General interface health points

The general interface health points pertain to the operation of the interface in general. A list of scan class health points follows. The scan class health points require a valid scan class be configured in Location4 of the PI point. The general interface health points do not consider the Location4 value.

• Heartbeat [UI_HEARTBEAT]

  The heartbeat point is the primary PI point used to determine if the interface is running. If the value of the heartbeat point is updating, then the interface is running but not necessarily connected to and collecting data from a data source. The default update interval is 1 second if there are no scan classes defined for the interface.

  If the interface has defined scan classes, the update interval will be set to the highest frequency (lowest value) scan rate with the following limitations. If the scan rate is less than 1 second, the update interval will be set to 1 second. If the scan rate for the highest frequency scan class is greater than 1 minute, the update interval will be set to 60 seconds. The value written to the heartbeat point increments from a value starting at 1, increments to a value of 15 and then restarts at 1.

  The heartbeat point will stop updating if the interface is shut down or if the interface is in a deadlock situation.

  Note: The interface health heartbeat point is completely separate from the UniInt failover heartbeat point. An interface can have both an Interface health heartbeat point and a UniInt failover heartbeat point loaded simultaneously.

• Device status [UI_DEVSTAT]

  The device status point stores communication information about the interface and the data source. The device status point is a string type PI point evaluated only while the heartbeat point is updating. During normal shutdown of the interface, the string text of 4 | Intf Shut will be written to this point.

  Format: n | UniInt-provided string text | interface-specific text (when provided).

  The n value in the text and the pipe separator are formatting devices that may be used to quickly parse and analyze the value of the device status point.

The update values and meaning of this point are as follows:

• System Digital State “Good"

  The interface is properly communicating with the data source and is able to read/write data to the device as required. When in this state, the system digital state of Good will be written to the device status point.

• 1 | Starting

  The interface is starting.

• 2 | Connected / No Data

  The interface is connected to the data source. While in this state, the interface is not capable or reading or writing data to the data source. Optional text that can be provided by the interface is appended to the UniInt-provided string value.

• 3 | n device(s) in error

  The interface is unable to communicate with n device(s). Optional text that may be provided by the interface is appended to the UniInt-provided string value.

• 4 | Intf Shutdown

  The interface is shutting down.

• 5 | interface_specific_message

  Text provided by the interface will be the only text following the 5 |.

• Scan class information [UI_SCINFO]

  The scan class information point is a string point that contains the number of scan classes used by the interface and their associated scan rates. The heartbeat scan rate is also included in the string. The point is updated once at interface startup and at each performance interval.

  For example, the value for the scan class information point for an interface with three scan classes of 5 seconds, 10 seconds and 60 seconds is 3 | 5 | 5 | 10 | 60, where the first number is the number of scan classes and the second is the heartbeat update rate. Numbers that follow depend on the rate and number of scan classes defined, with each rate written in seconds.

• IO rate (events per second) [UI_IORATE]

  Counts the number of all values (inputs, outputs, triggered inputs) being sent to PI Server before exception processing occurs. This point will update based on the update rate of the heartbeat point and may report zero for update intervals where no data was sent to PI Server. If the value stops updating in PI Server, then this is an indication that the interface has stopped collecting data.

• Message counter [UI_MSGCOUNT]

  Tracks the number of messages the interface has logged to the pipc.log file since interface start-up. The value of this point is used solely for ad-hoc queries and diagnostics. Generally, a large number of messages indicate a problem that should be investigated.

• Output rate [UI_OUTPUTRATE]

  Counts the number of output point events sent to PI Server before exception processing. Output points update based on an event and cannot be scheduled for an update rate. Therefore, the values of output points are updated at the same rate as the heartbeat point and reset after the performance summary interval.

  Note: If no output points are defined, the digital state value of No Data will be written to the point.

• Output bad value rate [UI_OUTPUTBVRATE]

  Counts output point events sent to PI Server (before exception processing) with status other than good. Output points update based on an event and cannot be scheduled for an update rate. The value is updated at the same rate as the heartbeat point and is reset after the performance summary interval.

  Note: If no output points are defined, the digital state value of No Data will be written to the point.

• Interface point count [UI_POINTCOUNT]

  Counts the number of PI points loaded by the interface. This count includes all input, output, and triggered input points. This count does not include any interface health points or performance points.

• Trigger input rate [UI_TRIGGERRATE]

  Counts number of triggered input point events that are sent to PI Server before exception processing. Triggered input points update based on some event and cannot be scheduled for an update rate. Therefore, the value of these points will be updated at the same rate as the heartbeat point and will reset after the performance summary interval.

  Note: If no trigger input points are defined, the digital state value of No Data will be written to the point.

• Trigger input bad value rate [UI_TRIGGERBVRATE]

  Counts triggered input point events sent to PI Server (before exception processing) with status anything other than good. Triggered input points update based on an event and cannot be scheduled for an update rate. The value is updated at the same rate as the heartbeat point, and is reset after the performance summary interval.

  Note: If no trigger input points are defined, the digital state value of No Data will be written to the point.