Rockwell Automation 1763 MicroLogix 1100 Programmable Controllers User Manual - Manual (Page 146)

Publication 1763-UM001D-EN-P - March 2011
144 Using Real-Time Clock and Memory Modules
Data File Download Protection
The memory module supports data file download protection. This allows user
data to be saved (not overwritten) during a download.
Memory Module Write Protection
The memory module supports write-once, read-many behavior. Write
protection is enabled using your programming software.
Removal/Insertion Under Power
The memory module can be installed or removed at any time without risk of
damage to either the memory module or the controller. If a memory module is
installed while the MicroLogix 1100 is executing, the memory module is not
recognized until either a power cycle occurs, or until the controller is placed in
a non-executing mode (program mode, suspend mode or fault condition).
Memory Module Information File
The controller has a Memory Module Information (MMI) File which provides
status from the attached memory module. At power-up or on detection of a
memory module being inserted, the catalog number, series, revision, and type
are identified and written to the MMI file. If a memory module is not attached,
zeros are written to the MMI file. Refer to the MicroLogix 1100 Instruction Set
Reference Manual, publication 1763-RM001, for more information.
TIP
Data file download protection is only functional if the
processor does not have a fault, size of all protected
data files in the memory module exactly match the
size of protected data files within the controller, and
all protected data files are of the same type. See
“Protecting Data Files During Download” in the
MicroLogix 1100 Programmable Controllers
Instruction Set Reference Manual, Publication
1763-RM001.
IMPORTANT
Once set, write protection cannot be removed. A
change cannot be made to the control program
stored in a write protected memory module. If a
change is required, use a different memory module.