Specifications

20 – Using PlantScape Data in Other Applications
406 R400
For example, Parameter001 = ‘TankLevel.pv’. This sets Value001 to be the value
of the TankLevel’s PV, and Quality001 to be the quality of the corresponding
history value. The quality indicates the state of the point at the time the sample
was taken. Possible qualities are:
GOOD
There are no errors.
BAD
The point was not scanning at time sample taken.
NOT HISTORIZED
The specified parameter has not been assigned to history, but the point has
been implemented.
POINT UNSPECIFIED
One of the parameters in the query does not have the corresponding point
specified.
UNIMPLEMENTED
The point specified does not exist in the database.
If the parameter name is not specified, it defaults to the point’s PV.
As an example, a query set up in Microsoft Access is shown below. This query
returns snapshot history values of the PV parameter of the point TankLevel for
every minute between 10 am and 4 pm on the 25/7/97.
Figure 20.9 Design View of a History Table Query in Access
plscpcg.book Page 406 Monday, May 28, 2001 10:11 AM