Delta ASDA-A3 Series User Manual page 454

ASDA-A3
 PR queue
The triggered PR path is the lead PR. The PR group it leads goes into the PR queue to wait for
prioritization. In each ms, the servo drive sends the lead PR and the PR group it leads to the PR
executor with a first-in first-out method no matter whether a PR path is being executed.
Therefore, as long as a PR path is triggered, the PR queue collects it and sends it to the
executor.
 PR Executor
Once the PR executor receives the lead PR and its PR group, the PR group that is being
executed will be replaced immediately. If a PR group includes motion commands, such as
Speed commands and Position commands, then the PR executor sends them to the motion
command generator. PR paths with Write or Jump commands are complete at the moment
when the PR executor reads the command, and thus they do not enter the generator. The
arithmetic operations commands are executed when entering the PR executor; however, the
execution time varies with the computing duration and the next command cannot interrupt
during computing. The PR executor can consecutively complete at least 20 PR paths with
interrupt commands (INS) (without delay times) within 1 ms. If there is a PR path that has not
completed within 1 ms, and a new PR group is sent to the executor by the queue, the new PR
group then replaces the previous PR group. In other words, instead of executing the PR group
that hasn't been completed, the executor starts executing the new PR group. However, if a new
PR group hasn't been sent to the executor yet after 1 ms, the executor continues to execute the
unfinished PR path.
 Motion command generator
Motion commands include the Speed and Position commands. The PR executor sends these
types of commands to the motion command generator. This generator has a buffer for
temporarily storing the next motion command and all motion commands are integrated here.
Motion commands can be executed as long as they enter the generator. If another motion
command (with interrupt setting) also enters the generator, it is integrated with the current
command in the generator and the integration is based on the motion command settings. The
settings include whether multiple motion commands are sequence commands and whether they
are set with the Overlap or Interrupt function. All integration varies with each PR path setting.
Sequence command
The configurable motion commands for PR paths are Position and Speed commands. A
sequence command is a motion command without an Overlap or Interrupt function. The
following command starts to be executed only after the delay set in the previous command.
Regarding Position commands, the delay time starts to count after the target position is
reached. For Speed command, the delay time counting starts after the target speed is reached.
Motion Control
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