floatValue float32
err = binary.Read(bytes.NewReader(results), binary.BigEndian, &floatValue)
value = float64(floatValue)
case "int64":
var intValue int64
err = binary.Read(bytes.NewReader(results), binary.BigEndian, &intValue)
value = float64(intValue)
case "double":
err = binary.Read(bytes.NewReader(results), binary.BigEndian, &value)
}
if err != nil {
log.Println(err)
return -1
}
*data = C.double(value)
return 0
}
//ReadHoldingRegister 一般错误返回 -1 连接失败返回 -3
//export ReadHoldingRegister
func ReadHoldingRegister(slaveId C.int, address C.int, dataType *C.char, data *C.double) C.int {
var results []byte
var err error
handler.SlaveId = byte(slaveId)
client := modbus.NewClient(handler)
dt := C.GoString(dataType)
// startTime := time.Now()
switch dt {
case "int16":
results, err = client.ReadHoldingRegisters(uint16(address), 1)
case "int32", "float":
results, err = client.ReadHoldingRegisters(uint16(address), 2)
case "int64", "double":
results, err = client.ReadHoldingRegisters(uint16(address), 4)
}
// endTime := time.Now()
// // 计算时间差
// duration := endTime.Sub(startTime)
// fmt.Printf("Takes: %v\n", duration)
if err != nil {
switch {
case strings.Contains(err.Error(), "connection"):
log.Println("Connection error:", err)
return -3
case strings.Contains(err.Error(), "timeout"):
log.Println("Timeout error:", err)
return -1
default:
log.Println("Other error:", err)
return -1
}
}
var value float64
switch dt {
case "int16":
var intValue int16
err = binary.Read(bytes.NewReader(results), binary.BigEndian, &intValue)
value = float64(intValue)
case "int32":
var intValue int32
err = binary.Read(bytes.NewReader(results), binary.BigEndian, &intValue)
value = float64(intValue)
case "float":
var floatValue float32
err = binary.Read(bytes.NewReader(results), binary.BigEndian, &floatValue)
value = float64(floatValue)
case "int64":
var intValue int64
err = binary.Read(bytes.NewReader(results), binary.BigEndian, &intValue)
value = float64(intValue)
case "double":
err = binary.Read(bytes.NewReader(results), binary.BigEndian, &value)
}
if err != nil {
log.Println(err)
return -1
}
*data = C.double(value)
return 0
}
//export WriteRegister
func WriteRegister(slaveId C.int, address C.int, dataType *C.char, value C.double) C.int {
var err error
handler.SlaveId = byte(slaveId)
client := modbus.NewClient(handler)
dt := C.GoString(dataType)
switch dt {
case "int16":
var intValue int16 = int16(value)
_, err = client.WriteSingleRegister(uint16(address), uint16(intValue))
case "int32":
var intValue int32 = int32(value)
results := make([]byte, 4)
binary.BigEndian.PutUint32(results, uint32(intValue))
_, err = client.WriteMultipleRegisters(uint16(address), uint16(len(results)/2), results)
case "float":
var floatValue float32 = float32(value)
results := make([]byte, 4)
binary.BigEndian.PutUint32(results, math.Float32bits(floatValue))
_, err = client.WriteMultipleRegisters(uint16(address), uint16(len(results)/2), results)
case "int64":
var intValue int64 = int64(value)
results := make([]byte, 8)
binary.BigEndian.PutUint64(results, uint64(intValue))
_, err = client.WriteMultipleRegisters(uint16(address), uint16(len(results)/2), results)
case "double":
var doubleValue float64 = float64(value)
results := make([]byte, 8)
binary.BigEndian.PutUint64(results, math.Float64bits(doubleValue))
_, err = client.WriteMultipleRegisters(uint16(address), uint16(len(results)/2), results)
default:
return -1
}
if err != nil {
switch {
case strings.Contains(err.Error(), "connection"):
log.Println("Connection error:", err)
return -3
case strings.Contains(err.Error(), "timeout"):
log.Println("Timeout error:", err)
return -1
default:
log.Println("Other error:", err)
return -1
}
}
return 0
}
func main() {}
- Modbus RTU示例
package main
/*
#include <stdlib.h>
*/
import (
"C"
"bytes"
"encoding/binary"
"log"
"math"
"time"
"github.com/goburrow/modbus"
)
import "strings"
var handler *modbus.RTUClientHandler
//export Connect
func Connect(port *C.char, baudrate C.int) C.int {
log.Printf("Connect ...")
handler = modbus.NewRTUClientHandler(C.GoString(port))
handler.BaudRate = int(baudrate)
handler.DataBits = 8
handler.Parity = "N"
handler.StopBits = 1
handler.Timeout = 250 * time.Millisecond
err := handler.Connect()
if err != nil {
log.Printf("Connect error: %v", err)
return -1
}
return 0
}
//export Close
func Close() C.int {
log.Printf("Close ...")
err := handler.Close()
if err != nil {
log.Printf("Close error: %v", err)
return -1
}
return 0
}
//ReadRegister 一般错误返回 -1 连接失败返回 -3
//export ReadRegister
func ReadRegister(slaveId C.int, address C.int, dataType *C.char, data *C.double) C.int {
var results []byte
var err error
handler.SlaveId = byte(slaveId)
client := modbus.NewClient(handler)
dt := C.GoString(dataType)
switch dt {
case "int16":
results, err = client.ReadInputRegisters(uint16(address), 1)
case "int32", "float":
results, err = client.ReadInputRegisters(uint16(address), 2)
case "int64", "double":
results, err = client.ReadInputRegisters(uint16(address), 4)
}
if err != nil {
switch {
case strings.Contains(err.Error(), "connection"):
log.Println("Connection error:", err)
return -3
case strings.Contains(err.Error(), "timeout"):
log.Println("Timeout error:", err)
return -1
default:
log.Println("Other error:", err)
return -1
}
}
var value float64
switch dt {
case "int16":
var intValue int16
err = binary.Read(bytes.NewReader(results), binary.BigEndian, &intValue)
value = float64(intValue)
case "int32":
var intValue int32
err = binary.Read(bytes.NewReader(results), binary.BigEndian, &intValue)
value = float64(intValue)
case "float":
var floatValue float32
err = binary.Read(bytes.NewReader(results), binary.BigEndian, &floatValue)
value = float64(floatValue)
case "int64":
var intValue int64
err = binary.Read(bytes.NewReader(results), binary.BigEndian, &intValue)
value = float64(intValue)
case "double":
err = binary.Read(bytes.NewReader(results), binary.BigEndian, &value)
}
if err != nil {
log.Println(err)
return -1
}
*data = C.double(value)
return 0
}
//ReadHoldingRegister 一般错误返回 -1 连接失败返回 -3
//export ReadHoldingRegister
func ReadHoldingRegister(slaveId C.int, address C.int, dataType *C.char, data *C.double) C.int {
var results []byte
var err error
handler.SlaveId = byte(slaveId)
client := modbus.NewClient(handler)
dt := C.GoString(dataType)
// startTime := time.Now()
switch dt {
case "int16":
results, err = client.ReadHoldingRegisters(uint16(address), 1)
case "int32", "float":
results, err = client.ReadHoldingRegisters(uint16(address), 2)
case "int64", "double":
results, err = client.ReadHoldingRegisters(uint16(address), 4)
}
// endTime := time.Now()
// // 计算时间差
// duration := endTime.Sub(startTime)
// fmt.Printf("Takes: %v\n", duration)
if err != nil {
switch {
case strings.Contains(err.Error(), "connection"):
log.Println("Connection error:", err)
return -3
case strings.Contains(err.Error(), "timeout"):
log.Println("Timeout error:", err)
return -1
default:
log.Println("Other error:", err)
return -1
}
}
var value float64
switch dt {
case "int16":
var intValue int16
err = binary.Read(bytes.NewReader(results), binary.BigEndian, &intValue)
value = float64(intValue)
case "int32":
var intValue int32
err = binary.Read(bytes.NewReader(results), binary.BigEndian, &intValue)
value = float64(intValue)
case "float":
var floatValue float32
err = binary.Read(bytes.NewReader(results), binary.BigEndian, &floatValue)
value = float64(floatValue)
case "int64":
var intValue int64
err = binary.Read(bytes.NewReader(results), binary.BigEndian, &intValue)
value = float64(intValue)
case "double":
err = binary.Read(bytes.NewReader(results), binary.BigEndian, &value)
}
if err != nil {
log.Println(err)
return -1
}
*data = C.double(value)
return 0
}
//export WriteRegister
func WriteRegister(slaveId C.int, address C.int, dataType *C.char, value C.double) C.int {
var err error
handler.SlaveId = byte(slaveId)
client := modbus.NewClient(handler)
dt := C.GoString(dataType)
switch dt {
case "int16":
var intValue int16 = int16(value)
_, err = client.WriteSingleRegister(uint16(address), uint16(intValue))
case "int32":
var intValue int32 = int32(value)
results := make([]byte, 4)
binary.BigEndian.PutUint32(results, uint32(intValue))
_, err = client.WriteMultipleRegisters(uint16(address), uint16(len(results)/2), results)
case "float":
var floatValue float32 = float32(value)
results := make([]byte, 4)
binary.BigEndian.PutUint32(results, math.Float32bits(floatValue))
_, err = client.WriteMultipleRegisters(uint16(address), uint16(len(results)/2), results)
case "int64":
var intValue int64 = int64(value)
results := make([]byte, 8)
binary.BigEndian.PutUint64(results, uint64(intValue))
_, err = client.WriteMultipleRegisters(uint16(address), uint16(len(results)/2), results)
case "double":
var doubleValue float64 = float64(value)
results := make([]byte, 8)
binary.BigEndian.PutUint64(results, math.Float64bits(doubleValue))
_, err = client.WriteMultipleRegisters(uint16(address), uint16(len(results)/2), results)
default:
return -1
}
if err != nil {
switch {
case strings.Contains(err.Error(), "connection"):
log.Println("Connection error:", err)
return -3
case strings.Contains(err.Error(), "timeout"):
log.Println("Timeout error:", err)
return -1
default:
log.Println("Other error:", err)
return -1
}
}
return 0
}
func main() {}
编译动态链接库
Go语言支持交叉编译成各个平台的二进制运行程序，但是Cgo不支持，可以去寻找第三方库去处理这个问题，这里选择用Docker容器
- 编译命令
windows下是modbus.dll，Linux下是 modbus.so，Macos下是 modbus.dylib
go build -o modbus.so -buildmode=c-shared main.go
- 其他平台编译，比如树莓派，选择使用docker容器
这里找一个 arm32v7 的docker容器，可以通过 docker search arm32v7的方式去搜索，我是试了几个选了个node版本的容器，
不同版本里面的 GLIBC 可能不一样，需要先查看你的树莓派上 GLIBC版本，通过命令 strings /lib/*/libc.so.* | grep GLIBC，
根据版本我选择了node v16的版本下载镜像
- 下载镜像、创建容器
docker run -itd --name raspberry arm32v7/node:16
- 进入容器、安装go环境
wget -e http_proxy=127.0.0.1:10809 https://studygolang.com/dl/golang/go1.17.linux-armv6l.tar.gz
tar -zxvf go1.17.linux-armv6l.tar.gz go/
mv go /usr/local/go
# 安装vim
apt-get update
apt-get install vim -y
# 加入系统环境
vim /etc/profile # 加入内容到最后一行 export PATH=$PATH:/usr/local/go/bin
source /etc/profile # 每次进入容器都要执行一次，要是没有找到go命令的话
- 将Go代码文件拷贝至容器
docker cp modbus_dir raspberry:/ # 将modbus_dir拷贝至容器raspberry的 / 目录下
- 进入容器编译动态链接库
docker exec -it raspberry /bin/bash
cd modbus_dir
go build -o modbus.so -buildmode=c-shared main.go
- 将编译后的动态链接库拷贝到宿主机
exit # 退出容器
docker cp raspberry:/modbus_dir/modbus.so ./ # 拷贝至当前目录
应用示例
- Python
modbus tcp示例
import ctypes
import platform
# 加载共享库
print(platform.system())
if platform.system() == "Windows":
modbus = ctypes.CDLL('./modbus.dll')
elif platform.system() == "Darwin":
modbus = ctypes.CDLL('./modbus.dylib')
else: # 树莓派
modbus = ctypes.CDLL('./modbus.so')
# 定义函数参数类型和返回类型
modbus.ReadRegister.argtypes = [ctypes.c_int, ctypes.c_int, ctypes.c_char_p, ctypes.POINTER(ctypes.c_double)]
modbus.ReadRegister.restype = ctypes.c_int
modbus.WriteRegister.argtypes = [ctypes.c_int, ctypes.c_int, ctypes.c_char_p, ctypes.c_double]
modbus.WriteRegister.restype = ctypes.c_int
modbus.ReadHoldingRegister.argtypes = [ctypes.c_int, ctypes.c_int, ctypes.c_char_p, ctypes.POINTER(ctypes.c_double)]
modbus.ReadHoldingRegister.restype = ctypes.c_int
modbus.Connect.argtypes = [ctypes.c_char_p, ctypes.c_int]
modbus.Connect.restype = ctypes.c_int
modbus.Close.argtypes = []
modbus.Close.restype = ctypes.c_int
# 调用ReadRegister函数
modbus.Connect(b'192.168.1.138', 502)
# 写控制寄存器
for i in range(50):
data = ctypes.c_double()
result = modbus.WriteRegister(1, 30, b'float', 123.45 + i)
if result == -3:
print('Connect error.')
if result == 0:
print('Write success.')
# 读控制寄存器 | 读输入寄存器时改成 ReadRegister
for i in range(50):
data = ctypes.c_double()
result = modbus.ReadHoldingRegister(1, 30, b'int16', ctypes.byref(data))
print('Read Result:', result, data.value)
modbus.Close()
modbus rtu示例
import ctypes
import platform
# 加载共享库
print(platform.system())
if platform.system() == "Windows":
modbus = ctypes.CDLL('./modbus-rtu.dll')
elif platform.system() == "Darwin":
modbus = ctypes.CDLL('./modbus-rtu.dylib')
else: # 树莓派
modbus = ctypes.CDLL('./modbus-rtu.so')
# 定义函数参数类型和返回类型
modbus.ReadRegister.argtypes = [ctypes.c_int, ctypes.c_int, ctypes.c_char_p, ctypes.POINTER(ctypes.c_double)]
modbus.ReadRegister.restype = ctypes.c_int
modbus.WriteRegister.argtypes = [ctypes.c_int, ctypes.c_int, ctypes.c_char_p, ctypes.c_double]
modbus.WriteRegister.restype = ctypes.c_int
modbus.ReadHoldingRegister.argtypes = [ctypes.c_int, ctypes.c_int, ctypes.c_char_p, ctypes.POINTER(ctypes.c_double)]
modbus.ReadHoldingRegister.restype = ctypes.c_int
modbus.Connect.argtypes = [ctypes.c_char_p, ctypes.c_int]
modbus.Connect.restype = ctypes.c_int
modbus.Close.argtypes = []
modbus.Close.restype = ctypes.c_int
# 调用ReadRegister函数
modbus.Connect(b'COM2', 9600)
# 写控制寄存器
for i in range(50):
data = ctypes.c_double()
result = modbus.WriteRegister(1, 30, b'float', 123.45 + i)
if result == -3:
print('Connect error.')
if result == 0:
print('Write success.')
# 读控制寄存器 | 读输入寄存器时改成 ReadRegister
for i in range(50):
data = ctypes.c_double()
result = modbus.ReadHoldingRegister(1, 30, b'int16', ctypes.byref(data))
print('Read Result:', result, data.value)
modbus.Close()
- Node.js
这是我在electron进行软件开发过程中封装的函数
调用顺序: DefineModbus -> connectModbus -> writeRegisterAsync/readRegisterAsync/readHoldingRegisterAsync -> connectModbus
const ffi = require('ffi-napi');
const ref = require('ref-napi');
const double = ref.types.double;
const doublePtr = ref.refType(double);
const path = require('path');
import {checkPort} from './net';
let dllPath: string;
console.log(`当前平台: ${process.platform}`) // darwin
let dllName = 'modbus.dll';
if (process.platform === 'darwin') {
dllName = 'modbus.dylib';
}
if (process.env.MODE === 'development') {
dllPath = path.resolve(`extraResources/dlls/${dllName}`);
} else {
dllPath = path.join(process.resourcesPath, 'extraResources', 'dlls', dllName);
}
let modbus: any;
const closeModbus = () => {
return new Promise((resolve, reject) => {
modbus.Close.async(
(err: any, result: any) => {
if (err) {
reject(err);
} else {
resolve(result);
}
},
);
});
};
const connectModbus = (ip: string, port: number) => {
return new Promise((resolve, reject) => {
modbus.Connect.async(
ip,
port,
(err: any, result: any) => {
if (err) {
reject(err);
} else {
resolve(result);
}
},
);
});
};
const writeRegisterAsync = (
slaveId: number,
startAddress: number,
dataType: string,
val: number,
) => {
return new Promise((resolve, reject) => {
modbus.WriteRegister.async(
slaveId,
startAddress,
dataType,
val,
(err: any, result: any) => {
if (err) {
reject(err);
} else {
resolve(result);
}
},
);
});
};
const readRegisterAsync = (
slaveId: number,
startAddress: number,
dataType: string,
data: any,
) => {
return new Promise((resolve, reject) => {
modbus.ReadRegister.async(
slaveId,
startAddress,
dataType,
data,
(err: any, result: any) => {
if (err) {
reject(err);
} else {
resolve(result);
}
},
);
});
};
const readHoldingRegisterAsync = (
slaveId: number,
startAddress: number,
dataType: string,
data: any,
) => {
return new Promise((resolve, reject) => {
modbus.ReadHoldingRegister.async(
slaveId,
startAddress,
dataType,
data,
(err: any, result: any) => {
if (err) {
reject(err);
} else {
resolve(result);
}
},
);
});
};
/**
* modbus-serial库的使用
*/
export const ConnectModbus = async (ip: string, port: number) => {
try {
const result = await connectModbus(ip, port);
return [result, 0];
} catch (e) {
return [-1, 0];
}
}
export const CloseModbus = async () => {
try {
const result = await closeModbus();
return [result, 0];
} catch(e) {
return [-1, 0];
}
}
export const ReadByModbusTcp = async (
slaveId: number,
startAddress: number,
dataType: string,
method: string = 'Input',
) => {
const data = ref.alloc(double);
try {
let result: any;
if (method === 'Input') {
result = await readRegisterAsync(slaveId, startAddress, dataType, data);
} else {
result = await readHoldingRegisterAsync(slaveId, startAddress, dataType, data);
}
return [result, data.deref() as number];
} catch (e) {
console.log(`e :${e}`);
return [0, 0];
}
}
export const WriteByModbusTcp = async (
slaveId: number,
startAddress: number,
dataType: string,
val: number,
) => {
try {
const result: any = await writeRegisterAsync(
slaveId,
startAddress,
dataType,
val,
);
return [result, val];
} catch (e) {
return [0, 0];
}
}
export const DefineModbus = async () => {
try {
modbus = ffi.Library(dllPath, {
ReadRegister: ['int', ['int', 'int', 'string', doublePtr]],
ReadHoldingRegister: ['int', ['int', 'int', 'string', doublePtr]],
WriteRegister: ['int', ['int', 'int', 'string', 'double']],
Connect: ['int', ['string', 'int']],
Close: ['int', []],
});
console.log('Define Modbus Success.');
} catch (e) {
console.log(`defineModbus error: ${e}`);
}
return dllPath;
}
export const CheckConnected = async (ip: string, port: number) => {
try {
const result = await checkPort(ip, port);
return true;
} catch (e) {
return false;
}
}
最后
这里只写了 读写控制寄存器、读输入寄存器，支持数据类型 int16/int32/int64/float/double
可以根据需要加入自己的代码，比如线圈的读写控制设备启停等
动态链接库、源码地址
链接: https://pan.baidu.com/s/1q40gHnftqzGJtUgfws_sdw 提取码: 72o2
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