UniInt End User
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PI BASemAPI
- Navigate this page:
- /perf
| PERFORMANCE_POINT
or to: PERFORMANCE_POINT=interface_id where interface_id corresponds to the identifier that is specified with the /id parameter on the startup command-line of the interface. The character string PERFORMANCE_POINT is case insenstive. The interface_id does not need to be specified if there is only one copy of an interface that is associated with a particular point source. Set Location4 to correspond to the scan class whose performance is to be monitored. For example, to monitor scan class 2, set Location4 to 2. See the /f parameter for a description of scan classes. Set the PointSource attribute to correspond to the /ps parameter on the startup command-line of the interface. Set the PointType attribute to any of the floating-point point types that are supported by the PI Server. Performance SummariesUniInt monitors interface performance by keeping track of the number of scans that are hit, missed, and/or skipped for scan-based input points. Scans that occur on time are considered hit. If a scan occurs more than 1 second after its scheduled time, the scan is considered missed. If a scan occurs 1 scan period or more after its scheduled time, then 1 or more scans are considered skipped. Say that a particular scan class has a period of 2 seconds. If a scan for this class occurs 1.1 seconds after its scheduled time, then 1 scan has been missed. However, no scans have been skipped because the next scan still has the opportunity to occur at its scheduled time, which happens to be 0.9 seconds after the last scan in this case. For scans that have periods of 1 second or less, the above definition of a missed scan does not make sense. In these cases, scans are considered either hit or skipped. Since every skipped scan is also considered to be a missed scan, the scan performance summary should indicate the same percentage of skipped and missed scans for scan classes with periods of 1 second or less. By default, UniInt prints out a performance summary to the message log every 8 hours if the hit ratio (hit ratio = hits / (hits + misses)) drops below 0.95. The performance summary shows the percentage of scans that are missed and skipped for every scan class. The frequency at which performance summaries are printed out can be adjusted using the /perf command-line parameter. For interfaces that use unsolicited input points, performance summaries should be inactivated by setting /perf=0 because performance summaries are meaningless for unsolicited inputs. Download 1.93 Mb. Share with your friends:
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