CDP Studio Documentation

Protocols - OPC UA I/O
OPC-UA-Adapter
5.0.0

OPC-UA-Adapter

The CDP OPC-UA-Adapter is a CDP module that allows remote clients to connect to running CDP applications via the OPC UA protocol, providing access to all objects and parameters of the CDP application, just like CDP by default does it via the StudioAPI protocol.

After adding an OPC-UA-Adapter to the CDP application you can use any OPC UA client (like UaExpert) or any OPC UA tool or library (like opcua-asyncio for Python) to connect and view or change any value in the system.

OPC-UA-Adapter has support for user authentication plus transport encryption and signing, so it can be used safely over insecure networks (like the Internet).

OPC-UA-Adapter is very simple to use. You only have to add the adapter to your CDP application and it is working without any configuration, with default settings.

Note: The OPC-UA-Adapter is a licensed feature. See the CDP Runtime License manual for more information.

OPC-UA-Adapter has the following configuration properties:

Property	Description
EndpointInterface<string>	Interface name (from CDP Application configuration) for the adapter to listen on. Set empty to listen on all interfaces. Defaults to ETH0.
EndpointPort<unsigned short>	TCP port for the adapter to listen on. Defaults to 4840.
SecurityMode<string>	OPC UA message security mode to use. Choose between: None - no security (adapter default setting) Sign - all messages are digitally signed but not encrypted Sign&Encrypt - all messages are digitally signed and encrypted (best security)
SecurityPolicy<string>	OPC UA security policy to use, when SecurityMode other than None is selected. Choose between: Aes256_Sha256_RsaPss - the most secure option for modern systems requiring the highest security and performance (adapter default setting). Policy is described in detail at http://opcfoundation.org/UA/SecurityPolicy#Aes256_Sha256_RsaPss Aes128_Sha256_RsaOaep - a balanced option for modern systems requiring moderate security and performance. Policy is described in detail at http://opcfoundation.org/UA/SecurityPolicy#Aes128_Sha256_RsaOaep Basic256Sha256 - suitable for systems requiring robust security, such as industrial automation or sensitive data applications. Policy is described in detail at http://opcfoundation.org/UA/SecurityPolicy#Basic256Sha256 Basic256 - this policy is no longer considered as secure and therefore should only be used in rare circumstances, when client does not support more secure policies. Policy is described in detail at http://opcfoundation.org/UA/SecurityPolicy#Basic256 Basic128Rsa15 - this policy is no longer considered as secure and therefore should only be used in rare circumstances, when client does not support more secure policies. Policy is described in detail at http://opcfoundation.org/UA/SecurityPolicy#Basic128Rsa15
TLSServerCertFile<string>	Adapter TLS key certificate file name. Must be filled when SecurityMode other than None is selected. See also OPC UA TLS certificate setup.
TLSServerKeyFile<string>	Adapter TLS key file name. Must be filled when SecurityMode other than None is selected. See also OPC UA TLS certificate setup.
TLSAllowURIMismatch<bool>	Can be set to true to allow connection from clients with TLS certificates that do not match with their application URI. See also OPC UA TLS certificate setup.
AnonymousAccessLevel<string>	Access level flags for clients logging in without credentials (using anonymous mode). The following OPC UA access flags can be set: R - Allow read access for anonymous clients W - Allow write access for anonymous clients h - Allow history read access for anonymous clients H - Allow history write access for anonymous clients C - Allow semantic change for anonymous clients s - Allow status write for anonymous clients T - Allow timestamp write for anonymous clients
EndpointAppURI<string>	OPC UA namespace URI for the application. If left empty, adapter component full name is used.
EndpointAppName<string>	Description for the application to be advertised. If left empty, CDP component name is used.

An unlimited number of AllowedClient sub-elements can be added to OPC-UA-Adapter to configure allowed clients and their credentials. Each AllowedClient has the following configuration properties:

Property	Description
Name<string>	OPC UA client username
Password<string>	OPC UA client password
TLSClientCertFile<string>	OPC UA client TLS certificate to use for authentication. Can be left empty if SecurityMode None is used.
AccessLevel<string>	Access level flags for this OPC UA client. The following OPC UA access flags can be set: R - Allow read access for this client W - Allow write access for this client h - Allow history read access for this client H - Allow history write access for this client C - Allow semantic change for this client s - Allow status write for this client T - Allow timestamp write for this client

Note: For strongest authentication use AllowedClients that have both password and certificate authentication.

Adapter state can be observed at runtime via these read-only properties:

EndpointURL<string>	Endpoint URL. Is automatically composed from protocol, listen ip and port.
EndpointProtocol<string>	OPC UA protocol to use. Currently only opc.tcp (binary) protocol is supported.
CurrentState<string>	State of the adapter. Can be Online or Offline. When a problem is detected at startup, the adapter is offline.

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