Performance counter point types

Device Actual Connections

The actual number of data sources currently connected to the interface instance and working properly. Only applies to the instance (_Total).

Device Expected Connections

Total number of devices that the interface is expected to be communicating with at runtime. Only applies to the instance (_Total)

Device Scan Time (milliseconds)

Time in milliseconds to call developer function and gather data from a data source. Does not include the amount of time to write the values to PI Server. There is one Device Scan Time counter per scan class. Applies to scan classes only. Does not apply to the instance (_Total).

Device Status

Stores communication information about the interface and the connection to the data source. The device status performance counter indicates status using the following values:

• 0

  Interface working properly, reading/writing data

• 10

  Connected to device, not receiving data

• 30 to 79

  Interface-specific statuses

• 50

  UniInt failover is in a state where the backup interface may take over if needed after a certain period of time. 10 minutes is the default, but can be configured using the Active ID tag's location5 attribute.

• 80

  Percentage of devices connected below minimum required

• 90

  Starting interface, not connected to device

• 95

  Communication error with device

• 99

  Shutting down the interface

• 100

  For internal use only

  Only applies to the instance (_Total).

Failover Status

Stores the failover state of the interface when configured for UniInt level failover. Contains 0 if the interface is primary, 1 if backup. Only applies to the instance (_Total).

Interface up-time (seconds)

The number of seconds since the interface has started. This counter is incremented once a second. Only applies to the instance (_Total)

IO Rate

Note: This counter was removed from UniInt starting with version 4.5.0.x. The counter has been reinstated for UniInt 4.6.0.x and later.

The number of events per second received by the interface. If this counter is viewed from the Windows performance monitor, increase the update time of the performance monitor to the minimum scan period for the interface. For example, if the minimum scanning period for the interface is 5 seconds (/f=5), set the update rate of the performance monitor to 5 seconds by selecting the Chart command from the Options menu. On the window, change the periodic update time to 5 seconds. If the update time is left at 1 second, the IO Rate appears to go to zero between scans because no events are received between scans.

Only applies to instance (_Total).

Log file message count

Number of messages that have been written to the log file. Only applies to the instance (_Total).

PI Status

Status of the connection to the PI Server. If the connection is GOOD the value is 0. If the connection is anything other than GOOD the value is 1. Only applies to the instance (_Total)

Point Count

Number of points loaded by the interface. Does not include UniInt-controlled points such as health points or failover points. Applies to both instance (_Total) and scan classes.

Points added to the interface

Number of points that have been added to the interface. Only applies to the instance (_Total).

Point edited in the interface

Number of point edits that have occurred. Only applies to the instance (_Total).

Points Good

Number of points that have sent a GOOD current value to PI Server. If the last value sent to PI Server is a System Digital State value or the last value sent to PI Server is older than the Stale timeout, the point is not counted in the Points Good count. The value of Points Good equals the value of Point Count when all points are updating with a GOOD current value. Only applies to instance (_Total).

Points In Error

Number of points that have sent a system digital state value as the current value to PI Server. The total of Points In Error, Points Good, and Points Stale equals Point Count. Only applies to the instance (_Total).

Points removed from the interface

Number of points that have been removed from the interface. Only applies to the instance (_Total).

Points Stale 10(min)

Points Stale 30(min)

Points Stale 60(min)

Points Stale 240(min)

Number of points that have not received a new value in the last 10, 30, 60 or 240 minutes. If a point had a GOOD current value that is now stale, the Points Stale count goes up and the Points Good count goes down. Only good points go stale; points in error do not. Only applies to the instance (_Total).

Scan Time (milliseconds)

Time in milliseconds to call developer function and to write values to PI Server. One "Scan Time" counter per scan class. Does not apply to the instance. Applies to scan classes only.

Scheduled Scans: % Missed

Percentage of missed scans since starting the interface. If a scan occurs more than one second after its scheduled time, the scan is considered missed. One "Missed Scans" counter per scan class. Applies to both instance (_Total) and scan classes.

Scheduled Scans, % Skipped

Percentage of skipped scans since starting the interface. If a scan occurs one scan period or more after its scheduled time, those scans are considered skipped. One "Skipped Scans" counter per scan class. Applies to both instance (_Total) and scan classes.

Scheduled Scans: Scan count this interval

The total number of scans in the current performance interval. This total is the current sample size that is used to evaluate the % missed scans and the % skipped scans. The performance interval is 8 hours by default, and can be changed using PI ICU (Debug tab) or by setting the /perf command-line parameter. The minimum performance interval is 60 seconds. When the performance interval is exceeded, the previous samples are discarded and sampling starts again. Applies to both instance (_Total) and scan classes.

Standard deviation above mean

The standard deviation of values above the currently calculated mean. Only applies to instance (_Total).

Standard deviation below mean

The standard deviation of values below the currently calculated mean. Only applies to instance (_Total).