The following table shows a summary of the basic functionality of j5 Wonderware Historian interface.
|
Function |
Read |
Read Multiple |
Write |
|---|---|---|---|
|
Current Value |
Yes |
Yes |
No |
|
Historical Value |
Yes |
Yes |
Yes |
|
Historical Data Changes |
Yes |
Yes |
No |
|
Aggregate Values |
Yes |
No |
No |
In addition to the above, functionality for displaying tag values in Charts and Sparklines in j5 IndustraForms is available.
The following aggregates are supported by the interface:
-
Sum
-
Average
-
Maximum
-
Minimum
For some aggregates, there are several ways in which aggregate queries can be implemented in the Wonderware Historian:
-
Use the built in SQL Server functions on the Runtime.dbo.History table (for example, MIN, MAX, AVG) this applies to discreet and continuous tags as the History table contains mixed TagTypes.
As the value is calculated, the quality cannot be determined for the tag and is therefore
assumed to be Valid.
-
Use the Wonderware Historian built-in retrieval modes. Various retrieval modes allow data stored in Wonderware Historian in different ways.
-
Query the *AnalogSummaryHistory* table which uses the average retrieval mode to do calculations and contains "Min", "Max", "Avg" columns that can be queried. This only applies to continuous tags. If Discrete tags were to be supported, can use StateSummaryHistory table but then would need to know which state was being queried.
The table below outlines the various query methods available for different aggregates.
|
Aggregate |
1. SQL Query Function |
2. Historian Retrieval Modes |
3. AnalogSummaryHistory |
|---|---|---|---|
|
Sum |
SUM (with Full Retrieval) |
N/A |
N/A |
|
Average |
AVG (with Full Retrieval) |
Avg Retrieval Mode |
Yes |
|
Maximum |
MAX |
N/A |
Yes |
|
Minimum |
MIN |
N/A |
Yes |