Emerson 3051S Dokumentacja Pobierz pdf (Strona 94)

Reference Manual

00809-0200-4801, Rev CA

July 2010

Rosemount 3051S

6-16

Follow through the “Add History Collection” dialog (Figure 6-14), to add the

parameter to the DeltaV Historian with the desired sampling period,

compression, etc. By default the sampling period is 60 seconds, as shown in

a. of Figure 6-14. However, there are many diagnostics applications where

one may want to look at changes in the standard deviation much faster than

this. In that case, you will want to set the sampling period to something

smaller.

When adding a standard deviation for history collection in DeltaV, it is

recommended that you not use the default data compression settings. By

default, the DeltaV Historian will log a new data point only when the process

value deviates by 0.01 or more. There are many diagnostics applications

where it is useful to look at changes in the standard deviation that are smaller

than this. Therefore, it is recommended that when logging the standard

deviation, either the Data Compression should be disabled (by unchecking

the appropriate box in b. of Figure 6-14 on page 6-16) or the Deviation (EU)

should be set to a much lower value, for example, 0.001 or 0.0001.

Figure 6-14. DeltaV Add History

Collection: a.) General

Configuration b.) Advanced

Configuration

Refer to the DeltaV Books Online for more details on the DeltaV Continuous

Historian.

After the SPM value has been saved to the historian, when the DeltaV

Process History View is opened for the selected parameter, the graph will be

populated with the historical data currently in the database (Figure 6-15).

1 2 ... 89 90 91 92 93 94 95 96 97 98 99 ... 239 240

Brak uwag

Emerson 3051S Dokumentacja Strona 94