Synchronizing controller
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MG.10.N4.02 - VLT is a registered Danfoss trademark
Description of Field bus interface
NOTE: This section is only relevant if the VLT is equipped with a Field bus interface (option) as well as
the Synchronizing controller.
The Synchronizing controller can be controlled via the digital/analogue inputs or via field bus. The
control source can be selected individually for test-run and synchronizing in the parameters 753 (test-
run) and 754 (synchronizing). There can only be one control source at a time meaning that the
digital/analogue inputs are inactive when Field bus is selected as control source and visa versa. The
only exception is input 27, which is always stop/enable also when Field bus is selected as control
source. In synchronizing mode three signals are only available as digital inputs even when Field bus is
selected as control source that is the marker signals for marker synchronization and the Home switch.
This is because these signals are too time-critical for Field bus control.
Status signals are always available on the digital/analogue outputs but they are only available via Field
bus when Field bus is selected as control source.
Data layout
Control and status signals are transferred via the so-called process data channel (PCD) of the various
field bus interfaces. The telegram structure and the available number of data words depends on the
Field bus used, please refer to the manual of the Field bus option in use for further details. The below
example is based on the layout of a PROFIBUS telegram, the so-called PPO:
Example using PROFIBUS PPO type 5:
Field bus control signals:
Field bus
[word.bit]
Test run
Synchronizing
Corresponding input
1.1
Not used
Start of synchronization
1
1.2
Not used
Take over gear ratio
2
1.3
Start/stop virtual master
Start/stop virtual master
3
1.4
Save settings
Save settings
4
1.5
Not used
VLT-mode 8
1.6
Not used
Gear-ratio select MSB
16
1.7
Not used
Gear-ratio select LSB
17
1.8
Not used
Start homing
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