Mitsubishi Electric MELSERVO-J3W Series, Instruction Manual

Page: 358 / 500

14. USING A DIRECT DRIVE MOTOR
14 - 25
14.4.4 Function
(1) Servo control error detection function
POINT
For the servo control error detection function, the position and speed deviation error
detections are enabled by default. (parameter No.PS04: 3)
If the servo control gets unstable for some reasons, the direct drive motor may not operate properly. To
detect this state and to stop operation, the servo control error detection function is used as a protective
function.
The servo control error detection function has three different detection methods: the position deviation,
speed deviation, and torque deviation. An error is detected when each method is enabled with parameter
No.PS04 (Special function selection 4). The detection level can be changed with parameter Nos.PS05,
PS06 and PS07.
Direct drive motor
Encoder
Servo amplifier internal value
1) Model feedback position [rev]
3) Model feedback rotation speed [r/min]
5) Command torque [ ]
Encoder
2) Feedback position [rev]
4) Feedback rotation speed [r/min]
6) Feedback torque [ ]
Servo amplifier
Figure 14.1 Outline of servo control error detection function
(a) Position deviation error detection
Set parameter No.PS04 to " 1" to enable the position deviation error detection.
Position deviation
error detection valid
1
Parameter No.PS04
When you compare the model feedback position ( 1)) and the feedback position ( 2)) in figure 14.1, if
the deviation is more than the value of parameter No.PS05 (Servo control position deviation error
detection level) (1 rev to 1000 rev), the alarm (Servo control error 42. ) will occur and the motor will
stop. The default value of parameter No.PS05 is 0.09rev. Change the set value as required.