Gear Generator And Reference Handling - Danfoss iC7 Motion Series Application Manual

Application Guide | iC7 Series Motion
When marker synchronizing is selected, the Start Synchronizing signal starts the Relative Sync mode, and the follower position is locked
to the master position until the first pair of markers is found. At this point, the first alignment of the markers is done. The first marker
alignment is done by the follower catching up or slowing down depending on the selected behavior. When synchronizing to a running
master, the follower first catches up with the master. When the follower is in sync, marker correction commences with the first pair of
markers.
The 3 start behaviors are illustrated in the following picture:
Start Synchronizing
Master
1 2
Follower
1 2
Master
1 2
Follower
1 2
Master
1 2
Follower
1 2
Figure 15: Marker Synchronizing Behaviors
Offset Adjustment
The offset between master and follower can be adjusted by using superimposed movement. Superimposed movement displaces the
follower relative to the master by an absolute or a relative positioning, on top of the ongoing synchronization. If marker synchronizing is
selected, the superimposed movement offsets the alignment of the markers.

Gear Generator and Reference Handling

2.12.3.3
The reference for gear mode is selected with parameter 5.16.2.1 Master Source Selection. The parameter has selections device 1 and
device 2, if Encoder/Resolver Option OC7M0 is installed. An overview of supported devices can be found in the iC7 Series Functional
Extension Options Operating Guide.
The reference or master signal is converted to follower position units by the gear ratio, which is set with parameters 5.15.3.2 Gear Ratio
Numerator and 5.15.3.3 Gear Ratio Denominator. The actual master position readout in parameter 5.16.1.1 Master Position is thus in
follower position units.
Based on the master position and the selected synchronizing mode and start behavior, the gear generator calculates demanded values
for position, speed, and acceleration. Those values are used as references for the position and speed controllers.
In marker synchronizing, the superimposed profile generator is adding to the demanded values, modifying the master – follower
offset to align the markers. For marker correction, the follower speed is limited relative to the master speed with +/- the value set with
parameter 5.15.3.4 Superimposed Speed Difference.
The following image shows an overview of the synchronizing references.
© 2023.11
Marker Sync
3 4
3 4
Marker Catch Up
3 4
3 4
Marker Slow Down
3 4
3 4
5
5
Time
5
5
Time
5
5 Time
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