Rockwell Automation 8720MC Drives Integration Manual - Manual (Page 148)

Publication 8720MC-IN002A-EN-P — December 2002
C-36 Programming Parameters
Name: Spin_Orient_Req Data Display: Bit Pattern R/W
Parameter No.
152
File:
Procedure
Group:
Orient Description: Spindle Orient Procedure Command. This procedure command automatically switches the drive to
internal position loop control, below the spindle orient speed (parameter 222), and initiates an orient to the defined
orient position. In a SERCOS drive when bits 0 and 1 of parameter 152 are set true an orient is requested. Orient
is also requested when input 2 is set true at the digital interface. While the orient procedure is active, all changes
to external velocity, position or torque command values are ignored.
If the drive is stopped an orient procedure command initiates a clockwise, counter-clockwise or shortest
path orient depending on the spindle Orient Options, Parameter 154 (parameter 154). The drive positions the
spindle to the programmed orient angle, parameter 153 (parameter 153), using the spindle orient speed specified
in parameter 222 and the position acceleration rate defined in parameter 260. The actual target position is derived
from the motor or spindle mounted encoder as determined by it’s zero reference marker in the case of an
incremental encoder or it’s absolute zero position in the case of a single turn absolute encoder. For motor
mounted feedback the target position is calculated by the 8720MC as encoder zero - parameter 150 + parameter
153. For spindle mounted feedback in the SERCOS configuration the final position is calculated by the 8720MC as
encoder zero ± parameter 151 ± parameter 153. When the drive interpolator reaches the selected orient position,
the drive sets the status “Orient Complete”, parameter 583. The status “In Position” (parameter 336) is true as
long as the drive is in the orient position and the spindle position is within the in- position band established by
parameter 57, “IN_Pos_Value”.
If the drive is rotating at a speed higher than the orient speed when the orient request is received the drive
will decelerate at the acceleration rate defined in parameter 260 to the orient speed defined in parameter 222. If
parameter 154 calls for clockwise orient and the drive is already rotating clockwise and the drive has decelerated
to orient speed, the drive will place itself in positioning mode and decelerate to the calculated target orient angle
moving in the clockwise direction. If parameter 154 calls for counter-clockwise orient and the drive is already
rotating clockwise and the drive has decelerated to orient speed the drive will place itself in positioning mode and
decelerate to a stop. It will then move to the calculated target orient angle moving in the counter-clockwise
direction. If parameter 154 calls for shortest path orient and the drive is already rotating clockwise or
counter-clockwise once the drive decelerates to orient speed the drive will place itself in positioning mode and
decelerate to the calculated target orient angle moving in the same direction as the spindle was rotating when the
orient request occurred. For motor mounted feedback the target position is calculated by the 8720MC as encoder
zero - parameter 150 + parameter 153. For spindle mounted feedback in the SERCOS configuration the final
position is calculated by the 8720MC as encoder zero ± parameter 151 ± parameter 153. Since it is being
subtracted a - value in parameter 151 produces a clockwise offset angle when facing the shaft end of the motor
or the drive end of the spindle and a + value in parameter 151 produces a counter-clockwise offset.
The drive will remain oriented in servo position lock as long as the spindle orient request input is enabled.
When the orient request is removed the drive switches over to the mode of operation called for in the mode
parameter of the active parameter set. The drive will immediately follow the auto reference if auto mode is active.
Default:
null Length
2 bytes Minimum/Maximum
N/A Scaling Resolution
N/A Units
N/A