User`s guide

Logical (Boolean) Expressions
The next two sections discuss program control structures whose execution depends on an
expression or variable that takes on a Boolean value (a variable that is either true or false, or
an expression that resolves to true or false). An expression can take into account any number
of variables or digital input signals as long as the final resolution of the expression is a Boolean
value. In V+, any number (real or integer) can satisfy this requirement. Zero is considered
false; any nonzero number is considered true. There are four system constants, TRUE and ON
that resolve to -1, and FALSE and OFF, that resolve to 0.
Examples of valid Boolean expressions:
y > 32
NOT(y > 32)
x == 56
x AND y
(x AND y) OR (var1 < var2)
-1
For details on V+ relational operators, see Relational Operators on page 111.
Logical (Boolean) Expressions
V+Language User's Guide, v17.0
Page 128