Allen-Bradley Kinetix 5100 2198-E1004-ERS, User Manual, Page: 254 / 500

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Rockwell Automation Publication 2198-UM004A-EN-P - October 2019
Chapter 11
Motion Control in PR Mode
How these four monitoring variables work is shown in Figure 83 . 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 command 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.
Figure 83 - Timing Diagram of PR Mode Monitoring Variables
The detailed command behavior of each stage is illustrated in Figure 84 . Cmd_E
is the endpoint specified by the command; its setting is completed once the PR
command is triggered. Fb_PUU is the feedback position, which is motor's actual
position. For example, Cmd_O is the target of this command section and
Err_PUU is the deviation between target position and feedback position.
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