Modify the [DQTAG] section based on project requirements

The [DQTAG] section indicates which flags fields in AVEVA Enterprise SCADA should be inspected. This is intended for PI data quality tags only.

A data quality tag is used to represent the data quality of a PI tag. Appropriate digital states should be configured in PI prior to the creation of a tag. The digital states that should be configured in the data quality digital set are determined by the configuration of the [DQTAG] section in the pioas_cfg.dat file.

The following table shows a schema for a data quality tag. It is based on a set of virtual bit states, with each bit representing a field within the flags structure. The bit positions have little relationship to the order of the states; they represent only the relevant data quality combinations that could occur with the tag.

For example, the fresh, error and offscan fields may be important for this particular tag. The tag has been configured so that if the fresh field is set, then the point stores fresh data; if the error field is set, then the point is in the error state; if the offscan field is set, the data is in the off scan state. Because there are three bit positions, the data quality in PI could have eight possible states. Not all of these states may occur, but eight consecutive locations must still be configured. The possibilities are shown in the table below.

While the above table shows all the possible combinations, the actual digital states used, based upon what makes sense for the point, could be different. One possibility is shown in the table below.

The section [DQTAG] should be configured appropriately in the pioas_cfg.dat. Using the example above, the corresponding [DQTAG] section should look like the following:

[DQTAG]

1=fresh 0

2=error 1

3=offscan 1

Follow the procedure below to create the data quality set in PI to match the configuration in the [DQTAG] section.

To create a data quality digital set in the PI server

1. On a PI server, start PI System Management Tools.

2. In the System Management Plug-Ins panel, select Points > Digital States

   PI System Management Tools displays a list of digital sets defined for the PI Server.

   

3. Do one of the following:

   • Right-click in the Digital States window, and select Add Set.

   • Select the Add icon.

   PI System Management Tools adds a new Digital State.

4. Enter the desired name of the new DQSet.

5. Add the State Names and State Numbers.

   Configure the DQSet as follows to match the values defined in the [DQTAG] section of the configuration file:

   State Number	State Name
   0	Good
   1	Stale
   2	Error
   3	StaleError
   4	Offscan
   5	StaleOffscan
   6	ErrorOffscan
   7	StaleErrorOffscan