Rockwell Automation Publication 2198-UM004D-EN-P - December 2022 369
Chapter 11 Motion Control in PR Mode
Overlap Command Execution
The Overlap function is available only with Position Type commands. When
the Overlap function (Overlap next PR =1) is used with a primary PR, the PR
queue (and PR executor) looks for the secondary PR position type so it can
merge the two Position commands while the primary PR command is
decelerating. The calculation for the merging is shown
An Interrupt command has a higher priority over an Overlap command. Thus,
when Overlap function is set in the current position command and the next
motion command is set to apply the Interrupt function, only Interrupt
function is conducted.
Figure 178 - Overlap Command
1st target speed (Spd1)
3000
---------------- -------------------------------------------
Deceleration time (Dec)
ï‚´
2nd target speed (Spd2)
3000
-------------- -----------------------------------------------
Acceleration time (Acc)
ï‚´=
IMPORTANT Do not use the DLY function when you use the Overlap function.
Because you can still select the DLY (Delay Time) when Overlap is used,
this delay occurs at the end of the primary PR motion command and
delays the second PR profile from starting.
If the Deceleration of the primary PR is the same as the Acceleration of the
secondary PR, the velocity transition between the two PRs is very smooth.
PR#2
Position
DLY=[0] 0 ms
10000 PUU
ABS
500 rpm
Acc=[0] 16.65 ms
Acc=[0] 16.65 ms
PR
executor
Motion
command
generator
Time
Speed
PR#1 (O)
Position
DLY=[0] 0 ms
5000 PUU
ABS
200 rpm
Acc=[0] 6.67 ms
Dec=[0] 6.67 ms
Deceleration time of the 1
st
command is different from
acceleration time of the 2
nd
command
(1 ms command cycle)
(1 ms command cycle)
PR#2
Position
DLY=[0] 0 ms
10000 PUU
ABS
500 rpm
Acc=[2] 6.67 ms
Dec=[2] 6.67 ms
PR
executor
Motion
command
generator
Time
Speed
PR#1 (O)
Position
DLY=[0] 0 ms
5000 PUU
ABS
200 rpm
Acc=[0] 6.67 ms
Dec=[0] 6.67 ms
Deceleration time of the 1
st
command is identical to
acceleration time of the 2
nd
command
(1 ms command cycle) (1 ms command cycle)
Command with Delay - Acceleration and Deceleration Time are Identical
Overlap Command - Acceleration and Deceleration Time are Different
PR
executor
Motion
command
generator
Overlap Command - Acceleration and Deceleration Time are Different
Command with Delay - Acceleration and Deceleration Time are Identical
Motion
command
generator
PR
executor
Deceleration time of the 1st command is different
from
Deceleration time of the 1st command is identical to
acceleration time of the 2nd command
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