Protective Instrument Loop Sensor System Records

Protective Instrument Loop Sensor System records store details about a protective instrument loop sensor system that you have created as part of SIL verification. This topic provides an alphabetical list and description of the fields that exist for the Protective Instrument Loop Sensor System family and appear on the Protective Instrument Loop datasheet by default. The information in this table reflects the baseline state and behavior of these fields.

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Field	Data Type	Description	Behavior and Usage
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 sensor system 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 sensor system.
Calculated PFH	Number	A number representing the probability that the sensor system 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 sensor system.
Calculated STR	Number	A number representing the spurious trip rate for the sensor system.	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 sensor system 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 sensor system.	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.
HFT	Number	A number representing the hardware fault tolerance, or the number of failures the sensor system can tolerate before failing.	For example, a sensor system with 1oo2 redundancy has a HFT of 1 because it can tolerate one failure and can still continue to operate.
MTTFS	Number	A number representing Mean Time To Fail Spuriously for a Sensor System.	This field is disabled. The GE Digital APM system calculates and populates this value.
Number of Groups	Number	The number of sensor groups in the system.	This field is disabled and populated with the number of sensor groups in the system.
SIL Architectural Constraints	Number	A number that represents the SIL value for the sensor system, 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 sensor system, which is based on the systematic capability that is defined in the Test Architecture Constraints field.	This field is disabled. The GE Digital APM system calculates and populates this value.
System ID	Character	The ID of the sensor system.	This value is required and is populated with a default value. You can, however, provide a different value. This value must be unique.
Voting Between Groups	Character	The voting architecture that represents the minimum number of sensor groups that should trip (in the event of a failure) and the number of sensor groups that are available in the system. For example, if the voting is 1oo2, then for the logic solver to detect a failure, at least one sensor group should trip out of the two sensor groups that are available in the group.	This field is updated automatically when you add or remove a sensor group from the system. The following combinations are available: 1oo1 1oo2 2oo2 1oo3 2oo3 3oo3 1oo4 4oo4 This value is required.