Watlow LogicPro - Manual (Page 202)

Chapter 12: Function Blocks LogicPro User’s Guide
186 Watlow Anafaze Doc.# 28002-00 Rev 3.00
NOTE! If an output Variable in a logic Program sets a val-
ue using an IO Driver and IO Physical Address,
the associated register in the controller cannot be
written to by the closed-loop control program, an
HMI, or any other device.
Variable Types
Variables in a logic program can be declared to be one of four
types. Table 12.1 describes the options for Variable Type.
Table 12.1 Variable Types
NOTE! The IO Driver and IO Size lists are sensitive to the
choice you make in the Type list.
Type Description
BOOL
Boolean variables can hold values of 0 or 1 only
(1 bit). This is the type of variable to create to
associate with coils in a ladder diagram or transi-
tions in an SFC. Choose BOOL for variables that
will be associated with digital I/O. A BOOL vari-
able always has its IO Size set to BIT.
INT
Integer variables can hold values from -32,768 to
32,767 (16 bits). Use this variable type with ana-
log I/O and most closed-loop control parameters
such as setpoint. Always choose WORD for the
IO Size of an INT variable
LONG
Long integer variables can hold values from -
2,147,483,648 to -2,147,483,647 (32 bits). LONG
variables are always internal. You cannot associ-
ate a LONG variable with an I/O point or closed-
loop control parameter.
REAL
Real variables (also known as floating point) hold
positive and negative real numbers between -
3.4e38 and 3.4e38. REAL variables are always
internal. You cannot associate a REAL variable
with an I/O point or closed-loop control parameter.