Rockwell Automation Publication 2198-UM004D-EN-P - December 2022 359
Chapter 11 Motion Control in PR Mode
PR Queue
The triggered PR command is the lead PR. The PR and its container Group are
organized and prepared to be sent to the PR Executor. In each ms, regardless
of another PR being queued, the servo drive sends the lead PR and its PR group
to the PR executor. Therefore, as long as a PR command is triggered, the PR
queue collects the command and sends the command to the executor.
PR Executor
Once the PR executor receives the lead PR, the PR group in execution is
replaced immediately. If a PR group includes motion commands, such as
speed commands and position commands, the PR executor sends them to the
Motion Command Generator. If the lead PR contains write or jump
commands, they are completed immediately when the PR executor processes
the lead PR. These commands do not enter the Motion Command Generator.
Any arithmetic based operations (Statement commands) are executed
immediately when entering PR executor. Depending on the expression, the
execution times vary and these commands cannot be interrupted until they are
completed.
The PR executor can consecutively complete a minimum of 20 PR commands
with interrupt commands (INS) and without a delay time setting within 1 ms.
If there is a PR command that hasn't been completed within 1 ms and a new PR
group has been sent to the executor by the queue, the new PR group then
replaces the previous one.
Motion Command Generator
Motion commands include speed and position types. The PR executor sends
this command type to the Motion Command Generator. This generator has a
buffer for creating the motion profile. This generator includes the capability to
modify the existing cycle profile (overlap, interrupt, and Proceed to next).
Motion commands can be executed as soon as they enter the generator. If
other motion commands (that are merge capable) enter the generator, it is
integrated with the existing command in the generator. This integration is
based on the PR settings.
Sequence Command Execution
Commands that you can configure are position and speed commands. A
sequence command is a motion command without an overlap or interrupt
function. When you use position commands, the Delay Time begins timing
when the target position is reached. When you use speed commands, the Delay
Time begins timing after the target speed is reached.
To Next Page
Loading...
Need help?
General
