Rockwell Automation 8720MC Drives Integration Manual - Manual (Page 53)

Publication 8720MC-IN002A-EN-P — December 2002
Commissioning Your 8720MC Analog Drive 2-21
• Once achieving the “At Program Speed” state, Parameter 330, the
drive will find the marker. After detecting the marker it will change
to positioning mode and determine the desired end point. In this
case it determines it must continue rotating in CCW direction for
another 7500 counts.
• At this time the drive will issue the “Orient Complete” event,
Parameter 583. The motor will be locked in the orient position
until the orient request is removed. As long as the orient request is
maintained the drive will ignore the analog references. As soon as
the orient request is released the drive will follow the analog
references based on the current active mode of operation.
It is possible to orient to a specific angle other than zero as well as
perform multi-revolution orients (refer to parameter 153 “Orient
Angle” in Appendix C).
With the SNS-60 encoder marker orient (8720SM-xxxxxxxS3 and
-xxxxxxxS4 motors), the drive does not know where the marker is
when motor orient is initiated. If the motor is at standstill when the
orient request is received and “Shortest Pth” is selected in Parameter
154 “Orient Options” the drive will assume a clockwise orient
direction. If it is rotating at speed and “Shortest Pth” is selected in
Parameter 154 “Orient Options” it will assume the orient direction is
the same as the direction it is rotating in. If it is rotating at speed and
“CW or CCW” is selected in Parameter 154 “Orient Options” it will
assume the orient direction is as programmed in 154, regardless of the
direction that it is currently rotating in. If the orient direction is
different from the current motor speed direction it will stop and
reverse direction for the orient.
As a final note to the operation of motor orient, the drive will hold the
motor locked in the orient position until the orient request from either
the digital I/O or SCANport is released. If the drive is enabled and
there is a non zero analog reference command on Analog Input 1 in
Auto Mode or Analog Input 2 in Manual Mode the drive will
immediately respond to the input reference and motor will accelerate
to the commanded speed. If this is undesirable make sure the analog
references are zero after an orient is complete.
ATTENTION
!
Unexpected motor rotation may occur after a
spindle orient request is released from the
digital input. If motion is not desired after an
orient request is removed from the drive digital
input make sure your logic assures that zero
speed is commanded or that the drive is
disabled.