Omron CS1-H Series, Operation Manual

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4
Introducing the Function Blocks Section 1-1
Note The structured text (ST language) conforms to the IEC 61131-3 standard, but
CX-Programmer Ver. 5.0 supports only assignment statements, selection
statements (CASE and IF statements), iteration statements (FOR, WHILE,
REPEAT, and EXIT statements), RETURN statements, arithmetic operators,
logical operators, comparison functions, numeric functions, and comments.
For details, refer to
Appendix B Structured Text (ST Language) Specifications.
1-1-3 Files Created with CX-Programmer Ver. 5.0
Project Files (*.cxp) and
File Memory Program
Files (*.obj) Projects created using CX-Programmer that contain function block definitions
and projects with instances are saved in the same standard project files
(*.cxp) and file memory program files (*.obj).
The following diagram shows the contents of a project. The function block def-
initions are created at the same directory level as the program within the rele-
vant PLC directory.
Functions not
supported by
CX-Program-
mer Ver. 4.0
or earlier. Defining
and creat-
ing func-
tion blocks Number of
function block
definitions CS1-H/CJ1-H CPU Units:
• Suffix -CPU44H/45H/64H/65H/66H/67H: 1,024 max. per CPU Unit
• Suffix -CPU42H/43H/63H: 128 max. per CPU Unit
CJ1M CPU Units:
• CJ1M-CPU11/12/13/21/22/23: 128 max. per CPU Unit
Function
block names 64 characters max.
Variables Variable names 30,000 characters max.
Variable types Inputs, Outputs, Internals, and Externals
Number of I/O variables in
function block definitions 64 max. (not including EN and ENO)
Allocation of addresses
used by variables Automatic allocation (The allocation range can
be set by the user.)
Actual address specifica-
tion Supported
Array specifications Supported (one-dimensional arrays only)
Language Function blocks can be created in ladder programming language or structured
text (ST, see note).
Creating
instances Number of
instances CS1-H/CJ1-H CPU Units:
• Suffix -CPU44H/45H/64H/65H/66H/67H: 2,048 max. per CPU Unit
• Suffix -CPU42H/43H/63H: 256 max. per CPU Unit
CJ1M CPU Units:
CJ1M-CPU11/12/13/21/22/23: 256 max. per CPU Unit
Instance
names 30,000 characters max.
Storing
function
blocks as
files Project files The project file (.cxp/cxt) Includes function block definitions and instances.
Program files The file memory program file (*.obj) includes function block definitions and
instances.
Function
block library
files Each function block definition can be stored as a single file (.cxf) for reuse in
other projects.
Item Specifications