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Rockwell Automation Publication 2080-UM002L-EN-E - November 2021
Chapter 2 About Your Controller
RMC is useful when the user is developing a project by incrementally adding
small changes to the logic and immediately wants to see the effects of the
changes on the machine. With RMC, since the controller stays in remote run
mode, the controller logic and machine actuators will not have to constantly
reinitialize, which can occur if the controller is switched to remote program
mode (for example, first scan bit is checked in program logic to clear outputs).
When user is editing, building, and downloading a project without using RMC,
a full build of the entire controller project is performed and also a full
download of the project is performed. During RMC an incremental build is
performed and only incremental changes are downloaded to the controller.
RMC is performed incrementally at the end of every program scan in order to
prevent a large delay in the program scan. This adds up to an additional 12 ms
to the scan time. For example, if the program scan is normally 10 ms, it may
increase to 22 ms during RMC until the update is finished. Similarly user
interrupts may be delayed.
A new global variable __SYSVA_PROJ_INCOMPLETE has been added to
indicate when Run Mode Changes are being made. This can be used to notify
personnel on the HMI that there are uncommitted changes in the controller.
IMPORTANT
Micro820/Micro830/Micro850 controller firmware revision 8.xxx or higher is
also required to use Run Mode Change.
IMPORTANT
Do not disconnect from the controller after performing Run Mode Change, do
a full build, and try to reconnect. Connected Components Workbench
software treats the project in the controller as different from the project in
Connected Components Workbench software, and ask to either upload or
download even though the logic is identical.
Example of the Benefits of Using RMC – 20% Reduction in Download Time
Number of
Changes
Time to Perform Conventional
Download (seconds)
Time to Test Logic and
Accept Changes (seconds)
1
36
29
5
180
130
10
360
255
Memory size of project used for comparison:
Data = 14784 bytes; Program = 2352 bytes
Note: The duration starts when the RMC button is clicked while connected to the controller and ends when the accept is
finished. For example:
1. When connected to the controller, click RMC
2. Modify program
3. Click Test Logic
4. Click Accept to finish, or click Test Logic to make another change
ATTENTION:
Use extreme caution when you use Run Mode Change. Mistakes
can injure personnel and damage equipment. Before using Run Mode Change:
•
A
ssess how machinery will respond to the changes.
•
N
otify all personnel about the changes.
