There are several ways to add SCADA measurements to SCADA Trend Graph tool.
• Drag and Drop SCADA measurements from SCADA Summary tool.
• Open SCADA Summary tool.
• Select the desired analog SCADA measurements in the SCADA Summary tool.
• Drag the selected measurements and drop then onto the graph area of a SCADA Trend Graph tool.
• Use the Add Measurements Dialog Box
Using the Add Measurements Dialog Box
To open the Add Measurements dialog box, select Add Measurements... from the SCADA Trend Graph Edit menu; this option is also available in an option from the graph's right‑click context menu.
Add Measurements Dialog Box Fields
• The Device field allows you to select a SCADA device. The following buttons are displayed to the right of the Device field:
• The Device Lookup button () is used to search for and select a device. The search is performed on the value entered in the Device field.
• The Link Device button () will populate the Device field with the device selected in the Viewer.
• The Measurements table displays the list of analog measurements for the selected SCADA device. The table is populated when a valid device alias is entered in the Device field. The table contains two columns: an unnamed column that contains check boxes used to select measurements, and the Name column that contains measurement names.
• The Real Time Trend and Historic Trend radio buttons are only editable when adding measurements to an empty graph. Otherwise, they are populated according to the currently displayed graph.
• The Real Time Trend radio button indicates that selected measurements should be added as real-time trend lines. When this option is selected, the Time Window drop-down list is available and can be used to specify the time window, going back from the current time, for the real-time trend lines.
• The Historic Trend radio button indicates that selected measurements should be added as historic trend lines. When this option is selected, the Start Time and End Time fields are available and can be used to specify the date range for the historic trend lines.
Buttons
• The OK button adds trend lines for the selected measurements to the graph and closes the Add Measurements dialog box.
• The Help button opens the online help for this topic.
• The Cancel button closes the dialog box without changing the graph.
Removing Measurements
To remove measurements, select Remove Measurements... from Edit menu in SCADA Trend Graph tool. The Remove Measurements dialog box will open.
Using Remove Measurements Dialog Box
Remove Measurements Dialog Box Fields
• The Measurements table display the list of analog measurements that are currently displayed in the SCADA Trend Graph tool. The table contains two columns: the unnamed column that contains check‑boxes used to select measurements and the Name column that contains measurement names.
Buttons
• The OK button removes trend lines for the selected measurements to the graph and closes the Remove Measurements window.
• The Help button opens the online help for this topic.
• The Cancel button closes the Remove Measurements window without changing the graph.
Adding Calculated Measurements
To add calculated measurements, select Calculate Measurements... from the SCADA Trend Graph tool Edit menu. The Calculate Measurements dialog box will open.
Using Calculate Measurements Dialog Box
Calculate Measurements Dialog Box Fields
• The Calculate Point field allows you to enter a name for the calculated point, which will be displayed in the graph legend.
• The Measurements table displays a list of the analog measurements that are currently displayed in the SCADA Trend Graph tool. The table contains two columns: the first (unnamed) column contains check-boxes that you can use to select measurements, and the Name column contains measurement names.
• The Calculation Type drop‑down list contains the calculation types that can be applied to the measurements selected from the Measurements table. The following calculation types are supported: MIN, MAX, SUM, AVG, DIF.
• If the DIF calculation type is selected, the dialog box will update to display two additional fields: First Measurement and Second Measurement. These fields allow you to select measurements from the Measurements table to use in the calculation where the Second Measurement (M2) value is subtracted from the First Measurement (M1) value.
• DIF = M1 - M2
DIF Value Selection Options
• If you select two rows in the Measurements table, and then select DIF from the Calculation Type drop-down list, the system will distribute your selections to the First Measurement and Second Measurement fields in the order selected.
• Alternatively, you can select DIF from the Calculation Type drop-down list before making any measurement selections, and then populate each field. The first selection of a Measurements table row will always populate the First Measurement field; the next selection will populate the Second Measurement field.
Selecting additional measurements will display a message stating that only two measurements can be used in the difference calculation.
Buttons
• The OK button adds trend lines for the selected calculation to the graph and closes the Calculate Measurements dialog box.
• The Help button opens the online help for this topic.
• The Cancel button closes the Calculate Measurements dialog box without changing the graph.