Functions
09.2008
6SE7087-6QX70 (Version AK)
Siemens AG
7-30
Compendium Motion Control
SIMOVERT MASTERDRIVES
Homing movement REF_TYP = 1
Homing movement is initiated by a rising edge on REF_ON with
homing movement selected by REF_TYP = 1 and the selection of a
preferred direction using D_FWD or D_BWD. If the homing movement
is terminated with REF_STOP and REF_ON is then removed, the
active modes then take effect in their order of priority. REF_TYP is no
longer taken into account. Homing movement is only initiated again with
a rising edge on REF_ON.
Homing movement is initiated by a rising edge on REF_ON and the
preferred direction selected using D_FWD or D_BWD. The reversing
cams REF_STOP_FWD and REF_STOP_BWD reverse the movement
until the homing signal [ARFD] on the input REF_STOP (U866.13)
terminates the movement or the homing enable is removed.
For example, the homing signal is transmitted from a proximity switch to
the interrupt-enabled digital inputs 4 or 5, thus saving the actual
position at the moment the interrupt occurred in the motor encoder
position measurement memory (function diagram 330). The source
position measurement memory enable must be connected (P179 =
891) to the BPos measurement memory enable (function diagram
789c). The position measurement memory enable B0891 is controlled
by the BPos.
The outputs from the position measurement memory pass to the
correction block/homing of the BPos (function diagram 789c).
Actual position at interrupt U877.4 = 122 (position measurement
memory)
Start referencing
U878.3 = 212 (measurement valid)
No correction is performed if the deviation between the reference
position U877.3 and the actual position is less than the innermost
window F1 (U879.1). If the deviation is between F1 and F2 (U879.2),
the position setpoint and actual values are corrected by the deviation. If
the deviation is greater than F2, B0892 is set (print mark outside
window 2).
In the factory setting, binector B0888 (axis referenced) is connected to
the control signal REF_STOP (U866.13, function diagram 789a). If the
input REF_STOP is set, the homing movement is stopped.
The axis then stops on the ramp, which means that it has not reached
the homing position but was stopped ahead of or behind it, depending
on the direction in which it was moving. If required, POS_ON can be
used to carry out an absolute movement (POS_TYP = 1) to this homing
point.
The binector input REF_FWD_STOP restricts the homing movement in
the FWD direction and reverses the direction that was previously
selected using D_FWD and Ref ON (or that is indicated on
REF_STOP_BWD after the reversal).
