Product data

31
Modicon
™
Quantum
™
Ethernet I/O
automation platform
Unity
™
Pro software
Small / Medium / Large / Extra Large / XLS
DFB user function blocks
Using Unity
™
Pro software, users can create their own function blocks for specic
application requirements on Modicon
™
M340
™
, Premium
™
and Quantum
™
platforms.
Once created and saved in the library, these user function blocks can be reused as
easily as EFBs (Elementary Function Blocks).
These user function blocks can be used to structure an application. They are used
when a program sequence is repeated several times in the application or for freezing
a standard programming routine. They can be read-only or read/write. They can be
exported to other Unity Pro applications.
Using a DFB in one or more applications:
Simplies program design and entry b
Improves program readability and understanding b
Facilitates program debugging (variables handled by the DFB are identied in the b
data editor)
Enables the use of private variables specic to the DFBs that are independent of b
the application
A DFB is set up in several stages:
DFB is designed by assigning a name, a set of parameters (inputs, outputs, public b
and private internal variables) and a comment to it via the data editor.
Code is created in one or more sections of the program, with the following b
languages selected according to requirements: Structured Text, Instruction List,
Ladder or Function Block Diagram (ST, IL, LD or FBD).
DFB may be stored in a library with an associated version number. b
DFB instance is created in the data editor or when the function is called in the b
program editor.
This instance is used in the program in the same way as an EFB (the instance can b
be created from within the program).
Functions (continued)
Design
Creating the code
Use within the program