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

15 result(s) for fail-safe

OPC-10000-15 – OPC Unified Architecture - Part 15: Safety

3.1.2.1 fail-safe

fail-safe ability of a system that, by adequate technical or organizational measures, prevents from hazards either deterministically or by reducing the risk to a tolerable measure Note
OPC-10000-15 – OPC Unified Architecture - Part 15: Safety

3.3.1 General conventions

items, technologies, systems, and units ( fail-safe , functional safe). The default data that are used in case of unit failures or errors, are called fail-safe substitute values
OPC-10000-15 – OPC Unified Architecture - Part 15: Safety

5.3 Safety measures

will cease to deliver actual process values to the safety application but will deliver fail-safe substitute values instead. In addition, an indication at the Safety Application Program Interface
OPC-10000-15 – OPC Unified Architecture - Part 15: Safety

5.4 Safety communication layer structure

standard hardware and software. This principle delimits the assessment effort to the "safe transmission functions". The standard transmission system does not require any additional functional safety assessment ... SafetyBaseID (e.g. by configuration). If this expectation is not fulfilled by the SafetyProvider , fail-safe substitute values are delivered to the safety application instead of the received process values
OPC-10000-15 – OPC Unified Architecture - Part 15: Safety

6.2.3.2 OutFlagsType

SafetyConsumer , see OperatorAckProvider in the SAPI of the SafetyProvider , 6.3.3.2 . ActivateFSV 1 Activation of fail-safe values by the safety application at the SafetyProvider , hereby forwarded to the SafetyConsumer
OPC-10000-15 – OPC Unified Architecture - Part 15: Safety

6.3.3.2 SAPI of SafetyProvider

forwarded to the SafetyConsumer , where it can be used to trigger a return from fail-safe substitute values ( FSV ) to actual process values ( PV ), see B.3.4 . OperatorAckRequested Boolean O Indicates ... acknowledge is requested by the SafetyConsumer . This flag is received within the RequestSPDU . ActivateFSV ( Fail-safe substitute values) Boolean I By setting this input to "1" the SafetyConsumer
OPC-10000-15 – OPC Unified Architecture - Part 15: Safety

6.3.4.2 SAPI of SafetyConsumer

SafetyProvider . When changing Enable to "1" the SafetyConsumer will restart safe communication. The variable can be used to delay the start of the safety communication according to this ... communication errors were detected in the past, so the SafetyConsumer decided to switch to fail-safe substitute values. 2) Currently, no communication errors occur, and hence operator acknowledgment is possible
OPC-10000-15 – OPC Unified Architecture - Part 15: Safety

6.3.4.3 Motivation for SAPI Operator Acknowledge (OperatorAckConsumer)

faulty message, it checks whether the assumption is still valid, and switches to fail-safe substitute values otherwise. Returning to process values then requires an operator acknowledgment. Operator Acknowledge
OPC-10000-15 – OPC Unified Architecture - Part 15: Safety

6.3.4.5 Motivation for SPI SafetyOperatorAckNecessary

SafetyOperatorAckNecessary This parameter determines whether automatic restart (i.e. automatically switching back from fail-safe values to process values ) is possible for the safety function or not. It is expected
OPC-10000-15 – OPC Unified Architecture - Part 15: Safety

6.4.2 Diagnostics messages of the SafetyConsumer

incorrect ID. 0x01 A Yes SD_IDerrOA The SafetyConsumer has switched to fail-safe substitute values due to an incorrect ID. Operator acknowledgment is required. Mismatch of SafetyBaseID .2 0x11 ... IDerrOA The SafetyConsumer has switched to fail-safe substitute values due to an incorrect ID. Operator acknowledgment is required. Mismatch of SafetyProviderID . 0x12 B, E Yes SD_IDerrOA The SafetyConsumer
OPC-10000-15 – OPC Unified Architecture - Part 15: Safety

7.2.1.5 ResponseSPDU: SafetyData

SafetyData is fixed. SafetyData may contain qualifiers for a fine-grained activation of fail-safe substitute values. For valid process values , the respective qualifiers are set to 1 (good), whereas ... value 0 (bad) is used for invalid values. Invalid process values are replaced by fail-safe substitute values in the SafetyConsumer 's safety application
OPC-10000-15 – OPC Unified Architecture - Part 15: Safety

7.2.2.5 SafetyConsumer state diagram

Endif SAPI.FSV_Activated:= 1 RequestSPDU.Flags.FSV_Activated:= 1 NOTE 1 If a safety application prefers fail-safe values other than binary 0, this can be implemented in the safety application
OPC-10000-15 – OPC Unified Architecture - Part 15: Safety

9.4 PFH and PFD values of a logical safety communication link

happened more than SafetyErrorIntervalLimit time units ago. Otherwise, it will make a transition to fail-safe values, which can only be left by manual operator acknowledgment, see 6.3.4.3 . This directly
OPC-10000-15 – OPC Unified Architecture - Part 15: Safety

B.3.4 Use case 3: bidirectional communication and single, one-sided OA

controller A suffices for re-establishing the bidirectional connection. Both sides will cease delivering fail-safe values and continue sending process values . This is accomplished by connecting OperatorAckProvider with OperatorAckConsumer
OPC-10000-15 – OPC Unified Architecture - Part 15: Safety

B.3.5 Use case 4: bidirectional communication and single, two-sided OA

controller B suffices for re-establishing the bidirectional connection. Both sides will cease delivering fail-safe values and continue sending process values . This is accomplished by the logic circuits shown