PI Processbook X-Y Plot Tools Pairing Option

Pls be very careful when plotting X-Y points in PI Processbook. This is such a powerful tool !!

Below is taken from help file.

Configure Pairings
Once the tags are listed in the Tags in Plot list, configure the method for pairing values between X and Y in the Data Retrieval Methods box.

X Tag—choose either Recorded or Interpolated for the retrieval method.
Interpolated—an interval may be entered in the Plot Time section. Interpolated is the default for tags and is disabled for ODBC and Custom data sets. This method retrieves interpolated values for the specified time range in regular intervals. For example, if the time range is *-1h to * and the Interval is 10m, then six values spaced 10 minutes apart are returned. This option provides a way to get evenly sampled data.
Recorded—Retrieves archive values between the specified start and end time.
Y Tag(s)—the Y tag data retrieval method applies to individually selected tags in the Tags in Plot list (unless the Use for all Y tags check box is selected). The default data retrieval method for Y tags is Synchronize.
Y Tags, paired by position in the list—To use multiple time ranges, select Recorded or Interpolated. In this case, data is paired by position in the point list. If Interpolated is selected for the X tag as well, the interval value for the Y tag defaults to the one for the X tag.
When Recorded is the retrieval mechanism, the results are not skewed by minor timestamp differences.

Y Tags, paired by timestamps—to pair values by time, rather than by list position, choose one of these retrieval methods: Synchronize, Match, Match or Previous, or Match or Next.
Synchronize—synchronizes data found for X with data for Y using the timestamps for the X data. This may result in interpolated data values for Y.
Match—find the event for Y corresponding to the exact timestamp as X. If no matching event is found, no match is made for that X value.
Match or Previous—find the event for Y corresponding to the exact timestamp as X. If there is none, find the event that is the closest but earlier in time.
Match or Next—find the event for Y corresponding to the exact timestamp as X. If there is none, find the event that is the closest, but later in time.
Synchronize and Match—use different PI SDK value retrieval methods. Synchronize uses TimedValues. Match uses RecordedValues and then uses the values where the timestamps match.

Note: Synchronize is disabled for ODBC and Custom data sets.

If you select Synchronize or any of the Match options, the start and end times for that tag are set the same as for the X tag and cannot be changed.

Note: The XYPlot supports ODBC data sets that don't contain timestamps. This type of entry must be plotted as a Y-tag, and data values must be retrieved using the Recorded retrieval method. If a tag is changed from a Y tag to an X tag and has a value for Retrieval Method that is only valid for Y tags, the method is changed to Interpolated. If the tag is a data set, the method is changed to Recorded.

In all cases, if a pair is not made, the unmatched X or Y events are ignored.

Use for all Y tags—Selecting this box indicates that the Y-tags data retrieval mechanism applies for all Y-tags. If one of the tags is a Custom or ODBC data set and the selection mechanism is Interpolated or Synchronize, the selection mechanism will be Recorded or Match respectively for that tag only.