Symbolic addressing – Rockwell Automation 9323-S5500D A.I. SERIES MICROLOGIX 1000 AND PLC-500 SOFTW User Manual
Page 100
MicroLogix 1000 and PLC-500 A.I. Series Software Reference
4-32
Symbolic Addressing
PLC-500 A.I. allows you to assign a symbol name to a word or bit address, and use the
symbol instead of the address during programming. A symbol is a description of the
data the word or bit address represents, and can be up to 15 characters in length. To
create a symbol, simply type a new symbol name in response to a prompt for an
address. (See
Auto Addressing
on page
4-34
for more details.) You can assign symbols
to both direct and indirect addresses.
Note
The following characters may
NOT
be used in a symbol name:
* ? . / : # $ [
]
. Characters from the Extended ASCII character set are also invalid in symbol
names. (These characters are specified by holding down the
[Alt]
key while typing a
number on the numeric keypad.)
Symbol Help
Anywhere the system prompts you for an address, you can obtain
symbol help
, which
allows you to select from a list of existing symbols. Press
[Ins]
to display the symbol
help screen.
The symbol help screen shows the symbol name, data file type, address type (word or
bit) and description text. Position the cursor on a symbol and press
[Enter]
to select
that symbol/address.