.. _vnx.opc_ua.Server:

vnx.opc_ua.Server
=================

.. cpp:namespace:: vnx::opc_ua::Server

Module
------

The `vnx.opc_ua.Server` module provides a OPC-UA server to interface with the running process.

Depending on the configuration different modules and topics are offered on the OPC-UA interface.


Options
-------

.. cpp:member:: string custom_hostname

	An optional custom host name.

.. cpp:member:: uint port = 4840

	The port number the server binds to.

.. cpp:member:: set<string> export_services
	
	List of modues to offer on the OPC-UA interface as objects.
	
.. cpp:member:: set<string> export_topics
	
	List of topics to offer on the OPC-UA interface as variables.

.. cpp:member:: string certificate_file

	Optional path to a server certificate file (DER format).

.. cpp:member:: string private_key_file

	Optional path to a server private key file (DER format).

.. cpp:member:: string application_name = "pilot.opc_ua.server"

	Optional application name.

.. cpp:member:: string application_uri = "urn:open62541.server.application"

	Must match the URI in the certificate.

.. cpp:member:: vector<string> trust_list

	Client certificate trust files (CRL format).
	This only has an effect if a server certificate is configured.
	If the list is empty, any certificate is accepted.

.. cpp:member:: bool add_insecure_discovery = true

	Allow discovery with security policy ``NONE`` even if not configured.
	This is necessary if you want a secure server (i.e. no ``NONE`` policy)
	that can still be discovered by a client.
	If security policy ``NONE`` `is` configured, this option has no effect.

.. cpp:member:: vector<security_policy_e> security_policies

	A list of the security/encryption policies to provide.
	Most policies require a certificate and a private key.
	See :ref:`vnx.opc_ua.security_policy_e`

.. cpp:member:: vector<pair<node_id_t, Variant>> variables

	A list of writable variables to create.
	For each variable a :ref:`vnx.opc_ua.node_id_t` and an initial value is expected.
	The type of the variable is guessed from the initial value.

.. cpp:member:: map<string, node_id_t> error_variables

	Create optional error variables for exported services where error messages
	from their method calls are published. This can be necessary, since OPC-UA
	does not support returning error messages.

.. cpp:member:: bool use_authentication

	If to require authentication from clients.
	If set to ``false``, any connected user has full permissions.

.. cpp:member:: bool allow_anonymous_access

	Allow access without authentication.

.. cpp:member:: string default_access

	Default access level for anonymous clients, see :ref:`users`.
	This only has an effect if ``use_authentication`` is set to ``true``.