User`s manual

13 - 3
13
Though there is no difference in control during regular operation, operation of this module differs
during zero return caused by an emergency stop, for example. So, correspondingly matching
control must be performed.
What is problematic is that a positional shift may occur when the procedure is performed incorrectly
in adjustment of the present position between this module and the servo driver. This is caused by
the shift between the present value counter in this module and the present value counter in the
servo driver, and occurs by control of the servo driver motor power supply. (as the position
information of the axis that moved by external force and inertia when the motor was turned OFF).
You can select whether to hold the present value (origin) when an error occurs or set the origin to
unconfirmed by [designation of origin unconfirmed at hardware error (parameter 1 - 0001- bit 0)],
[emergency stop input function selection (parameter 1 - 0000 - bit 5)] and [designation of origin
unconfirmed at software limit error (parameter 1 - 0001 - bit 1)].
When the previous state is set to "held" (see tables 1 to 3), this module judges that the servo driver
can control the motor at all times. Even if an emergency stop, etc. occurs, the present value is held
on the assumption that this module is positioning at all times to the instructed position by the servo
driver's deviation counter.
When the servo driver is not in a state where the motor can be controlled at all times (when the
servo power supply is OFF as a result of the interlock with emergency stop, etc.), the present value
(origin) must be set to unconfirmed (see tables 1 to 3). This is because the servo driver's deviation
counter is no longer matched with the present value of this module when the servo is recovered.
So, a zero return is required at restartup when there is no compensation operation function
according to the absolute system or encoder feedback.
The following describes the recovery procedure in the configurations (1) to (4) above.
(1) When an incremental type driver is used
When powered ON, this module clears the present value to "0" (zero). Also, when a zero return is
performed, the position where zero return ends becomes "0". When an error (emergency stop,
etc.) occurs and the servo is turned OFF, perform zero return by the following procedure:
Clear the error.
Clear deviation.
Turn the servo ON.
Turn the servo ON.
13-2 Cautions in system configuration with servo driver
Parameter setting
Method of use
Closed loop control
mode selection
parameter 2
address 0000
Absolute value control
mode selection
parameter 2
address 0020
When an incremental type driver is used
When an absolute system-compatible driver is used
When an incremental type driver and encoder
feedback are used
When an absolute system-compatible driver and
encoder feedback are used
(1)
(2)
(3)
(4)
0, 1
2
0, 1
2
Unused (0)
Unused (0)
Used (1)
Used (1)
There are four ways to configure this module and the servo.