Rockwell Automation 1775-S4B,D17756.5.3 User Manual SCANNER/MSG HND - Manual (Page 71)

Using Symbols and Expressions
in Report Generation
Chapter 8
8Ć3
In the procedure @EASY, from chapter 8, the variable A serves as a user
symbol within the procedure, however, symbols have many purposes
which we discuss in this chapter. The PLC-3 controller supports two types
of symbols (figure 8.1):
User symbols
System symbols
The following sections explain these types of symbols.
Figure 8.1
Report Generation Symbols
Interprocedural
Applies to the
procedure in
which it is
generated plus
any other
procedure
nested together
with that
procedure.
It can be
removed with
the delete
command.
Procedural
Applies only
to the procedure
in which it is
generated.
Global
Applies to
any context.
System Symbol
Remove this type of
symbol with the delete
command.
Symbol
Symbolic Address
Generate this
type of symbol
through the
create command.
Local
Applies only to
the context
in which the
symbol is
generated.
User Symbol
Generate this symbolic
value through the
assignment command. User
symbols are removed when
you switch from command
mode control to ladder
diagram control, when a
procedure called from the
ladder diagram program
completes executing, or by
using the delete command.
Procedure Name
Generate this
type of symbol
through the
edit command.
8.2
Symbols