Historical Trend Displays - Siemens SIMATIC PCS 7 OSx Operator's Manual

Displaying Trend Data (continued)
Historical Trend
Displays
4-4
Trends
Historical trend displays are similar to real-time trend displays, but are not
updated.
The historical trend display plots the data for the time range you specify. To
change the start or end time for a trend, select the
historical data appears compressed if the data changed rapidly during the
specified time range. Historical data does not appear at all if the
tag/attribute pair was not configured for trending during the specified time.
A trend line is magenta if the tag/attribute pair was not scanned during the
requested time period.
To obtain an exact value at a given time, move the cursor into the graph
area, placing it at the time needed, and click the left button. A vertical line
appears at the selected time and a pop-up list displays values for each tag in
the plot (Figure 4-2).
A historical trend gives an approximate viewing-window time for its data.
The data is correct, but the operator may not get to the endpoints of the
trend with the dipstick. Therefore, make sure that the time ranges are
adequate for the data that you want to view.
target. The
Change Time
SIMATIC PCS 7 OSx 4.1.2 Operator