【EdgeX（16）】 ：边缘计算，工业4.0，golang开发，使用Apache PLC4X项目对PLC设备进行modbus协议对接，实现读取和发送代码学习中

前言

---

相关EdgeX Foundry 全部分类：
https://blog.csdn.net/freewebsys/category_9437788.html

本文的原文连接是:
https://blog.csdn.net/freewebsys/article/details/127585739

未经博主允许不得转载。
博主CSDN地址是：https://blog.csdn.net/freewebsys
博主掘金地址是：https://juejin.cn/user/585379920479288
博主知乎地址是：https://www.zhihu.com/people/freewebsystem

1，关于Apache PLC4X

---

目前手上没有PLC设备，只是进行学习。

PLC行业发展趋势

PLC软件的算法需要针对工业4.0的生产要求做出进一步优化，在结合人工智能和大数据的基础上，PLC行业应该进一步优化软件，提供更符合行业实际应用的工具，提升工业算法解决问题的能力并降低算法复杂程度。另外，PLC作为一种辅助工业制造的工具，底层程序应该进一步封装为简洁易用的工具包，对上提供简单接口供技术人员调用，实现复杂生产工艺的操作简洁化。在用户交互方面，PLC工具需要结合具体场景对技术人员的操作习惯进一步理解，并依据实际情况制定切合实际的用户交互界面，进一步增强系统的交互性能。

项目地址：
https://plc4x.apache.org/
https://github.com/apache/plc4x/

有golang 的代码：
https://plc4x.apache.org/users/getting-started/plc4go.html
https://github.com/apache/plc4x/tree/develop/plc4go

视频学习资料：

ApacheConAsia2021 IOT0808：Christofe - 使用Apache PLC4X的高安全性IIoT通信-英文

多角度讲解MODBUS通信在控制项目上的应用

多角度讲解MODBUS通信在控制项目上的应用

About Apache PLC4X
Apache PLC4X is an effort to create a set of libraries for communicating with industrial grade programmable logic controllers (PLCs) in a uniform way. We are planning on shipping libraries for usage in:

Java
Go
C (not ready for usage)
Python (not ready for usage)
C# (.Net) (not ready for usage)

支持多个语音，但是做IOT还是研究golang 版本的吧。方便部署开发。

可以支持的协议：
https://plc4x.apache.org/users/protocols/index.html

2，使用golang代码进行读写操作plc设备

---

读取plc设备的demo例子，官方的example里面的：

package main

import (
	"fmt"

	"github.com/apache/plc4x/plc4go/pkg/api"
	"github.com/apache/plc4x/plc4go/pkg/api/drivers"
	"github.com/apache/plc4x/plc4go/pkg/api/model"
)

func main() {
	driverManager := plc4go.NewPlcDriverManager()
	drivers.RegisterModbusTcpDriver(driverManager)

	// Get a connection to a remote PLC
	crc := driverManager.GetConnection("modbus-tcp://192.168.23.30")

	// Wait for the driver to connect (or not)
	connectionResult := <-crc
	if connectionResult.GetErr() != nil {
		fmt.Printf("error connecting to PLC: %s", connectionResult.GetErr().Error())
		return
	}
	connection := connectionResult.GetConnection()

	// Make sure the connection is closed at the end
	defer connection.BlockingClose()

	// Prepare a read-request
	readRequest, err := connection.ReadRequestBuilder().
		AddTagAddress("tag", "holding-register:26:REAL").
		Build()
	if err != nil {
		fmt.Printf("error preparing read-request: %s", connectionResult.GetErr().Error())
		return
	}

	// Execute a read-request
	rrc := readRequest.Execute()

	// Wait for the response to finish
	rrr := <-rrc
	if rrr.GetErr() != nil {
		fmt.Printf("error executing read-request: %s", rrr.GetErr().Error())
		return
	}

	// Do something with the response
	if rrr.GetResponse().GetResponseCode("tag") != model.PlcResponseCode_OK {
		fmt.Printf("error an non-ok return code: %s", rrr.GetResponse().GetResponseCode("tag").GetName())
		return
	}

	value := rrr.GetResponse().GetValue("tag")
	fmt.Printf("Got result %f", value.GetFloat32())
}

写入信息代码：

package main

import (
	"fmt"

	"github.com/apache/plc4x/plc4go/pkg/api"
	"github.com/apache/plc4x/plc4go/pkg/api/drivers"
	"github.com/apache/plc4x/plc4go/pkg/api/model"
)

func main() {
	driverManager := plc4go.NewPlcDriverManager()
	drivers.RegisterModbusTcpDriver(driverManager)

	// Get a connection to a remote PLC
	crc := driverManager.GetConnection("modbus-tcp://192.168.23.30")

	// Wait for the driver to connect (or not)
	connectionResult := <-crc
	if connectionResult.GetErr() != nil {
		fmt.Printf("error connecting to PLC: %s", connectionResult.GetErr().Error())
		return
	}
	connection := connectionResult.GetConnection()

	// Make sure the connection is closed at the end
	defer connection.BlockingClose()

	// Prepare a write-request
	writeRequest, err := connection.WriteRequestBuilder().
		AddTagAddress("tag", "holding-register:26:REAL", 2.7182818284).
		Build()
	if err != nil {
		fmt.Printf("error preparing read-request: %s", connectionResult.GetErr().Error())
		return
	}

	// Execute a read-request
	wrc := writeRequest.Execute()

	// Wait for the response to finish
	wrr := <-wrc
	if wrr.GetErr() != nil {
		fmt.Printf("error executing write-request: %s", wrr.GetErr().Error())
		return
	}

	if wrr.GetResponse().GetResponseCode("tag") != model.PlcResponseCode_OK {
		fmt.Printf("error an non-ok return code: %s", wrr.GetResponse().GetResponseCode("tag").GetName())
		return
	}
	fmt.Print("Result: SUCCESS\n")
} 

支持的设备plc 设备协议：

ads bacnetip cbus eip knxnetip modbus s7 等驱动的实现，不太清楚具体含义。
可能是协议啥的吧。

代码中的使用的是 modbus2 的驱动去调用的。

感觉上应该和modbus 获取的数据类似。

依赖的其他golang的开源项目：

github.com/IBM/netaddr
github.com/ajankovic/xdiff
github.com/fatih/color
github.com/gdamore/tcell/v2
github.com/gopacket/gopacket
github.com/icza/bitio
github.com/jacobsa/go-serial
github.com/k0kubun/go-ansi
github.com/libp2p/go-reuseport
github.com/pkg/errors
github.com/rivo/tview
github.com/rs/zerolog
github.com/schollz/progressbar/v3
github.com/snksoft/crc
github.com/spf13/cobra
github.com/spf13/viper
github.com/stretchr/testify
github.com/subchen/go-xmldom
github.com/viney-shih/go-lock
golang.org/x/exp
golang.org/x/tools
gopkg.in/yaml.v3

go-serial
This is a package that allows you to read from and write to serial ports in Go.

GoPacket
This library provides packet decoding capabilities for Go.
google 开发packet 项目 fork到了
github.com/gopacket/gopacket 继续更新维护。

还有命令行的GUI项目：
https://github.com/rivo/tview

https://github.com/ajankovic/xdiff
X-Diff is an algorithm that proposes change detection between XML documents by treating them as unordered trees.
命令行使用：
xdiff -left original.xml -right edited.xml

https://github.com/schollz/progressbar
使用代码实现进度条。

https://github.com/spf13/cobra
一个基础的golang命令行项目：
给k8s ， hugo 等项目引用。

3，总结

---

golang 感觉上要是使用其他语言也可以实现和plc 进行数据对接的。
使用golang 进行开发的好处是可以方便、快速的进行数据上报，接口联调。
做边缘计算，做云计算。打造工业化4.0服务。

本文的原文连接是:
https://blog.csdn.net/freewebsys/article/details/108971807