Danfoss VLT5000 SyncPos Operating Instructions Manual page 154

■ ■ ■ ■ ■ SYNCP
The SYNCP command completes an angle/
position synchronization with the master. In doing
so the position according to the gear factors to the
master is kept synchronous, that means after an
external disturbance the program subsequently tries
to recover the corresponding stretch. However, in
doing so the values set for velocity, VEL, and
acceleration, ACC or DEC are not exceeded.
The following parameters affect the behavior:
SYNCFACTM (49), SYNCFACTS (50)
SYNCPOSOFFS (54)
SYNCACCURACY (55)
REVERS (63)
During synchronization the program proceeds as
follows:
When the SYNCP command is started, the actual
master position is determined and is retained.
From the master velocity, and in consideration of the
acceleration allowed, the necessary slave velocity is
calculated in order to reach the master position. The
slave is accelerated so long until the calculated
position has been reached or until it is close enough
to the reference position to reach it.
V
Master Velocity
Slave Velocity
Synchronization command
MG.10.J8.02 – VLT is a registered Danfoss trade mark
gear factors
position offset
accuracy for flag
reverse behavior
t
Programmable SyncPos motion controller
Summary
angle/position synchronization with the master
Syntax
SYNCP
NB!
As soon as the deviation between the position
of the slave and master is less than
SYNCACCURACY (55), the ACCURACY flag is set.
If REVERS (63) is set so that it is not possible to
drive in reverse, but for some reason the slave is
further than the master (e.g. because only the master
has moved in reverse) then the slave will wait at
velocity 0.
In doing so the slave takes its own acceleration time
into consideration and will start moving if necessary
before the correct position has been reached if the
master already has a higher velocity.
Instead of using this catch-up procedure it is also
possible to move the slave with CVEL to approximately
the same velocity as the master and then trigger
SYNCP.
A change in the SYNCPOSOFFS (54) during the
synchronization leads to a new synchronization
procedure with ramps (see above).
NB!
SYNCP should only be called up once since
the synchronizing continues until the next
motion or stop command. All additional SYNCP
commands cause the synchronization to start over
again from the beginning and this is not normally
intended, as you reset the actual SYNCERR.
Command group
SYN
Cross Index
parameter of the AXS group
Syntax-Example
SYNCP
/* normal synchronization of the position */
CVEL 50
/* achieve velocity before synchronization */
CSTART
WAITT 500
SYNCP
153