NSK EDD Megatorque Motor - Alarm A4: Excess Velocity; Warning A5: Home Position Undefined

11. Alarm and Warning
— 11-11 —
11.3.6. Alarm A4: Excess Velocity
 This alarm detects that the Motor has continuously rotated faster than the velocity of 11.4 [s
-1
] for 10
milliseconds or over, exceeding its maximum rotational speed 10 [s
-1
].
Table 11-13: Cause and remedy for the alarm P4
Cause
Remedy
(1)
Unmatched combination of Motor
and Driver Unit.
 Check for proper combination
(2)
Motor velocity has exceeded the limit
due to external disturbance.
 Check for cause of the external disturbance.
(3)
Velocity has reached the limit due to
overshooting.
 Refer to “5. Tuning”.
 Reduce the parameter settings of acceleration and deceleration.
(4)
Defective cable, Motor or Driver Unit.
 Follow “Appendix 2: How to Check Motor Condition” for checking their
conditions. Replace the cable or the Motor if necessary.
 If above procedures do not work, the Driver Unit nay be defective. Replace
it referring to “Appendix 5: Procedure for Replacing Driver Unit Model
EDD.”
(1) The maximum rotational speed setting of parameters such as the parameter MV is 10 [s
-1
]. However the
maximum rotational speed depends on each Motor model. Refer to “2.5. Motor Specifications” and set
the operating velocity not to exceed the specification.
11.3.7. Warning A5: Home Position Undefined
 In case of absolute positioning operation, the Driver Unit specifies the target position in accordance with
the preset home position.
This warning occurs when the command for absolute positioning operation is inputted even the home
position is not yet defined.
 The state of undefined home position occurs when the Home Return operation is interrupted
even the command has been executed.
Table 11-14: Cause and remedy for the warning A5
Cause
Remedy
(1)
The command for absolute positioning
operation is inputted after an interruption
of Home Return operation.
 Complete the Home Return operation.
(1) The input ACLR or the command CL clears the warning.