Rockwell Automation Logix5000 Controllers Controller Information and Status Programming Manual - Manual (Page 17)

Chapter 2
Determine controller memory information
Depending on your type of controller, the memory of the controller may be
divided into several areas.
If you have this controller Then it stores this In this memory
1756 ControlLogix
1756 GuardLogix
1768 CompactLogix
1768 Compact GuardLogix I/O tags I/O memory
Produced / Consumed tags
Communication via Message (MSG) instructions
Communication with workstations
Communication with polled (OPC/DDE) tags that
use RSLinx software
1
Tags other than I/O, produced, or consumed tags Data and logic memory 2
Logic routines
Communication with polled (OPC/DDE) tags that
use RSLinx software 1
1769-L2x CompactLogix
1769-L3x CompactLogix
FlexLogix
DriveLogix
SoftLogix5800 These controllers do not divide their memory. They store all elements in one
common memory area.
(1) To communicate with polled tags, the controller uses both I/O data and logic
memory.
(2) 1756-L55M16 controllers have an additional memory section for logic.
To estimate how much controller memory your project requires, use the Memory
tab of the Controller Properties dialog box. For each of the memory areas of your
controller, the dialog box lets you estimate number of bytes of:
• Free (unused) memory.
• Used memory.
• Largest free contiguous block of memory.
Use the following steps to estimate the controller memory.
1. Start the Logix Designer application and open a controller project.
Introduction
Estimate memory
information offline
Rockwell Automation Publication 1756-PM015F-EN-P – October 2014 17