Opc interface to the pi system

Interface Diagnostics Configuration

The Interface Point Configuration chapter provides information on building PI points for collecting data from the device. This chapter describes the configuration of points related to interface diagnostics.

The procedure for configuring interface diagnostics is not specific to this Interface. Thus, for simplicity, the instructions and screenshots that follow refer to an interface named Generic. In actuality, OSIsoft does not offer an interface called Generic.

Some of the points that follow refer to a "performance summary interval". This interval is 8 hours by default. You can change this parameter via the Scan performance summary box in the UniInt – Debug parameter category pane:

Scan Class Performance Points

Those familiar with other PI interfaces may have used Performance Points before. These tags document how long it takes to complete a scan. Due to the architecture of this interface, performance points are not valid -- the server’s response is asynchronous, so the time to “scan” bears no relation to the amount of time it may take to get the data from the server.

Performance Counters Points

When running as a Service, this Interface exposes performance data via Windows Performance Counters. Such data include:

• 
  the amount of time that the Interface has been running;
  
• 
  the number of points the Interface has added to its point list; and
  
• 
  the rate at which the Interface is collecting data.
  

OSIsoft's PI Performance Monitor Interface is capable of reading these performance values and writing them to PI points. Please see the Performance Monitor Interface to the PI System for more information.

If there is no PI Performance Monitor Interface is installed as a Service on the same computer running this Interface, you cannot use the ICU to create this Interface's Performance Counters Points:

After installing the PI Performance Monitor Interface as a service, select this Interface from the Interface drop-down list, click Performance Counters in the parameter categories pane, and right click on a row containing a Performance Counters Point to bring up the context menu:

Click Create to create the Performance Counters Point for that particular row. Click Create All to create all the Performance Counters Points.

To see the current values (snapshots) of the Performance Counters Points, right click and select Refresh Snapshots.

The PI Performance Monitor Interface – and not this Interface – is responsible for updating the values for the Performance Counters Points. So, make sure that the PI Performance Monitor Interface is running correctly.

up_time

The up_time Performance Counters Point indicates the amount of time (in seconds) that this Interface has been running.

io_rates

The io_rates Performance Counters Point indicates the rate (in event per second) at which this Interface writes data to its input tags.

log_file_msg_count

The log_file_msg_count Performance Counters Point indicates the number of messages that the Interface has written to pipc.log.

pts_edited_in_interface

The pts_edited_in_interface Performance Counters Point indicates the number of point edits the Interface has detected. The Interface detects edits only for those points whose PointSource attribute matches its Point Source parameter and whose Location1 attribute matches its Interface ID parameter.

pts_added_to_interface

The pts_added_to_interface Performance Counters Point indicates the number of point added the Interface has added to its point list.

pts_removed_from_interface

The pts_removed_from_interface Performance Counters Point indicates the number of point added the Interface has removed from its point list.

point_count

A point_count Performance Counters Point is available for each Scan Class of this Interface. The ICU uses a naming convention such that the tag containing "(Scan Class 1)" (for example, sy.perf.etamp390.E1(Scan Class 1).point_count refers to Scan Class 1, "(Scan Class 2)" refers to Scan Class 2, and so on. The tag containing "_Total" refers to the sum of all Scan Classes.

This point indicates the number of tags per Scan Classes.

scan_time

A scan_time Performance Counters Point is available for each Scan Class of this Interface. The ICU uses a naming convention such that the tag containing "(Scan Class 1)" (for example, sy.perf.etamp390.E1(Scan Class 1).scan_time refers to Scan Class 1, "(Scan Class 2)" refers to Scan Class 2, and so on.

The scan_time Performance Counters Point indicates the number of milliseconds the Interface takes to read data from the device and fill in the values for the tags. This point is similar to the [UI_SCINCANTIME] Health Point.

sched_scans_%missed

A sched_scans_%missed Performance Counters Point is available for each Scan Class of this Interface. The ICU uses a naming convention such that the tag containing "(Scan Class 1)" (for example, sy.perf.etamp390.E1(Scan Class 1).sched_scans_%missed refers to Scan Class 1, "(Scan Class 2)" refers to Scan Class 2, and so on. The tag containing "_Total" refers to the sum of all Scan Classes.

The sched_scans_%missed Performance Counters Point indicates the percentage of scans the Interface missed since startup. A missed scan occurs if the Interface performs the scan one second later than scheduled.

sched_scans_%skipped

A sched_scans_%skipped Performance Counters Point is available for each Scan Class of this Interface. The ICU uses a naming convention such that the tag containing "(Scan Class 1)" (for example, sy.perf.etamp390.E1(Scan Class 1).sched_scans_%skipped refers to Scan Class 1, "(Scan Class 2)" refers to Scan Class 2, and so on. The tag containing "_Total" refers to the sum of all Scan Classes.

The sched_scans_%skipped Performance Counters Point indicates the percentage of scans the Interface skipped since startup. A skipped scan is a scan that occurs at least one scan period after its scheduled time.

sched_scans_this_interval

A sched_scans_this_interval Performance Counters Point is available for each Scan Class of this Interface. The ICU uses a naming convention such that the tag containing "(Scan Class 1)" (for example, sy.perf.etamp390.E1(Scan Class 1).sched_scans_this_interval refers to Scan Class 1, "(Scan Class 2)" refers to Scan Class 2, and so on. The tag containing "_Total" refers to the sum of all Scan Classes.

The sched_scans_this_interval Performance Counters Point indicates the number of scans that the Interface performed per performance summary interval.