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Synchronizing controller
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MG.10.N4.02 - VLT is a registered Danfoss trademark
Then use the following procedure:
5. Close the contacts at terminal 32 (clockwise direction) or terminal 33 (counter-clockwise). During
the test the last value of the first displa
y
line will indicate the track error (PID error). After the test
run is completed you can see the maximum track error (PID error).
6. Increase the P-portion (par. 702). After each change you should make a test run to find the right
setting. If the drive becomes unsteady or if a message is given about over-voltage or over-
current, then reduce the value in parameter 702 to about 70-80% of the set value.
7. Now set the D-portion (parameter 703) to 5 times the value of parameter 702.
8. If a lower synchronizing error is required the I-portion (parameter 704) can be set to a low
value e.g. 10 but be careful a too high value will course overshoot and instability
For test run with virtual master the following parameters must be set:
Parameter 748 Virtual master reference: Select the reference source for setting the velocity
of the virtual master. “0” is analogue input 53, “1” is analogue input 60, “2”
is parameter 216 and “3” is Field bus PCD 2.
Parameter 749 Virtual master acceleration: Set the acceleration of the virtual master in
encoder pulses per second
2
.
Parameter 750 Virtual master maximum speed: Set the maximum velocity of the virtual
master in encoder pulses per second.
Then use the following procedure:
1. Start test run with virtual master by activating input 3. During test run you can read the
track error in the last value of the first display line. At stop the maximum track error
during the test run is read out. Because velocity synchronization is selected (parameter
728 = 0) the track error is velocity deviance between master and slave.
2. If more accurate and dynamic control is required the P-portion (parameter 702) must be
increased. If the slave becomes unstable the value must be reduced to by approximately
25%.
3. Now set the D-portion (parameter 703) to 5 times the value of parameter 702
4. If a lower synchronizing error is required the I-portion (parameter 704) can be set to a
low value e.g. 10 but be careful a too high value will course overshoot and instability.
If the interval between two marker signals at the slave is not known, this interval can now be
measured. To do this, the contact at the Slave marker search input (I8) is closed. The slave
drive now rotates at the set test run speed. With each master signal, the interval can be read off
in Parameter 722. If the marker search is stopped by opening the Slave marker search contact
(I8), an average of all the marker intervals is taken, and this is entered as the value in Parameter
722. Similarly, the intervals between the marker signals of the master drive are measured by
means of the Master marker search input (I7). To do this, it is necessary to start the master. The
intervals are continuously displayed in Parameter 724. After opening the Master marker search
contact (I7), the calculated average of all the measurements is again entered as the final result
in Parameter 724.
After the drive has been optimized, the data found are stored by activating Input I4 (Store), or by
changing Parameter 710 to “1”.