Appendix B: Configuration File Edits

Upon startup of the Server, a default configuration file is created, C:\ProgramData\AutoSol\Communication Manager\7\asiOpcUa.Config.xml. The settings contained in the file can be edited using the ACM Monitor application, as described in the Configuration section of this document. Normally, manual editing of the file is not needed. The exception would be to change the default values of the Transport Quotas, message queue sizes, or message sizes to fine tune a large system. The table below details the elements of the configuration file that can be manually edited.

If an editing mistake is made and the Server will not load the configuration file, delete the configuration file and restart the Server. A new default file will be created.

This configuration file should be part of your system back up plan.

Element	Description	Default
OperationTimeout	The default timeout to use when sending requests.	600000
MaxStringLength	The maximum length of string encoded in a message body.	1048576
MaxByteStringLength	The maximum length of a byte string encoded in a message body.	1048576
MaxArrayLength	The maximum length of an array encoded in a message body.	65535
MaxMessageSize	The maximum length of a message body.	4194304
MaxBufferSize	The maximum size of the buffer to use when sending messages.	65535
ChannelLifetime	The lifetime of a secure channel.	300000
SecurityTokenLifetime	The lifetime of a security token.	3600000
MaxSessionCount	The maximum number of open sessions.	100
MinSessionTimeout	That minimum period of that a session is allowed to remain open without communication from the client (in milliseconds).	10000
MaxSessionTimeout	That maximum period of that a session is allowed to remain open without communication from the client (in milliseconds).	3600000
MaxBrowseContinuationPoints	The maximum number of continuation points used for Browse/BrowseNext operations.	10
MaxQueryContinuationPoints	The maximum number of continuation points used for Query/QueryNext operations.	10
MaxHistoryContinuationPoints	The maximum number of continuation points used for HistoryRead operations.	100
MaxRequestAge	The maximum age of an incoming request (old requests are rejected).	600000
MinPublishingInterval	The minimum publishing interval supported by the server (in milliseconds).	100
MaxPublishingInterval	The maximum publishing interval supported by the server (in milliseconds).	3600000
PublishingResolution	The minimum difference between supported publishing interval (in milliseconds).	50
MaxSubscriptionLifetime	The maximum time a Subscription Lifetime can be set to by the client. The actual Subscription Lifetime used can be a lower value. A subscription is closed when the Subscription Lifetime expires without a client publish.	3600000
MaxMessageQueueSize	The maximum number of publish messages saved in the queue for each subscription. (This number multiplied by MaxNotificationsPerPublish determine the maximum number of items that can be updated from the address space.)	1500
MaxNotificationQueueSize	The maximum number of notifications saved in the queue for each monitored item.	1500
MaxNotificationsPerPublish	The maximum number of notifications per publish message. (This number multiplied by MaxMessageQueueSize determine the maximum number of items that can be updated from the address space.)	1000
MinMetadataSamplingInterval	The minimum sampling interval for metadata.	1000
MinSubscriptionLifetime	The minimum time a Subscription Lifetime can be set to by the client. The actual Subscription Lifetime used can be a higher value.	10000
MaxPublishRequestCount	The max publish request count.	100
MaxSubscriptionCount	The max subscription count.	200
MaxEventQueueSize	The max size of the event queue.	10000
ShutdownDelay	The server shutdown delay.	5
DisableHiResClock	Disables the hi-res clock if the QueryPerformanceCounter does work on a particular machine.	false
MaxNodesPerWrite	The maximum number of nodes that can be written to by a client in one request.	10
TraceMasks	The trace mask used for generating log messages when the log option "OPC UA Stack" is enabled. This value should only be changed at the direction of AUTOSOL support. The value entered can be a summation of the following trace mask values. None - 0; Errors - 1; Information - 2; Stack Trace - 4; Service Calls - 8; Service Details - 16; Operations - 32; Operation Detail - 64; Start/Stop - 128; External System - 256; Security - 512 To enable all trace masks, enter a value of 1023. The default value of 939 represents the summation of the trace mask values Errors, Information, Service Calls, Operations, Start/Stop, External System, and Security.	939

Configuration File Additions

This section describes additions that can be made to the configuration file to support new features not yet in the configuration schema. This is for legacy systems that have not upgraded to the latest version of the OPC UA server and have an outdated configuration file. No guarantee is made that any addition to the file will be supported by the user's current system as functionality depends upon the underlying version of the OPC UA Foundation stack. If the stack does not support the feature, editing the file will have no effect. Make a back up copy of the current configuration file before making edits in the event the server cannot load the schema additions.

Self Signed Certificate Lifetime

When the OPC UA server is first started, it will automatically generate a self-signed application certificate. The default lifetime, before the certificate expires, is 12 months. To modify the certificate lifetime, add the following section to the configuration file. Note that the addition must be in the Extensions section of the file and must come after the ASIExtensions element.

The value entered for ServerCertificateLifeTime is the number of months the generated certificate will be valid for. Delete the current application certificates from the own/certs and own/private folders of the server's pki store. Stop the OPC UA service and restart. New certificates will be generated.