OPC UA Server Configuration Settings

To allow an OPC UA Client to access CODESYS variables, you need to configure the OPC UA Server. This is done in the configuration file CODESYSControl.cfg which is stored in the installation directory of CODESYS in the \GatewayPLC directory.

Example 8. Sample configuration

[CmpOPCUAServer]
NetworkAdapter="eth0"

Table 5.

Key	Default Value	Runtime System (and higher)	Description
`MaxNodesPerRead`	100	V3.5 SP 17	Defines the number of nodes which are accepted by the corresponding OPC UA service. The `OperationLimits` of the OPC UA address space are also taken into account. For more details, see the OPC UA specification.
`MaxNodesPerHistoryReadData`	100	V3.5 SP 17
`MaxNodesPerHistoryReadEvents`	100	V3.5 SP 17
`MaxNodesPerWrite`	100	V3.5 SP 17
`MaxNodesPerHistoryUpdateData`	100	V3.5 SP 17
`MaxNodesPerMethodCall`	100	V3.5 SP 17
`MaxNodesPerBrowse`	100	V3.5 SP 17
`MaxNodesPerRegisterNodes`	100	V3.5 SP 17
`MaxNodesPerTranslateBrowsePathsToNodeIds`	100	V3.5 SP 17
`MaxNodesPerNodeManagement`	100	V3.5 SP 17
`NetWorkAdapter`		V3.5 SP7	Configures the network adapter which should be used by the OPC UA Server. Example: "eth0", "Ethernet Adapter" If a configuration does not exist, then all network adapters with a valid IP address are used.
`NetworkPort`	4840	V3.5 SP7	Configures the port used by the OPC UA Server.
`UseLoopback`	1	V3.5 SP7 Patch 2	Adds the loopback adapter as an OPC UA endpoint if it is missing in the configuration.
`AdapterUpdateRate`	5000	V3.5 SP15	Defines the interval in which the OPC UA Server reacts to changed network adapters. Ports are opened or closed depending on whether a network adapter is reconnected or has lost the connection.
`ItemMinSamplingRate`	100	V3.5 SP15	Defines the minimum sampling rate of the monitored variables (in ms).
`NumOfWorkerTasks`	-1	V3.5 SP16	Configures the number of worker tasks to be created. The default value -1 generates between 1 and (<number of CPU cores> - 1) worker tasks. The worker tasks are responsible for sampling the monitored variables.
`WorkerTasksDynamic`	2	V3.5 SP18	Defines whether OPC UA Server worker tasks should be created dynamically depending on the load or statically in order to optimize the start behavior: 0: Static 1: Generate, but pause and resume depending on the load 2: Generate and end depending on the load
`SchedulerResolution`	1	V3.5 SP17	Configures the resolution of the scheduler of the OPC UA Server (in ms)
`SessionsMax`	100	V3.5 SP17	Maximum possible number of sessions (only effective if greater than the start size). A session is an online connection of a client.
`SecureChannelsMax`	50	V3.5 SP19	Maximum number of communication channels supported by the server. Some channels may contain multiple sessions. If the number exceeds the value `SOCKET_FDSET_SIZE` - <number of open ports>, then not all channels can be used.
`ContinuationPointsPerSessionMax`	50	V3.5 SP17	Maximum possible continuation points per session. The parameter is required so that the client can subsequently browse for information.
`PublishRequestsPerSessionMax`	Unlimited	V3.5 SP17	Maximum possible publication requests per session
`SubscriptionsPerSessionMax`	Unlimited	V3.5 SP17	Maximum possible number of subscriptions per session
`PublishNotificationsMax`	Unlimited	V3.5 SP17	Maximum number of possible publication messages