31
Function Blocks
Section 1-5
Different Processes Easily
Created from a Single
Function Block
Many different processes can be created easily from a single function block by
using input variables for the parameters (such as timer SVs, control con-
stants, speed settings, and travel distances) in the standard process.
Reduced Coding Errors
Coding mistakes can be reduced, because blocks that have already been
debugged can be reused.
Data Protection
The local variables in the function block cannot be accessed directly from the
outside, so the data can be protected. (Data cannot be changed unintention-
ally.)
Improved Reusability
through Programming
with Variables
The function block's I/O is entered as local variables, so the data addresses in
the function block do not have to be changed as they do when copying and
reusing a program section.
Creating Libraries
Processes that are independent and reusable (such as processes for individ-
ual steps, machinery, equipment, or control systems) can be saved as func-
tion block definitions and converted to library functions.
The function blocks are created with local variable names that are not tied to
physical addresses, so new programs can be developed easily just by reading
the definitions from the file and placing them in a new program.
Nesting Multiple
Languages
Mathematical expressions can be entered in structured text (ST) language.
Nesting function blocks is supported for CX-Programmer Ver. 6.0 or higher.
For example, it is possible to express only special operations in ST language
within a function block in a ladder diagram.
For details on using function blocks, refer to the
CX-Programmer Ver. 7.0
Operation Manual: Function Blocks
(Cat. No. W447).
Function block (ladder language)
Call (Nesting)
Function block (ST language)
Summary of Contents for CP1L-L14D Series
Page 2: ...CP1L L14D CP1L L20D CP1L M30D CP1L M40D CP1L CPU Unit Operation Manual Revised June 2007...
Page 3: ...iv...
Page 9: ...x...
Page 13: ...xiv TABLE OF CONTENTS...
Page 21: ...xxii...
Page 33: ...xxxiv Conformance to EC Directives 6...
Page 65: ...32 Function Blocks Section 1 5...
Page 153: ...120 CP CPM1A series Expansion I O Unit Wiring Section 3 6...
Page 523: ...490 Troubleshooting Unit Errors Section 9 4...
Page 531: ...498 Replacing User serviceable Parts Section 10 2...
Page 563: ...530 Auxiliary Area Allocations by Function Appendix C...
Page 611: ...578 Auxiliary Area Allocations by Address Appendix D...
Page 638: ...605 Connections to Serial Communications Option Boards Appendix F Connecting to Unit...
Page 639: ...606 Connections to Serial Communications Option Boards Appendix F...
Page 669: ...636 Index...
Page 671: ...638 Revision History...