PI point configuration

PI Interface for Ramp Soak Simulator Data is installed and configured with Data Archive, is an excellent source of test data. You can configure points to generate various types of randomized data. The default point source for this interface is "9". To list the points created using the steps in the Create default PI points section and to create points for the interface, use PI System Management Tool's Point Builder option or the Point Builder Excel add-in.

• Location1: Time in minutes to wait before cycle start at simulator startup.

• Location2: Time in minutes between cycles.

• Location3: Maximum signal noise specified as percentage * 10. For example, for 10 percent noise, enter 100.

• Location4 (Scan Class): Determines the frequency at which new values are generated.

• Location5: Phase end time noise specified as percentage * 10. For example, for 10 percent, enter 100.

• InstrumentTag: Configures the optional batch active tag and phase tags. Specify the tag names separated by a space. At the start of a cycle (the beginning of the first phase), the interface writes a value of 1 to the batch active tag and 0 to the phase tag. The phase tag is incremented by 1 at the start of each subsequent phase. At the end of the last phase, the interface writes a value of 0 to the batch active tag. This feature allows simulated batches to be tracked using PI-Batch.

Note: Do not configure more than one such tag for a simulated unit. If you are simulating batches, you might have more than one Ramp Soak point for the simulated unit (for example, temperature and pressure). Only one of those points can specify active and/or phase tags, otherwise both will write to the active and phase tags, most likely at different times.

ExDesc: Phase information that is required to simulate ramp-ups, ramp-downs and soaks. Each phase requires an entry formatted as (period, end_value), where:

• period is the time in minutes.

• end_value is the value for the tag at the end of the phase period. By default, the values are reported in engineering units. To report values as a percentage of range, specify a percent sign (%) after the end value parameter.

For example, to configure a cycle with five phases, specify:

(10,33) (11,33) (15,50) (15,43) (3,0)

This configures five phases for a total cycle time of 54 minutes:

• Phase 1: 10-minute ramp from the tag's zero to 33

• Phase 2: 11 minute period remain at 33

• Phase 3: 15-minute ramp from 33 to 50

• Phase 4: 15-minute ramp down to 43

• Phase 5: 3-minute ramp down to 0

The resulting trend for the tag looks like this:

If signal phase noise is specified (Location5), the actual phase periods vary within the specified range. The lengths of the remaining phases are adjusted so each cycle has the same overall time. This approach synchronizes several tags to simulate batch data.