Instruction Manual PSE2xxC
21
deceleration decreases during the approach to the destination successively in order
to realize a harmonic transient behavior.
b) Response of drive in case of block or manual displacement
If during a run due to load the speed falls below the threshold parameter of 30% of
the selected maximum speed (SDO #201A) for longer than 200 msec (SDO #201B),
the device detects blockin
g, aborts the run and sets the ‘positioning error’ bit (here the
default values are given).
New run commands can then be transmitted with no further steps to take. An
exception is, if the run should go to the same target than before. In this case,
deassert the release (bit 4 of the control word) and assert it again, then transfer the
target position one more time (either by PDO or SDO).
If the PSE2xxC is displaced by external force during standstill opposite to the loop
direction and the release bit (bit 4) as well as the release readjustment bit (bit 10) in
the control word are still set, the device will attempt to reach the previously
transmitted target value once again (readjustment). The device does not attempt to
readjust if rotated in the loop direction; it merely sets the ‘manual rotation’ bit. If bit 6
(“run without loop”) is set, the drive readjusts the position in both directions.
Deasserting the release bit and/or the release readjustment bit can completely stop
the readjustment process.
c) Internal measuring system
(applys for “singleturn” variants)
The singleturn variants of the PSE2xxC actuator include a partial absolute measuring
system. This means that the position within one turn is measured absolute und the
turns are counted.
These ‘counted turns’ are stored in internal flash every time a run has been finished
or if the actual position value changes during standstill. The value is available after
power up without further commands.
There are two cases that cause the counted turns to be invalid:
1) The output shaft is externally displaced during control power off for more than 36°.
2) Control power is turned off while the PSE2xxC is turning.
In these cases SDO #202A has value 0 (
“actual position is not consistent”).
Now there are three possible ways to continue depending on the amount of
displacement during control power off:
1) No special actions have to be taken if the displacement has been less than 180°
(½ turn): The actual position value is still correct.
2) If the displacement has been more than 180° (½ turn), the correct actual position
value has to be sent to the PSE2xxC (by writing to SDO #2003).
3) First move to a reference position, then write the actual position value with SDO
#2003 (if the displacement has been more than ½ turn and the actual position is
not available otherwise).
The removal of the
motor
power supply has no affect on the internal
measuring system.
