Rockwell Automation Publication 2080-UM002L-EN-E - November 2021
25
Chapter 2 About Your Controller
Insufficient Controller Memory Example
Limitations of RMC
Take note of the following limitations when using the Run Mode Change
(RMC) feature:
•
Configuration changes cannot be made (for example, change filter
times).
•
Up to 2KB of logic (approximately 150 boolean instructions) and user
variables and can be added for each Test Logic.
•
Total memory allocated for RMC (cumulative of all Test Logic Changes)
can be increased from 2KB to 8KB, but the 2KB limit for logic and user
variables per Test Logic remains.
•
Up to 20 POU (Program Organizational Units) can be added for each
change (for example, if you currently have 5 POU, you can add 20 more
for a total of 25 POU).
•
If a User Defined Function Block is modified that changes the local
variables, the local variables will be reinitialized or reset to zero and a
warning message will be shown during the build. If you want to reapply
the initial value, right-click on the UDFB and select Refactor
→
Reset
Initial Values of Instances.
•
RMC is not possible after doing a Discover Project operation if a new
module is detected because the configuration has changed.
•
Exchange files cannot be imported when in RMC because it is considered
a configuration change.
•
Making changes to the display configuration (for example, hiding
comments) are treated as logic changes and require you to build the
project.
•
Global variables cannot be deleted or modified in RMC, but can be added.
To delete or modify a global variable, Connected Components
Workbench software must be disconnected from the controller.
•
When using CIP™ messaging in RMC, setting the CIPTARGETCFG data
type parameter ConnClose to TRUE has no effect. The Ethernet session
does not close immediately upon successful messaging and you have to
wait for the connection to timeout after 60 seconds. This applies to
Connected Components Workbench software version 9 or earlier
projects. For version 10 or later projects, the CIP connection timeout is
configurable.
See
Use Run Mode Change on page 242
for an example on how to use this
feature.
WARNING:
If you delete the output rung when in Run Mode Change and accept the
changes, the output on the controller will remain ON.
Controller Memory
(for User P Data)
RMC Memory
(Default size = 2KB)
Error will occur due to insufficient
controller memory remaining
Free RMC memory
Used memory
