Siemens SIMOTION Function Manual page 74

Basics of Path Interpolation
2.14 Motion sequence on the path object
In the simplest case, after the synchronization, the kinematic end point moves with a defined
point in the OCS and so with a point located on the conveyor. Furthermore, after the
synchronization in the coupled OCS, linear, circular or polynomial paths can also be
followed.
The _enablePathObjectTrackingSuperimposed() command is used to synchronize the
kinematic end point with an OCS coupled with the motion sequence reference value (e.g.
position of a conveyor). Some of the arguments specified with the command:
● Synchronization mode (synchronizingMode)
● The synchronization position (position)
The following applies for both synchronization modes:
● The synchronization on the conveyor belt occurs where necessary superjacent to a
● No further motion commands are possible in the BCS during synchronization.
● Motion commands in the OCS are only possible once the status SYNCHRONIZED has
The desired position of the product in the OCS can be approached after the synchronization
via a path command in the OCS.
The following applies for the synchronization mode ON_POSITION:
The synchronization process will be aborted when the direction of the encoder value
reverses during the synchronization.
This can occur when the external encoder of a conveyor belt delivers a fluctuating position
value during standstill due to missing filters or an insufficient tolerance window (with
Extrapolation) which results in a direction reversal of the acutal position.
Synchronization status
The synchronization status of the kinematic end point to a coupled OCS is indicated in the
ocs[i].trackingState system variables on the OCS.
The synchronization status is SYNCHRONIZED when
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The following synchronization modes are available:
– Other coupling with the position in the OCS specified in the command
(setting: synchronizingMode:=IMMEDIATELY)
Synchronization is executed immediately and coupled with the OCS.
– Synchronization and coupling in the OCS at the position of the OCS specified in the
command, i.e. as soon as the ocsTrackingPosition (e.g. of a conveyor belt) has
reached a specified value (the synchronization position) (setting:
synchronizingMode:=ON_POSITION).
For this synchronization mode, a preliminary synchronization is made to the specified
synchronization position in the OCS.
The specification of a motion sequence value, above which travel synchronous with the
OCS is to take place. This value is used only for synchronizingMode:=ON_POSITION.
motion that is still active in the BCS.
been reached.
TO Path Interpolation
Function Manual, 11/2010