Allen-Bradley micrologix 1500, User Manual

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Publication 1764-UM001A-US-P
Using Real-Time Clock and Memory Modules 6-3
Memory Module
Operation
The memory module supports program back-up as well as the following features:
•
User Program and Data Back-Up
•
Program Compare
•
Data File Download Protection
•
Memory Module Write Protection
•
Removal/Insertion Under Power
User Program and Data Back-Up
The memory module provides a simple and flexible program/data transport
mechanism, allowing the user to transfer the program and data 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 transfers from a 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 remote run) mode.
To enable this feature, set the S:2/9 bit in the system status file. Refer to the
MicroLogix 1200 and MicroLogix 1500 Instruction Set Reference Manual for more
information.
Data File Download Protection
The memory module allows the user to specify individual data files in the
controller that are protected from the download procedure. This allows user data to
be saved (not overwritten) during a download.
NOTE
Data file download protection is only functional if the processor
does not have a fault and if all protected data files in the memory
module exactly match the protected data file structure within the
controller. Refer to the
MicroLogix 1200 and MicroLogix 1500
Instruction Set Reference Manual for information on protecting
data files during download.
AB Spares