配置 OPC 发布服务器

项目
06/10/2019

重要

当我们更新本文时，请参阅 Azure 工业 IoT 来了解最新内容。

你可以配置 OPC 发布服务器以指定：

要发布的 OPC UA 节点数据更改。
要发布的 OPC UA 事件。
遥测格式。

可以使用配置文件或方法调用来配置 OPC 发布服务器。

使用配置文件

本部分介绍使用配置文件配置 OPC UA 节点发布的选项。

使用配置文件配置发布数据更改

配置要发布的 OPC UA 节点的最简单方法是使用配置文件。配置文件格式记录在存储库的 publishednodes.json 中。

配置文件语法随时间变化。 OPC 发布服务器仍然读取旧格式，但在继续配置时将其转换为最新格式。

以下示例显示了配置文件的格式：

[
  {
    "EndpointUrl": "opc.tcp://testserver:62541/Quickstarts/ReferenceServer",
    "UseSecurity": true,
    "OpcNodes": [
      {
        "Id": "i=2258",
        "OpcSamplingInterval": 2000,
        "OpcPublishingInterval": 5000,
        "DisplayName": "Current time"
      }
    ]
  }
]

使用配置文件配置发布事件

若要发布 OPC UA 事件，请使用与数据更改相同的配置文件。

以下示例显示如何为 SimpleEvents 服务器生成的事件配置发布。在 OPC Foundation 存储库中可以找到 SimpleEvents 服务器：

[
  {
    "EndpointUrl": "opc.tcp://testserver:62563/Quickstarts/SimpleEventsServer",
    "OpcEvents": [
      {
        "Id": "i=2253",
        "DisplayName": "SimpleEventServerEvents",
        "SelectClauses": [
          {
            "TypeId": "i=2041",
            "BrowsePaths": [
              "EventId"
            ]
          },
          {
            "TypeId": "i=2041",
            "BrowsePaths": [
              "Message"
            ]
          },
          {
            "TypeId": "nsu=http://opcfoundation.org/Quickstarts/SimpleEvents;i=235",
            "BrowsePaths": [
              "/2:CycleId"
            ]
          },
          {
            "TypeId": "nsu=http://opcfoundation.org/Quickstarts/SimpleEvents;i=235",
            "BrowsePaths": [
              "/2:CurrentStep"
            ]
          }
        ],
        "WhereClause": [
          {
            "Operator": "OfType",
            "Operands": [
              {
                "Literal": "ns=2;i=235"
              }
            ]
          }
        ]
      }
    ]
  }
]

使用方法调用

本部分介绍可用于配置 OPC 发布服务器的方法调用。

使用 OPC UA 方法调用进行配置

OPC 发布服务器包括一个 OPC UA 服务器，在 62222 端口上可以访问该服务器。如果主机名是“发布服务器”，则终结点 URI 是：opc.tcp://publisher:62222/UA/Publisher。

此终结点公开以下四种方法：

PublishNode
UnpublishNode
GetPublishedNodes
IoT HubDirectMethod

使用 Azure IoT 中心直接方法调用进行配置

OPC 发布服务器实现以下 Azure IoT 中心直接方法调用：

PublishNodes
UnpublishNodes
UnpublishAllNodes
GetConfiguredEndpoints
GetConfiguredNodesOnEndpoint
GetDiagnosticInfo
GetDiagnosticLog
GetDiagnosticStartupLog
ExitApplication
GetInfo

方法请求和响应的 JSON 有效负载的格式在 opcpublisher/HubMethodModel.cs 中定义。

如果对模块调用一个未知的方法，它会用一个字符串来响应，表示该方法无法实现。可以调用一种未知方法作为对模块执行 Ping 操作的方法。

配置用于身份验证的用户名和密码

通过 IoT 中心直接方法调用可以设置身份验证模式。有效负载必须包含 OpcAuthenticationMode 属性以及用户名和密码：

{
    "EndpointUrl": "<Url of the endpoint to set authentication settings>",
    "OpcAuthenticationMode": "UsernamePassword",
    "Username": "<Username>",
    "Password": "<Password>"
    ...
}

密码由 IoT 中心工作负载客户端加密，并存储在发布服务器的配置中。若要将身份验证更改回匿名，请使用具有以下有效负载的方法：

{
    "EndpointUrl": "<Url of the endpoint to set authentication settings>",
    "OpcAuthenticationMode": "Anonymous"
    ...
}

如果有效负载种未设置 OpcAuthenticationMode 属性，则配置中的身份验证设置保持不变。

配置遥测发布

OPC 发布服务器收到发布节点中的值更改通知后，会生成一条 JSON 格式的消息，并将其发送到 IoT 中心。

你可以使用配置文件配置此 JSON 格式消息的内容。如果没有使用 --tc 选项指定配置文件，则使用与连接的工厂解决方案加速器兼容的默认配置。

如果将 OPC 发布服务器配置为批处理消息，那么它们将作为有效的 JSON 数组进行发送。

遥测数据的来源如下：

节点的 OPC 发布服务器节点配置
OPC 发布服务器收到其通知的 OPC UA 堆栈的 MonitoredItem 对象。
传递给此通知的参数，其中提供有关数据值更改的详细信息。

输入到 JSON 格式消息中的遥测数据是这些对象的精选重要属性。如果需要更多属性，则需要更改 OPC 发布服务器代码库。

此配置文件的语法如下所示：

// The configuration settings file consists of two objects:
// 1) The 'Defaults' object, which defines defaults for the telemetry configuration
// 2) An array 'EndpointSpecific' of endpoint specific configuration
// Both objects are optional and if they are not specified, then publisher uses
// its internal default configuration, which generates telemetry messages compatible
// with the Microsoft Connected factory Preconfigured Solution (https://github.com/Azure/azure-iot-connected-factory).

// A JSON telemetry message for Connected factory looks like:
//  {
//      "NodeId": "i=2058",
//      "ApplicationUri": "urn:myopcserver",
//      "DisplayName": "CurrentTime",
//      "Value": {
//          "Value": "10.11.2017 14:03:17",
//          "SourceTimestamp": "2017-11-10T14:03:17Z"
//      }
//  }

// The 'Defaults' object in the sample below, are similar to what publisher is
// using as its internal default telemetry configuration.
{
    "Defaults": {
        // The first two properties ('EndpointUrl' and 'NodeId' are configuring data
        // taken from the OpcPublisher node configuration.
        "EndpointUrl": {

            // The following three properties can be used to configure the 'EndpointUrl'
            // property in the JSON message send by publisher to IoT Hub.

            // Publish controls if the property should be part of the JSON message at all.
            "Publish": false,

            // Pattern is a regular expression, which is applied to the actual value of the
            // property (here 'EndpointUrl').
            // If this key is omitted (which is the default), then no regex matching is done
            // at all, which improves performance.
            // If the key is used you need to define groups in the regular expression.
            // Publisher applies the regular expression and then concatenates all groups
            // found and use the resulting string as the value in the JSON message to
            //sent to IoT Hub.
            // This example mimics the default behaviour and defines a group,
            // which matches the conplete value:
            "Pattern": "(.*)",
            // Here some more exaples for 'Pattern' values and the generated result:
            // "Pattern": "i=(.*)"
            // defined for Defaults.NodeId.Pattern, will generate for the above sample
            // a 'NodeId' value of '2058'to be sent by publisher
            // "Pattern": "(i)=(.*)"
            // defined for Defaults.NodeId.Pattern, will generate for the above sample
            // a 'NodeId' value of 'i2058' to be sent by publisher

            // Name allows you to use a shorter string as property name in the JSON message
            // sent by publisher. By default the property name is unchanged and will be
            // here 'EndpointUrl'.
            // The 'Name' property can only be set in the 'Defaults' object to ensure
            // all messages from publisher sent to IoT Hub have a similar layout.
            "Name": "EndpointUrl"

        },
        "NodeId": {
            "Publish": true,

            // If you set Defaults.NodeId.Name to "ni", then the "NodeId" key/value pair
            // (from the above example) will change to:
            //      "ni": "i=2058",
            "Name": "NodeId"
        },

        // The MonitoredItem object is configuring the data taken from the MonitoredItem
        // OPC UA object for published nodes.
        "MonitoredItem": {

            // If you set the Defaults.MonitoredItem.Flat to 'false', then a
            // 'MonitoredItem' object will appear, which contains 'ApplicationUri'
            // and 'DisplayNode' proerties:
            //      "NodeId": "i=2058",
            //      "MonitoredItem": {
            //          "ApplicationUri": "urn:myopcserver",
            //          "DisplayName": "CurrentTime",
            //      }
            // The 'Flat' property can only be used in the 'MonitoredItem' and
            // 'Value' objects of the 'Defaults' object and will be used
            // for all JSON messages sent by publisher.
            "Flat": true,

            "ApplicationUri": {
                "Publish": true,
                "Name": "ApplicationUri"
            },
            "DisplayName": {
                "Publish": true,
                "Name": "DisplayName"
            }
        },
        // The Value object is configuring the properties taken from the event object
        // the OPC UA stack provided in the value change notification event.
        "Value": {
            // If you set the Defaults.Value.Flat to 'true', then the 'Value'
            // object will disappear completely and the 'Value' and 'SourceTimestamp'
            // members won't be nested:
            //      "DisplayName": "CurrentTime",
            //      "Value": "10.11.2017 14:03:17",
            //      "SourceTimestamp": "2017-11-10T14:03:17Z"
            // The 'Flat' property can only be used for the 'MonitoredItem' and 'Value'
            // objects of the 'Defaults' object and will be used for all
            // messages sent by publisher.
            "Flat": false,

            "Value": {
                "Publish": true,
                "Name": "Value"
            },
            "SourceTimestamp": {
                "Publish": true,
                "Name": "SourceTimestamp"
            },
            // 'StatusCode' is the 32 bit OPC UA status code
            "StatusCode": {
                "Publish": false,
                "Name": "StatusCode"
                // 'Pattern' is ignored for the 'StatusCode' value
            },
            // 'Status' is the symbolic name of 'StatusCode'
            "Status": {
                "Publish": false,
                "Name": "Status"
            }
        }
    },

    // The next object allows to configure 'Publish' and 'Pattern' for specific
    // endpoint URLs. Those will overwrite the ones specified in the 'Defaults' object
    // or the defaults used by publisher.
    // It is not allowed to specify 'Name' and 'Flat' properties in this object.
    "EndpointSpecific": [
        // The following shows how a endpoint specific configuration can look like:
        {
            // 'ForEndpointUrl' allows to configure for which OPC UA server this
            // object applies and is a required property for all objects in the
            // 'EndpointSpecific' array.
            // The value of 'ForEndpointUrl' must be an 'EndpointUrl' configured in
            // the publishednodes.json confguration file.
            "ForEndpointUrl": "opc.tcp://<your_opcua_server>:<your_opcua_server_port>/<your_opcua_server_path>",
            "EndpointUrl": {
                // We overwrite the default behaviour and publish the
                // endpoint URL in this case.
                "Publish": true,
                // We are only interested in the URL part following the 'opc.tcp://' prefix
                // and define a group matching this.
                "Pattern": "opc.tcp://(.*)"
            },
            "NodeId": {
                // We are not interested in the configured 'NodeId' value, 
                // so we do not publish it.
                "Publish": false
                // No 'Pattern' key is specified here, so the 'NodeId' value will be
                // taken as specified in the publishednodes configuration file.
            },
            "MonitoredItem": {
                "ApplicationUri": {
                    // We already publish the endpoint URL, so we do not want
                    // the ApplicationUri of the MonitoredItem to be published.
                    "Publish": false
                },
                "DisplayName": {
                    "Publish": true
                }
            },
            "Value": {
                "Value": {
                    // The value of the node is important for us, everything else we
                    // are not interested in to keep the data ingest as small as possible.
                    "Publish": true
                },
                "SourceTimestamp": {
                    "Publish": false
                },
                "StatusCode": {
                    "Publish": false
                },
                "Status": {
                    "Publish": false
                }
            }
        }
    ]
}

后续步骤

现在你已了解如何配置 OPC 发布服务器，建议下一步是了解如何运行 OPC 发布服务器。

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