Super Systems SD Recorder II - Manual (Page 18)

Super Systems Inc. Page 18 of 50 SD Recorder II Operations Manual
Expression Editor for Special Pen
Variable Selector – A Tree view of the
Tag data from which tags can be selected
and added to the “selected variables” list.
This tree will be a list of the configured
connections, groups and tags.
Selected Variables – A list of variables
that may be used in the special pen's
expression. When using the editor to edit a
previously created special pen, this list will
be initialized with the tags used in the expression. The value displayed in this list is a
“snapshot” and will change only when the tag is added to the variable list or when
the “Check syntax and evaluate” button is clicked and the variable is part of the
expression. A Right click on a row will insert the variable into the expression (you
may also double click on the row).
Check Syntax and Evaluate button – Clicking this button will check the syntax
and evaluate the expression. The result will be found in the “Result” box.
Save Expression button – Saves the expression to the pen's expression.
Expression view box – Displays the expression. You may also edit the expression
in this box.
Result box – Displays the result when clicking “Check Syntax and Evaluate”.
Operators and Constants – Usual math operators.
Logical Operators – Logical operators always result in 0 if false and 1 if true.
Math Functions – Usual math and trig functions.
Logical Functions
IIF – IIF(x,y,z) is an “if-then-else” construct. If x is true then return y else return
z. IIF functions can be nested to a depth of 8.
Bit – Bit(x,y) returns 1 if bit y of value x is ON. Otherwise, it returns 0.
Special Functions – SRound is a special rounding function used with load
thermocouple values.
NOTE: In the US, the point is used as the decimal separator; in many other locales,
the comma is used as the decimal separator. When the point is used as a decimal
separator, the comma is used as a variable separator. When the comma is used as a
decimal separator, the semicolon is used as a variable separator.
Example: In the US, IIF(t10001>0, 12.5, 9.2) is a valid expression,
while in France the expression would be IIF(t10001>0; 12,5; 9,2)