Function - Mitsubishi Electric MELSERVO-J4 series Instruction Manual

15. USING A DIRECT DRIVE MOTOR

15.3.4 Function

(1) Servo control error detection function
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 [Pr. PL04
Linear servo motor/DD motor function selection 2]. The detection level can be changed with [Pr. PL05],
[Pr. PL06], and [Pr. PL07].
(a) Position deviation error detection
Set [Pr. PL04] to "_ _ _ 1" to enable the position deviation error detection.
When you compare the model feedback position ( 1)) and the feedback position ( 2)) in figure 15.1, if
the deviation is more than the value of [Pr. PL05 Position deviation error detection level] (1 (0.01 rev)
to 1000 (10 rev)), [AL. 42.1 Servo control error by position deviation] will occur and the linear servo
motor will stop. The initial value of this detection level is 0.09 rev. Replace the set value as required.
POINT
For the servo control error detection function, the position and speed deviation
error detections are enabled by default. ([Pr. PL04]: _ _ _ 3)
Servo amplifier
Servo amplifier internal value
1) Model feedback position [rev]
3) Model feedback speed [r/min]
5) Command torque [%]
Encoder
2) Feedback position [rev]
4) Feedback speed [r/min]
6) Feedback torque [%]
Figure 15.1 Outline of servo control error detection function
[Pr. PL04]
1
Position deviation error detection enabled
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Direct drive motor
Encoder