Rockwell Automation 57C423 Common Memory Module - Manual (Page 38)

FĆ2
Appendix F
(Continued)
The Common Memory Module Is In Any
Even Slot Other Than 0
In the following, assume the Common Memory module is in slot 2 and the single
Processor module in the rack is in slot 1. Recall that in this configuration, common
variables, as well as local variables, are being stored on the Processor module.
Status of Data
Common
Action
App.
Task
Deleted?
App.
Task
Status NonVol Vol I/O Local
Replace 57C413A with
Same or new 57C413A
ąAt power up NO STOP Data OK Zero Lost
(Random)
Data OK
Replace 57C413A with
New 57C413B or
57C423
ąAt power up NO STOP Data OK Zero Zero* Data OK
Replace 57C413A with
used 57C413B or
57C423 (module may
contain data from
another application)
ąAt power up NO STOP Data OK Zero Value from
programmed
module at
same
address*
Data OK
Replace 57C413B or
57C423 with New
57C413B
ąAt power up NO STOP Data OK Zero Zero* Data OK
Replace 57C413B or
57C423 with used
57C413B or 57C423
(module may contain
data from another
application)
ąAt power up NO STOP Data OK Zero
Value from
used module
at same
address*
Data OK
Replace battery on
57C413B or 57C423 and
return same module to
rack
ąAt power up*** NO STOP Data OK Zero Data OK Data OK
* To ensure your application task does not access old or incorrect data, create
a BASIC task to write zeroes to each register location before you run any
other application tasks.
** Assumes superĆcapacitor has maintained memory on the module during the
time required to replace the battery.