Client settings parameters

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Last UpdatedJun 26, 2025
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The following parameters are available for configuring OPC UA client settings:

Note: All intervals, delays, and timeouts require the string to be formatted like this: [d:]h:mm:ss[.FFFFFFF] where the items in brackets are optional. d = days, h = hours, mm = minutes, ss = seconds, F = fractional portion of a second. Example: "05:07:10:40.150" for 5 days, 7 hours, 10 minutes, 40 seconds, and .150 seconds.

Data items parameters

The following table lists data items parameters for client settings:

Parameter	Required	Type	Description
maxBrowseReferencesToReturn	Optional	integer	Maximum number of references returned from browse call. Minimum value: 0 Maximum value: 4294967295 Default value: 0
browseBlockSize	Optional	integer	Maximum number of nodes to browse in one call. Minimum value: 1 Maximum value: 4294967295 Default value: 10
readBlockSize	Optional	integer	Maximum number of variables to read in one call. Minimum value: 0 Maximum value: 4294967295 Default value: 1000
reconnectDelay	Optional	TimeSpan	Delay between reconnection attempts.* Does not apply to the initial connection, only reconnections. Allowed value: cannot be negative Default value: 0:00:30
recreateSubscriptionDelay	Optional	TimeSpan	Delay between successful reconnection and subsequent subscription recreation.* Allowed value: cannot be negative Default value: 0:00:10
sessionRequestTimeout	Optional	TimeSpan	Default request timeout.* Allowed value: greater than 00:00:05 Default value: 0:02:00
connectionTimeout	Optional	TimeSpan	Connection timeout.* Allowed value: greater than 00:00:05 Default value: 0:00:30
sessionAllowInsecureCredentials	Optional	boolean	When set to true credentials can be communicated over unencrypted channel. Allowed value: true or false Default value: false
sessionMaxOperationsPerRequest	Optional	integer	Default maximum operation per request. Minimum value: 0 Maximum value: 4294967295 Default value: 1000
browseTimeout	Optional	TimeSpan	Browse operation timeout.* Allowed value: greater than 00:00:05 Default value: 0:01:00
readTimeout	Optional	TimeSpan	Read operation timeout.* Allowed value: greater than 00:00:05 Default value: 0:00:30
maxMonitoredItemsPerCall	Optional	integer	Maximum number of monitored items that can be added to subscription in one call. Minimum value: 1 Maximum value: 4294967295 Default value: 1000
maxNotificationsPerPublish	Optional	integer	Maximum notification messages in one publish message. Minimum value: 0 Maximum value: 4294967295 Default value: 0
publishingInterval	Optional	TimeSpan	Publishing interval of the subscription.* Allowed value: cannot be negative Default value: 0:00:01
createMonitoredItemsTimeout	Optional	TimeSpan	Create monitored items timeout.* Allowed value: greater than 00:00:05 Default value: 0:00:30
samplingInterval	Optional	TimeSpan	Sampling interval for monitored items created by the adapter.* Allowed value: cannot be negative Default value: 0:00:00:5
monitoredItemDataChangeTrigger	Optional	string	Determines on what conditions a subscription sends new values to the adapter. Allowed values: Status, StatusValue, StatusValueTimestamp Default value: StatusValue
monitoredItemQueueSize	Optional	integer	Controls the size of the per-item publishing queue on the OPC UA server. This value must be set large enough to hold the amount of samples expected within a publishing interval. For Hot server failover, set this large enough to buffer enough samples during a failover event so that data will not be lost. Minimum value: 1 Maximum value: 4294967295 Default value: 2
maxInternalQueueSize	Optional	integer	Maximum number of items that can be in the adapter internal queue. Minimum value: 1000 Maximum value: 2147483647 Default value: 500000
historyReadBlockSize	Optional	integer	Maximum number of nodes for history to read in one call. Minimum value: 1 Maximum value: 4294967295 Default value: 10
historyReadTimeout	Optional	TimeSpan	History read operation timeout.* Allowed value: greater than 00:00:05 Default value: 0:01:00
operationTimeout	Optional	TimeSpan	Maximum Timeout for all other operations related timeouts, except session requests. Allowed value: greater than or equal 00:00:05 Default value: 0:04:00

* Note: You can also specify timespans as numbers in seconds. For example, "reconnectDelay": 25 specifies 25 seconds, or "reconnectDelay": 125.5 specifies 2 minutes and 5.5 seconds.

Event Type parameters

The following table lists event type parameters for client settings:

Parameter	Required	Type	Description
childEventPropertyLevel	Optional	integer	Maximum level of child event properties to discover in event type discoveries. Minimum value: 0 Maximum value: 4294967295 Default value: 1 Note: This parameter only applies to the Events discovery operation. The adapter's data selection can be manually configured with child event properties up to any level.
eventTypeMonitoredItemQueueSize	Optional	integer	Controls the size of the per-item publishing queue for event monitored items on the OPC UA server. This value must be set large enough to hold the number of samples expected within a publishing interval. Minimum value: 0 Maximum value: 4294967295 Default value: 0 (Server's default queue size for event notifications)
minimumEventSeverity	Optional	integer	This value determines the minimum number of events sent. If the value is set to 0, all events with a Severity below the value set for the maximumEventSecurity will be sent. Allowed values: 0 to 999 Default values: 0
maximumEventSeverity	Optional	integer	This value determines the maximum number of events sent. If the value is set to 1000, all events with a Severity above the value set for the minimumEventSecurity will be sent. Allowed values: 1 to 1000 Default values: 1000
eventStringDelimiter	Optional	string	Delimiter for event fields in the egress string. Allowed values: “\|”, “;”,“-”, “,” Default values: "\|"
includeEventPropertyName	Optional	boolean	When set to true, the event property names are included with values. Allowed values: true or false Default values: false

AVEVA™ Adapter for OPC UA