Omron CS1-H Series, Operation Manual

Page: 30 / 183

15
Variables Section 1-3
For example, set a boolean (BOOL) variable (bit) to either 1 (TRUE) or 0
(FALSE). Set a WORD variable to a value between 0 and 65,535 (between
0000 and FFFF hex).
If an initial value is not set, the variable will be set to 0. For example, a bool-
ean variable would be 0 (FALSE) and a WORD variable would be 0000 hex.
Retain Select the Retain Option if you want a variable’s data to be retained when the
PLC is turned ON again and when the PLC starts operating.
• Setting Procedure
Select the Retain Option .
1-3-4 Variable Properties and Variable Usage
The following table shows which properties must be set, can be set, and can-
not be set, based on the variable usage.
Note Inputs can be set as initial values, but the value of the actual input parameter
will be given priority.
1-3-5 Internal Allocation of Variable Addresses
When an instance is created from a function block definition, the CX-Program-
mer internally allocates addresses to the variables. Addresses are allocated
to all of the variables registered in the function block definition except for vari-
ables that have been assigned actual addresses with the
AT Settings prop-
erty.
Setting Internal Allocation
Areas for Variables The user sets the function block instance areas in which addresses are allo-
cated internally by the system. The variables are allocated automatically by
the system to the appropriate instance area set by the user.
Property Variable usage
Internals Inputs Outputs
Name Must be set. Must be set. Must be set.
Data Type Must be set. Must be set. Must be set.
AT (specified address) Can be set. Cannot be set. Cannot be set.
Initial Value Can be set. Can be set.
(See note.) Can be set.
Retained Can be set. Can be set.
(See note.) Can be set.
a b
15 0
15 0
t
Name Type AT Initial Value
Retained
a BOOL
Name Type AT
b YES
t
TIMER
2000.00
Name Type Initial Value
c 2000.00
Initial Value Retained
Retained AT
BOOL
BOOL
Input 0.00
Instance of function block definition A
Output 2.00
Output 5.00
Note: Variable c is an internal
variable, so it is not displayed.
Usage: Inputs
Properties:
Usage: Outputs
Properties:
Usage: Internals
Properties:
Automatic allocation of
addresses by system
Manual allocation of address to
variable in FB by AT Settings option.
Program
FB instance areas
Size (words)
Non-retained area
Retained area
Starting address
Starting address
Starting address
Starting
address
Timer area
Counter area
CIO, H, W,
D, or E Area
H, D, or E
Area
T Area
C Area
Size (words)
Size (Completion
Flags)
Size (Completion
Flags)
Example