KEYENCE SR-700 Series - Manual (Page 6)

6 E SR SCRIPT RM
3-1
Calculation
This describes arithmetic operators used for general calculations.
Arithmetic operator
Format
On the left-hand side and the right-hand side of each operator, write an expression
using numerical values or variables of numerical values.
Important If character strings are assigned to variables and they cannot be
converted to numerical values during calculation, an error will
occur on execution.
Reference To obtain only the integer part of division result, use arithmetic function
math.floor.(Page 11)
3-2
Comparison
This describes comparative operators used when comparing numerical values or logical values.
Comparative operator
Format
On the left-hand side and the right-hand side of each operator, write numerical
values, variables of numerical values or arithmetic expression.
Important Comparison is also possible by assigning character strings to
variables. However, when variables are evaluated by conditional
expression, and if they cannot be converted to numerical values,
an error will occur on execution.
Arithmetic
operator
Meaning
+ Addition
- Subtraction
* Multiplication
/ Division
% Remainder (from division)
^ Power
Example
A = B + 1 Assigns the result of variable B plus 1 to variable A.
Example
Comparative operator Meaning
< smaller
<= smaller or equal
> greater
>= greater or equal
== equal
~= different
Example
Examples of calculations and results (a=5.5, b=2)
Arithmetic expression Result
a + b 7.5
a - b 3.5
a * b 11
a / b 2.75
a % b 1.5
a ^ b 30.25
Examples of calculations and results (a=10, b=1)
Arithmetic expression Result
a > b true
a < b false
a == 10 true
a ~= 10 false
3-3
Combination of condition
This describes logical operators used when combining conditions.
Logical operator
Format
3-4
Character string
concatenation
This describes concatenation operators used to connect one character string to
another.
Concatenation operator
Format
Logical operator Meaning
and
Logical AND operator: If the first argument is false or nil, the value is returned.
If not, the second argument is returned.
or
Logical OR operator: If the first argument is different from false or nil, the
first argument is returned. If not, the second
argument is returned.
not
Logical NOT operator: If the next value is false or nil, true is returned. If not,
false is returned.
Example
variable 1 .. variable 2
Expresses using 2 periods ".." between
variables.
Example
local a = "Keyence"
Declares variable a and initializes with character
string "Keyence".
local b = "Auto-ID"
Declares variable b and initializes with character
string "Auto-ID".
local c Declares variable c.
c = a .. b Assigns values after a and b are connected.
Value of c: "KeyenceAuto-ID"
Examples of calculations and results
Arithmetic expression Result
true and true true
true or true true
true and false false
true or false true
not false true
not true false
10 or 30 10
nil or 30 30
false or nil nil