Table 35 defines the structure of an MDISInstrumentArbitrationObjectType. Any vendor specified properties that have been implemented within a project should be documented within a similar format and supplied to the DCS vendor. The addition of vendor specific properties will result in a subtype of the MDISInstrumentArbitrationObjectType.
Table 35 – MDISInstrumentArbitrationObjectType Definition
|
Attribute |
Value |
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|
BrowseName |
MDISInstrumentArbitrationObjectType |
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IsAbstract |
False |
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|
References |
Node Class |
BrowseName |
DataType |
TypeDefinition |
Other |
|
Subtype of the MDISInstrumentObjectType |
|
||||
|
0:HasComponent |
Variable |
SourceA |
0:Float |
0:BaseDataVariableType |
M, RO |
|
0:HasComponent |
Variable |
SourceB |
0:Float |
0:BaseDataVariableType |
M, RO |
|
0:HasComponent |
Variable |
ArbitrationMode |
ArbitrationModeEnum |
0:BaseDataVariableType |
M, RO |
|
0:HasProperty |
Variable |
DiscrepancySetPoint |
0:Float |
0:PropertyType |
O, RW |
|
0:HasComponent |
Method |
SetArbitrationMode |
Defined in 6.3.7 |
O |
|
|
ConformanceUnits |
|||||
|
MDIS Instrument Arbitration Base |
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The MDISInstrumentArbitrationObjectType provides for the selection between two analog sources, SourceA and SourceB. The result of the arbitration is shown in the ProcessVariable. The result can be either an average, a selection of one source as default or forcing of one source. See the ArbitrationModeEnum for a complete list of possible modes.
SourceA – a Variable in engineering units that represents the value of the first source of a MDISInstrumentArbitrationObjectType. The EngineeringUnits and Range of the ProcessVariable apply to this value.
SourceB – a Variable in engineering units that represents the value of the first source of a MDISInstrumentArbitrationObjectType. The EngineeringUnits and Range of the ProcessVariable apply to this value.
ArbitrationMode – this enumeration identifies the current arbitration mode. For the complete list of arbitration modes, see section 8.1.10. [note: the selected mode might be different than the current mode reflected in this parameter, for example in the case of a failure the current mode might indicate SourceA even if Average was selected, due to a SourceB failure]
DiscrepancySetPoint – the value represents the maximum allow difference between the SourceA and SourceB values expressed as a percentage based on the full range of the instrument. This value can only be between 0 and 100. For example, if SourceA was 10.0 and SourceB was 20.0 and the instrument range was 0 to 200, the percentage would be 5%.
The MDISInstrumentArbitrationObjectType is a subtype of MDISInstrumentObjectType and inherits the FaultCode Variable. The MDISInstrumentArbitrationObjectType defines the standard FaultCodes (for bits 0-15 as defined in 6.2.2) in Table 36 (currently empty, no additional fault codes defined). All subtypes of this the MDISInstrumentArbitrationObjectType will inherit all FaultCodes defined in this table. Subtypes may define additional FaultCodes in their own table.
Table 36 – MDISInstrumentArbitrationObjectType FaultCode Values
|
Value |
Bit no. |
Description |
|
|
|
|
The MDISInstrumentArbitrationObjectType defines the standard WarningCodes (for bits 0-15 as defined in 6.2.2) in Table 37 (currently empty, no additional warning codes defined). All subtypes of this the MDISInstrumentArbitrationObjectType will inherits all WarningCodes defined in this table. Subtypes may define additional WarningCodes in their own table.
Table 37 – MDISInstrumentArbitrationObjectType WarningCode Values
|
Value |
Bit no. |
Description |
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|
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