CatNet Systems CH1 Help

General Introduction Toolbar Device Tree Tutorial User Groups Users Templates Control Points Graphics Viewing Editing Components Schedules Viewing/Editing Trends Viewing/Editing Alarms Viewing Editing Runtimes Viewing Editing Calculations Viewing/Editing 
Calculation Editor
Calculations read points from one or more devices and performs a calculation on them, such as average, minimum or maximum. Custom calculations may also be used. Calculations may be used on graphics, trends, alarms and even other calculations just like physical points. Points must be dragged from the device tree and dropped in the points list. Drop every point that will be part of the calculation. The order of the points is generally not important unless a custom function is used. Function
Select the function to perform on the points in the point list. For example, to average three temperatures, drag the three temperature points to the point list and select "Average".
Custom functions are also supported by selecting "Custom" and entering a calculation in the "Postfunction Calculation" below. Postfunction Calculation
The postfunction calculation is used to perform an additional calculation on the result of the function, or to specify a custom function.
Example: To have this Calculation point equal the average of three temperatures, but converted from Fahrenheit to Celsius, add the three points to the list, select "Average" and enter the following in the postfunction calculation: (@R32)/1.8 The result of the calculation function selected above (the average temperature in this example) will be inserted in to the postfunction calculation where the @R code is located. To use a completely custom function, select "Custom" as the function and then enter a postfunction calculation with @Vx codes where the point values from the list should appear. @V1 is the value of the first point in the list, @V2 the second point, etc. Example: To get the sum total of three points and subtract 100 from it, enter the following in the postfunction calculation: (@V1+@V2+@V3)100 Several builtin subfunctions are available to call from within the postfunction calculation:
CtoF(min(@V1,@V2,@V3)) Refresh Button
The refresh button will update the value and status shown on the screen. If changes have been made, they must first be saved by clicking the "Apply" button.
Units
This is the engineering units to display for this Calculation when used on graphics.
Precision
This is the number of digits to the right of the decimal point to display for this Calculation when used on graphics.

Copyright 2008, CatNet Systems 