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Scope: Core (OPC-10000-*) All specs

12 result(s) for ServiceLevel

OPC-10000-1 – OPC Unified Architecture - Part 1: Overview and Concepts

5.4 Redundancy

health of a Server including its ability to Service requests is collectively defined as ServiceLevel . See OPC 10000-5 for a formal definition of ServiceLevel . OPC 10000-4 defines four ... distinct ServiceLevel sub-ranges and example usage
OPC-10000-4 – OPC Unified Architecture - Part 4: Services

6.6.2.2 RedundantServerSet Requirements

NodeIds identical browse paths and structure of the AddressSpace identical logic for setting the ServiceLevel The only Nodes that can differ between Servers in a RedundantServerSet are the Nodes that
OPC-10000-4 – OPC Unified Architecture - Part 4: Services

6.6.2.3.1 Client behaviour

data structures to allow Clients to identify which Servers are in the RedundantServerSet , the ServiceLevel of each Server, and which Server is currently responsible for the Client Session . This information
OPC-10000-4 – OPC Unified Architecture - Part 4: Services

6.6.2.4.2 ServiceLevel

ServiceLevel The ServiceLevel provides information to a Client regarding the health of a Server and its ability to provide data. See OPC 10000-5 for a formal definition for ServiceLevel ... ServiceLevel is a byte with a range of 0 to 255, where the values fall into the sub-ranges defined in Table 105 . The algorithm used by a Server
OPC-10000-4 – OPC Unified Architecture - Part 4: Services

6.6.2.4.3 Load balancing

Servers in the RedundantServerSet can share the load generated by Clients by setting the ServiceLevel in the Healthy sub-range based on the current load. Clients are expected to connect ... Server with the highest ServiceLevel . Clients shall not Failover to a different Server in the RedundantServerSet of Servers as long as the Server is in the Healthy sub-range. This
OPC-10000-4 – OPC Unified Architecture - Part 4: Services

6.6.2.4.4 Server Failover modes

Server connection. Therefore, only a single Server will be able to consume data. The ServiceLevel Variable defined in OPC 10000-5 and the sub-range defined in Table 105 indicates ... ability of the Server to provide its data to the Client . The ServiceLevel of the primary Server will be in the Healthy ServiceLevel sub-range. The ServiceLevel of the available
OPC-10000-4 – OPC Unified Architecture - Part 4: Services

6.6.2.4.5.3 Warm

should connect to one or more Servers in the RedundantServerSet primarily to monitor the ServiceLevel . A Client can connect and create Subscriptions and MonitoredItems on more than one Server ... such as Bad_NoCommunication. The one Active Server can be found by reading the ServiceLevel Variable from all Servers . The Server with the highest ServiceLevel is the Active Server
OPC-10000-4 – OPC Unified Architecture - Part 4: Services

6.6.2.4.5.4 Hot

connect to two or more Servers in the RedundantServerSet and to subscribe to the ServiceLevel variable defined in OPC 10000-5 to find the highest ServiceLevel to achieve load balancing ... issue Service requests such as Browse , Read , Write to the Server with the highest ServiceLevel. Subscription related activities will need to be invoked for each connected Server . Clients have
OPC-10000-4 – OPC Unified Architecture - Part 4: Services

6.6.2.4.5.5 HotAndMirrored

create Sessions with other Servers and maintain the open connections by periodically reading the ServiceLevel . A Client shall not create Subscriptions on the backup Servers for status monitoring (to prevent
OPC-10000-4 – OPC Unified Architecture - Part 4: Services

6.6.5 Manually Forcing Failover

from the RedundantServerSet can be done through a complete shutdown or by setting the ServiceLevel of the Server to Maintenance sub-range. This can be done through a Server specific
OPC-10000-5 – OPC Unified Architecture - Part 5: Information Model

6.3.1 ServerType

Variable UrisVersion VersionTime PropertyType Optional HasComponent Variable ServerStatus 1 ServerStatusDataType ServerStatusType Mandatory HasProperty Variable ServiceLevel Byte PropertyType Mandatory HasProperty Variable Auditing Boolean PropertyType Mandatory HasProperty Variable EstimatedReturnTime DateTime PropertyType Optional ... describe the status of the Server . See 12.10 for a description of its elements. ServiceLevel describes the ability of the Server to provide its data to the Client . The value
OPC-10000-5 – OPC Unified Architecture - Part 5: Information Model

6.3.15 NonTransparentBackupRedundancyType

operating in BACKUP_READY , BACKUP_NOT_READY or PRIMARY_ONLY mode shall use a ServiceLevel in the degraded range. A Server shall use a higher ServiceLevel value for BACKUP_READY