OPC-UA-Subscriber

Edit online

Use the OPC-UA-Subscriber node to connect App Connect Enterprise applications to an OPC UA server.

Using OPC-UA-Subscriber node in a message flow

Use the OPC-UA-Subscriber node to consume network messages from message-oriented middleware (MOM) infrastructures and protocols, like UADP with IP unicast and multicast, on which the publisher is publishing the network messages.

The OPC-UA Subscriber node is driven by a File Output node. The OPC-UA Subscriber node connects to the File Output node to process the subscriber properties and output them as an XML message that contains the subscriber properties along with messages that are received from the publisher. For more information, see App Connect for Manufacturing XML schema.

Terminals

The OPC-UA-Subscriber node terminals are described in the following table.
Terminal Description
Failure The output terminal to which a message is routed if an error occurs during processing.
Out The output terminal to which any successful client item readings are sent.
Catch The output terminal to which the message is routed if an exception is thrown downstream and caught by this node. Exceptions are caught only if this terminal is attached.

Properties

The following tables describe the properties for the OPC-UA-Subscriber node.
Note: A mandatory property is marked with an asterisk and a configurable property allows you to edit when you add the message flow to the broker archive (BAR) file.
Important: Secure connection is recommended which can be enabled by using the following configurations on The Properties view of the OPC-UA-Subscriber node.
  • The value of the Message Security Mode property as either SignAndEncrypt or Sign.
  • The value of the Message Security Policy property as either AES256CTR or AES128CTR.
Nonsecure connection is also available for development and testing purpose.

 Basic tab properties 

Table 1. Mapping the properties for the OPC-UA-Subsciber
Field Subfields Description OPC-UA-Subsciber Mandatory Configurable
Protocol N/A

The protocol that is used for publishing messages.

Supported value is either UDP or MQTT.

 ✓ Yes No
Message Encoding N/A

The message encoding that is used while publishing the message.

Supported value is either UADP(Optimized Binary) or JSON.

JSON encoding is supported only when the value of the Protocol property is MQTT.

 ✓ Yes No
Message Security Mode N/A

Security mode and security policies are used in combination to secure endpoints.

The mode can be set to None, Sign, or SignAndEncrypt.

By default, the value is set to SignAndEncrypt.

This property is only supported when the value of the Message Encoding property is UADP.

 ✓ Yes No
Message Security Policy N/A

Security mode and security policies are used in combination to secure endpoints.

The mode can be set to None, AES128CTR, or AES256CTR.

By default, the value is set to AES256CTR.

This property is only supported when the value of the Message Encoding property is UADP.

 ✓ Yes No
Publisher URL N/A

The URL of the publisher that publishes the messages.

Specify the IP address and hostname. For example, ip_address:hostname.

 ✓ Yes No
Publisher ID N/A

Specifies the publisher from whom the network messages will be received.

The Publisher ID is a unique identifier for each flow running on an integration server.

Note: The valid data types are UInteger and String.
 ✓ Yes No
Dataset Items Writer Group ID

The identifier for a writer group. This value is unique across all writer groups for a publisher ID.

The valid values are from 0 to 65535. The value 0 is defined as a null value.

 ✓ Yes Yes
Dataset Writer ID

The unique identifier for the dataset writer for a published dataset. This identifier is used to select the dataset messages for a published dataset for the subscriber.

This value is a UInt16 data type value, and it is unique across all dataset writers for a publisher ID.

The valid values are from 0 to 65535. The value 0 is defined as a null value.

 ✓ Yes Yes
Subscriber Topic Unique name of the data stream produced by the Writer Group within a Message Oriented Middleware. Also known as Queue name.

This property is only supported when the value of the Message Encoding property is MQTT.

 ✓ MQTT Protocol Yes
Metadata File Name

The file that contains information on a dataset, such as the names of the optional fields and the data types of the mandatory fields

Specify the absolute path of this file in the server.conf.yaml file.

Note: This property is not applicable for the App Connect for Manufacturing13.0.0.1 release.
 ✓ Yes Yes
For more information, see PubSub Overview.