Rockwell Automation 1762-Lxxxx MicroLogix 1200 Programmable Controllers - Manual (Page 92)

Publication 1762-UM001G-EN-P - March 2011
6-4 Use Real-time Clock and Memory Modules
Program Compare
The memory module can also provide application security, allowing you to
specify that if the program stored in the memory module does not match the
program in the controller, the controller will not enter an executing (run or
test) mode. To enable this feature, set the S:2/9 bit in the system status file. See
‘Status System File’ in the MicroLogix 1200 and 1500 Programmable
Controllers Instruction Set Reference Manual, Publication 1762-RM001 for
more information.
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 1200 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).
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 1200 and 1500 Programmable Controllers
Instruction Set Reference Manual, publication
1762-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.