UE4中實現OPC UA Client來控制PLC

緣由與介紹
  OPC Foundation
  OPC (Open Platform Communications)
  OPC UA

實作參考
  Labview控制PLC使用OPC
  商業授權方案 - LabView + LabVIEW OPC UA Toolkit
  Qt OPC UA

open62541實現 (OPC UA C++ Library)
  open62541 - github
  open62541 - documentation

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專案說明
本案硬體需與UE4連動，使用OPC來管理，透過PLC去控制，將open62541 (OPC UA C++  Library) 整理成UE4 plugin，可直接在UE4中直接使用 blueprint function library 呼叫方法來讀取、寫入PLC中的數值。

  硬體端負責工作：硬體與相關感測器整合、PLC串接與控制、建立OPC Server
  軟體端負責工作：建立OPC Client並整合至UE4，可讀取/寫入PLC中的數值

已實現方法
  UA Client Connect
  UA Client ReadValueAttribute
  UA Client WriteValueAttribute
  UA Client Disconnect

	// Copyright 1998-2017 Epic Games, Inc. All Rights Reserved.
	#pragma once
	#include "OpcUaClientBPLibrary.h"
	#include "OpcUaClient.h"
	#include "open62541.h"
	static UA_Client *client;
	UOpcUaClientBPLibrary::UOpcUaClientBPLibrary(const FObjectInitializer& ObjectInitializer)
	: Super(ObjectInitializer)
	{
	}
	bool UOpcUaClientBPLibrary::UA_Client_connect_open62541(FString endpointUrl)
	{
	// Create a client and connect
	client = UA_Client_new();
	UA_ClientConfig_setDefault(UA_Client_getConfig(client));
	UA_StatusCode status = UA_Client_connect(client, TCHAR_TO_UTF8(*endpointUrl));
	if (status != UA_STATUSCODE_GOOD) {
	UA_Client_delete(client);
	return false;
	}
	return true;
	}
	float UOpcUaClientBPLibrary::UA_Client_readValueAttribute_open62541(FString nodeId)
	{
	if (!client) return -2;
	UA_Variant value; /* Variants can hold scalar values and arrays of any type */
	UA_Variant_init(&value);
	UA_StatusCode status = UA_Client_readValueAttribute(client, UA_NODEID_STRING(1, TCHAR_TO_UTF8(*nodeId)), &value);
	if (status == UA_STATUSCODE_GOOD &&
	UA_Variant_hasScalarType(&value, &UA_TYPES[UA_TYPES_FLOAT])) {
	return *(UA_Float*)value.data;
	}
	return -1;
	}
	bool UOpcUaClientBPLibrary::UA_Client_writeValueAttribute_open62541(FString nodeId, float newValue)
	{
	if (!client) return false;
	UA_Variant value;
	UA_Variant_setScalar(&value, &newValue, &UA_TYPES[UA_TYPES_FLOAT]);
	UA_StatusCode status = UA_Client_writeValueAttribute(client, UA_NODEID_STRING(1, TCHAR_TO_UTF8(*nodeId)), &value);
	if (status == UA_STATUSCODE_GOOD &&
	UA_Variant_hasScalarType(&value, &UA_TYPES[UA_TYPES_FLOAT])) {
	return true;
	}
	return false;
	}
	bool UOpcUaClientBPLibrary::UA_Client_disconnect_open62541()
	{
	UA_Client_delete(client);
	return true;
	}

view raw OpcUaClientBPLibrary.cpp hosted with ❤ by GitHub

	// Copyright 1998-2017 Epic Games, Inc. All Rights Reserved.
	#pragma once
	#include "Kismet/BlueprintFunctionLibrary.h"
	#include "OpcUaClientBPLibrary.generated.h"
	/*
	* Function library class.
	* Each function in it is expected to be static and represents blueprint node that can be called in any blueprint.
	*
	* When declaring function you can define metadata for the node. Key function specifiers will be BlueprintPure and BlueprintCallable.
	* BlueprintPure - means the function does not affect the owning object in any way and thus creates a node without Exec pins.
	* BlueprintCallable - makes a function which can be executed in Blueprints - Thus it has Exec pins.
	* DisplayName - full name of the node, shown when you mouse over the node and in the blueprint drop down menu.
	* Its lets you name the node using characters not allowed in C++ function names.
	* CompactNodeTitle - the word(s) that appear on the node.
	* Keywords - the list of keywords that helps you to find node when you search for it using Blueprint drop-down menu.
	* Good example is "Print String" node which you can find also by using keyword "log".
	* Category - the category your node will be under in the Blueprint drop-down menu.
	*
	* For more info on custom blueprint nodes visit documentation:
	* https://wiki.unrealengine.com/Custom_Blueprint_Node_Creation
	*/
	UCLASS()
	class UOpcUaClientBPLibrary : public UBlueprintFunctionLibrary
	{
	GENERATED_UCLASS_BODY()
	/**
	* Connect to OPC UA Server.
	* @param endpointUrl
	* @return true if the connect success.
	*/
	UFUNCTION(BlueprintCallable, meta = (DisplayName = "UA Client Connect", Keywords = "Connect to OPC UA Server"), Category = "OPC UA Client")
	static bool UA_Client_connect_open62541(FString endpointUrl);
	/**
	* Read the value attribute of the node.
	* @param nodeId
	* @return value attribute of the node
	*/
	UFUNCTION(BlueprintCallable, meta = (DisplayName = "UA Client ReadValueAttribute", Keywords = "Read the value attribute of the node"), Category = "OPC UA Client")
	static float UA_Client_readValueAttribute_open62541(FString nodeId);
	/**
	* Write the value attribute of the node.
	* @param nodeId
	* @param newValue
	* @return true if the value attribute writes success.
	*/
	UFUNCTION(BlueprintCallable, meta = (DisplayName = "UA Client WriteValueAttribute", Keywords = "Write the value attribute of the node"), Category = "OPC UA Client")
	static bool UA_Client_writeValueAttribute_open62541(FString nodeId, float newValue);
	/**
	* Disconnects the client.
	* @return true if dissconnected.
	*/
	UFUNCTION(BlueprintCallable, meta = (DisplayName = "UA Client Disconnect", Keywords = "Disconnects the client."), Category = "OPC UA Client")
	static bool UA_Client_dissconnect_open62541();
	};

view raw OpcUaClientBPLibrary.h hosted with ❤ by GitHub