Function Block Specifications - Omron CJ2 CPU - REV 10-2010 User Manual

5 Understanding Programming
5-4-3

Function Block Specifications

Defining and creat-
ing function blocks
Creating instances
FB Program Area
Storing function
blocks as files
Number of Steps Used by Function Blocks
When function blocks are used, memory is required for the following two items:
1. Function block definitions
2. Instance generation processing when function blocks are pasted into the user program as function
block instances
Therefore, the number of steps used in memory will increase with the number of instances of function
blocks created in the program (item 2).
5-44
Item
Number of function CJ2H-CPU6@(-EIP) or CJ2M-CPU@5/@4: 2,048 max.
block definitions CJ2M-CPU@3/@2/@1: 256 max.
Function block 64 characters max.
names
Variables Variable names
Variable types
Number of variables used in a
function block (not including
internal variables, external vari-
ables, EN, and EN0)
Allocation of addresses used by
variables
Actual address specification
Array specifications
Language Function blocks can be created in ladder programming language or
structured text.
Number of CJ2H-CPU6@(-EIP) or CJ2M-CPU@5/@4: 2,048 max.
instances CJ2M-CPU@3/@2/@1: 256 max.
Instance names 15,000 characters max.
20K steps
Supported only by the CJ2M CPU Units. This area is used to store
function block definitions.
Project files The project file (.cxp/cxt) Includes function block definitions and
instances.
Program/network The file memory program file (*.obj) includes function block defini-
symbol files tions and instances.
Function block Each function block definition can be stored as a single file (.cxf) for
library files reuse in other projects.
Specifications
15,000 characters max.
Input variables (Inputs), output
variables (Outputs), input-out-
put variables (In Out), internal
variables (Internals), and exter-
nal variables (Externals)
Maximum number of variables
per function block definition
• Input-output variables: 16
max.
• Input variables + input-output
variables: 64 max.
• Output variables + input-out-
put variables: 64 max.
Automatic allocation (The alloca-
tion range can be set by the
user.)
Supported
Supported (one-dimensional
arrays only and only for internal
variables and input-output vari-
ables)
CJ2 CPU Unit Software User's Manual