Rockwell Automation 1766-Lxxxx MicroLogix 1400 Programmable Controllers User Manual - Manual (Page 163)

Rockwell Automation Publication 1766-UM001H-EN-P - May 2014 121
Using Real-Time Clock and Memory Modules Chapter 6
User Program , User Data, Datalog and Recipe Back-up
The memory module provides a simple and flexible program, data, DataLog, and
Recipe transport mechanism, allowing the user to transfer the program, data,
DataLog and Recipe to the controller without the use of a personal computer and
programming software.
The memory module can store one user program at a time.
During program transfers to or from the memory module, the controller’s RUN
LED flashes.
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 1400 Programmable Controllers Instruction Set
Reference Manual, Publication 1766-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.
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 1400 Programmable
Controllers Instruction Set Reference Manual, Publication
1766-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.