Protective Instrument Loop Logic Solver Records

Protective Instrument Loop Logic Solver records store details about logic solvers for a protective instrument loop. This topic provides an alphabetical list and description of the fields that exist for the Protective Instrument Loop Logic Solver family and appear on the Protective Instrument Loop Logic Solver datasheet. The information in this table reflects the baseline state and behavior of these fields. This list is not comprehensive.

This family is enabled for site filtering, which means that records in this family can be assigned to a specific site, and will then only be accessible to users who are assigned to the same site and have the appropriate license and family privileges. See the Site Filtering section of the documentation for more information on using this feature.

Field	Data Type	Description	Behavior and Usage
App Diagnostic Test	Logical	Indicates whether application diagnostic testing is considered for the logic solver.	None
Approved Custom Device	Logical	Indicates whether the logic solver that is identified in the Exida Name field is approved for use in the protective instrument loop.	This field is disabled and selected if the logic solver has been approved to use via the Validation Failure Rate Reference Data feature.
Architectural Type	Character	Indicates whether the device is a simplex or a complex device.	If the Manual Entry check box is cleared, this value is disabled and populated with one of the following values based on the device identified in the Exida Name field: A (simplex device) B (complex device) If the Manual Entry check box is selected, this field is enabled.
Automatic Channel Count	Logical	Indicates whether the number of each type of channel is counted.	If you select this check box, the Channels column in the Channels/Modules pane is populated with the number of channels.
Automatic Prooftest Switchover	Logical	Indicates whether the logic solver performs proof tests automatically.	If you select this check box, the logic solver performs proof tests automatically.
Automatic Prooftest Switchover Interval	Number	A numeric value representing the frequency at which proof tests are performed by the logic solver.	This value is measured in months.
Availability	Number	A number representing the percentage of time between proof tests that the logic solver is expected to be available.	The GE Digital APM system calculates this value using the following calculation: *Availability = (1 - PFD) 100**
Calculated PFD Avg	Number	A number representing the probability that the logic solver will fail to react during a demand when the loop is operating in a low demand mode.	This field is disabled. The GE Digital APM system calculates and populates this value. This value depends on the failure rate of the logic solver.
Calculated PFH	Number	A number representing the probability that the logic solver will fail to react during a demand when the loop is operating in high demand or continuous mode of operation.	This field is disabled. The GE Digital APM system calculates and populates this value. This value depends on the failure rate of the logic solver.
Calculated STR	Number	A number representing the spurious trip rate for the logic solver.	This field is disabled. The GE Digital APM system calculates and populates this value.
Common Cause (Beta)	Number	A number representing the percentage of failure that would affect the functioning of multiple devices. For example, a power supply failure for a logic solver that is shared across multiple loops can cause all the loops to fail. In this case, the beta factor is the probability that the loops fail in case of a power supply failure to the logic solver.	If the value in the Voting field is 1oo1 or 1001D, this value is not applicable. This value is populated automatically when you select a device.
Description	Character	A brief description of the logic solver.	None
Device Name	Character	The name of the logic solver device.	This field is disabled and populated when you link or apply a logic solver from Exida's Safety Equipment Reliability Handbook (SERH).
Diagnostic Test Automatic/Manual	Character	Indicates whether the application diagnostic test is automatic or manual.	You can select one of the following values: Automatic Manual
Diagnostic Test Coverage	Number	The percentage of failures that could be detected as part of automatic diagnostic test coverage.	None
Diagnostic Test Interval	Number	The application diagnostic test interval for the logic solver.	None
Diagnostic Test Interval UOM	Character	The units for the application diagnostic test interval that you have specified in the Diagnostic Test Interval field.	You can select one of the following values: Months Days
Equipment	Character	The ID of the Equipment to which the Protective Instrument Loop Logic Solver is linked.	This field contains a button, which you can select to search for the desired Equipment. You can link only one Equipment. This field is disabled and populated when you link or apply a logic solver from Exida's Safety Equipment Reliability Handbook (SERH) or from the approved custom devices in the GE Digital APM system.
Functional Location	Character	The ID of the Functional Location that is linked to the Protective Instrument Loop Logic Solver record.	This field contains a button, which you can select to search for the desired Functional Location. You can link to only one Functional Location. This field is disabled and populated when you link or apply a logic solver from Exida's Safety Equipment Reliability Handbook (SERH) or from approved custom devices in the GE Digital APM system.
HFT	Number	A number representing the hardware fault tolerance, or the number of failures the logic solver can tolerate before failing.	For example, a logic solver with 1oo2 redundancy has a HFT of 1 because it can tolerate one failure and can still continue to operate.
Logic Solver ID	Character	An ID for the logic solver.	This value is required and is populated with a default value. You can, however, provide a different value. This value must be unique.
Manual Entry	Logical	Indicates whether you will enter data in a Protective Instrument Loop Logic Solver Channel manually or the GE Digital APM system will populate this values.	If this check box is selected, the button in the Channels/Modules section appears. Once you select this check box, you cannot clear it.
MTTFS	Number	A number representing Mean Time To Fail Spuriously for a logic solver. For example, suppose a logic solver senses a hazard that does not exist. In this case, MTTFS is the expected time that the process fails spuriously.	The GE Digital APM system calculates this number automatically and displays it as read-only. This value is measured in years.
MTTR	Number	A number representing Mean Time To Repair, or the time it takes to repair the logic solver after a failure is detected.	This value is measured in hours. The value that you enter must be between 4 and 336. Otherwise, an error message will appear. This value is required.
Proof Test Coverage	Number	A number representing the percentage of failures that are detected by the proof test (i.e., how effectively the proof test identifies failures). For example, 100% proof test coverage indicates that the proof test would identify 100% of the failures that could have occurred.	The number that you enter must be between 0 and 100. Otherwise, an error message will appear. This value is required.
Proof Test Interval	Number	A number representing the monthly intervals at which the proof test should be performed.	The number that you enter must be between 1 and 360, or an error message will appear. This value is required.
Reference Data Date	Date	The date on which that the reference data was published for the device that is identified in the Exida Name field.	This field displays the Calendar feature. When the Manual Entry check box is selected, this field is enabled. When the Manual Entry check box is cleared, this value is disabled and populated with the date on which the reference data was published for the device that is identified in the Exida Name field.
Reference Data Reference	Character	The specific failure data reference as it appears in the Exida data source that is identified in the Reference Data Source field.	When the Manual Entry check box is selected, this value is enabled. When the Manual Entry check box is cleared, this field is disabled and populated with the data reference for the device that is identified in the Exida Name field.
Reference Data Revision	Character	A number that represents the number of times the reference data has been revised in the Exida database.	When the Manual Entry check box is selected, this value is enabled. When the Manual Entry check box is cleared, this field is disabled and populated with the data revision for the device identified in the Exida Name field.
Reference Data Source	Character	The source of the reference data (e.g., Exida).	When the Manual Entry check box is selected, this value is enabled. When the Manual Entry check box is cleared, this field is disabled and populated with the data source for the device identified in the Exida Name field.
SIL Architectural Constraints	Number	A number that represents the SIL value for the logic solver, which is based on the architectural constraints that are defined in the Test Architecture Constraints field.	This field is disabled. The GE Digital APM system calculates and populates this value.
SIL Systematic Capability	Number	A number that represents the SIL value for the logic solver which is based on the systematic capabilities that are defined in the failure rate data.	This field is enabled or disabled based on the following criteria: When the Manual Entry check box is selected, the SIL Sytematic Capabilities field is enabled. When the Manual Entry check box is cleared, the GE Digital APM system calculates the number automatically, based on the systematic capabilities that are defined in the failure rate data associated with the logic solver device, and displays one of the following values as read-only in the SIL Systematic Capability field: 0 (zero) 1 2 3 4
Voting	Character	The configuration of the logic solver that help achieve the target SIL value.	This list contains the following options: 1oo1 1oo1D 1oo2 1oo2D 1oo3 2oo3 3oo3 This value is populated automatically when you select a device.