The Data Log Trend Display shows Historical Trend Data and Real-Time Trend Data. Every Second a new data point is entered in the Trend Window. Tag Values are plotted Vertically on the Y-axis. Time is plotted horizontally on the X-axis. This is similar to Strip Chart Trend Recorders in control rooms, commonly associated with Distributed Control Systems (DCS).
Figure 9.11 Data Log Trend Display
The Data Log Trend Display can be viewed
from Data Log
Trend List using the Toolbar or F4 function key
or a pushbutton with the <DIALOG>DLOGTRD
keymacro. The Alarm Summary can also be called using the
(Right Click->Goto ->Data Log Trend) and from the Point Goto Dialog Box.
Power Users, General Users and the admin account can view the Data Log Trends through a Web Browser. Restricted users cannot view the Data Log Trends through a Web Browser. All users can view the Data Log Trends locally on the SCADA node using ViewDAQ.
For a complete description the pushbuttons and functions of the Data Log Trend Display, please refer to section 6.2 Data Log Trends.
The Data Log Trend Display is a pre-built template display supplied with Web Access. Hundreds of 'Trend Groups" can be viewed through this one display. It can be customized by engineers and technicians using DRAW. How your Data Log Trend Colors, Flashing, Fonts, behave may vary based on how (or if) the Dlogtrd.Bxx (and Dlogtrd.dxx) on your system is modified.
The Data Log Trend must be named with the *.BXX extension to operate properly. If you modify the source file (DLOGTRD.DXX), be sure to re-enter the DLOGTRD.BXX when you use the Save Bgr function.
DLOGTRD.DXX is most easily accessed using DrawDAQ on the local SCADA node. DrawDAQ allows you to change the browse settings to *.dxx, enabling you to see all the default Template Display source files. Note that User Built displays have the *.DRW extension. System Template Displays have the *.DXX extension.
If you do modify the System Template Displays, you should consider either saving the source file as the *.DRW extension, or use another name. This will prevent your modified files from being overwritten accidentally.