Delta ASD-A3-0121, User Manual

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Motion Control ASDA-A3
7-46
Revision December, 2017
7
7.1.6 PR procedure execution flow
The ASDA-A3 updates the command status every 1 ms. Figure 7.1.6.1 illustrates the PR
procedure execution flow and how the servo drive deals with PR commands. Once a PR
procedure is triggered, it goes through three units, which are PR queue, PR executor, and motion
command generator.
Priority
High Low DI:CTRG P5.007 Event(↑) Event(↓)
PR queue

Every 1 ms, issues the waiting lead PR to PR executor no matter whether the
executor has completed the commands or not.

New lead PR replaces the PR in the executor.
PR executor

Sends the paths set with motion commands to the generator (Speed Cmd, Position
Cmd).

Completes jump, write, and arithmetic operations commands.

Within 1 ms, it completes at least 20 consecutive paths with interruption functions
and without delay (If arithmetic operations which cannot be interrupted are
included, duration is determined by the operation time and will be the last
command in 1 ms).
Motion command generator

Integrates multiple commands (Sequence, interrupt, or overlap commands).

Output the integrated motion commands.
Time
Speed
Figure 7.1.6.1 PR execution flow in the ASDA-A3
 Trigger mechanism
The trigger mechanism is as mentioned in Section 7.1.5. There are three trigger methods. A PR
procedure is executed as long as a trigger signal is output. When two different trigger methods
are used for one PR procedure within the same ms, the priority is as follows: DI trigger (DI.CTRG)
> PR command trigger register (P5.007) > Rising-edge event trigger (Event ↑) > Falling-edge
event trigger (Event↓). Within this ms, commands with higher priority are executed first and then
the lower priority commands are arranged in the next ms. If three trigger commands are
generated in the same ms, the third is not added to the PR queue.