Delta ASD-A3-0121, Руководство пользователя

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Motion Control ASDA-A3
7-6
Revision December, 2017
7
7.1.2 Monitoring variables of PR mode
PR mode provides four monitoring variables for the servo command and feedback: command
position (PUU), PR command end register, feedback position (PUU), and position error (PUU).
These are described below:
1. Command position (PUU): monitoring variable code 001. The target position of the motion
command generated per scan cycle during servo operation (updated every 1 ms),
simplified as Cmd_O (Command Operation).
2. PR command end register: monitoring variable code 064. The target position of the PR
command, simplified as Cmd_E (Command End). When a command is triggered, the servo
drive calculates the target position and then updates the PR command end register.
3. Feedback position (PUU): monitoring variable code 000. The feedback position
(coordinates) for the motor, simplified as Fb_PUU (Feedback PUU).
4. Position error (PUU): monitoring variable code 002. The deviation between the command
position (PUU) and the feedback position (PUU), simplified as Err_PUU (Error PUU).
How these four monitoring variables work is shown in Figure 7.1.2.1. After the servo issues a
Position command, the servo sets the position of Cmd_E once the target position data is
acquired. The motor operates to the target position based on the PR path setting. Cmd_O
calculates the amount of command deviation in each fixed cycle and sends it to the servo drive,
where it is treated as a dynamic command. Fb_PUU is motor‟s feedback position and Err_PUU
is the deviation of Cmd_O minus Fb_PUU.
Err_PUU
Before
command
issued
Fb_PUU
Cmd_O
Cmd_E
Err_PUU
Fb_PUU
Cmd_O
Cmd_E
Err_PUU
Fb_PUU
Cmd_O
Cmd_E
Err_PUU
Fb_PUU
Cmd_O
Cmd_E
Err_PUU
Fb_PUU
Cmd_O
Cmd_E
Command in
execution
Command
completed
Motor
positioned
After
command
issued
Figure 7.1.2.1 Timing diagram for PR mode monitoring variables