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3. SIGNALS AND WIRING
3 - 58
3.7.3 Vertical axis freefall prevention function
The vertical axis freefall prevention function avoids machine damage by pulling up the shaft slightly like the
following case.
When the servo motor is used for operating vertical axis, the servo motor electromagnetic brake and the
base circuit shut-off delay time function avoid dropping axis at forced stop. However, those functions may
not avoid dropping axis a few
μ
m due to the backlash of the servo motor electromagnetic brake.
The vertical axis freefall prevention function is enabled with the following conditions.
Other than "0" is set to [Pr. PC54 Vertical axis freefall prevention compensation amount].
The servo motor speed decelerates lower than the value of zero speed by turning off EM2 (Forced stop
2) or by an alarm occurrence.
The base circuit shut-off delay time function is enabled.
EM2 (Forced stop 2) turned off or an alarm occurred while the servo motor speed is zero speed or less.
(1) Timing chart
MBR
(Electromagnetic
brake interlock)
ON
OFF (Enabled)
Base circuit
(Energy supply to
the servo motor)
ON
OFF
Actual operation of
electromagnetic brake
Disabled
Enabled
Position
Travel distance
ON
OFF (Enabled)
EM2 (Forced stop 2)
Set the base circuit shut-off delay time. ([Pr. PC16])
(2) Adjustment
Set the freefall prevention compensation amount in [Pr. PC54].
While the servo motor is stopped, turn off the EM2 (Forced stop 2). Adjust the base circuit shut-off
delay time in [Pr. PC16] in accordance with the travel distance ([Pr. PC54). Adjust it considering the
freefall prevention compensation amount by checking the servo motor speed, torque ripple, etc.
3.7.4 Residual risks of the forced stop function (EM2)
(1) The forced stop function is not available for alarms that activate the dynamic brake when the alarms
occur.
(2) When an alarm that activates the dynamic brake during forced stop deceleration occurs, the braking
distance until the servo motor stops will be longer than that of normal forced stop deceleration without
the dynamic brake.
(3) If STO is turned off during forced stop deceleration, [AL. 63 STO timing error] will occur.
Summary of Contents for MR-J4-100A(-RJ)
Page 19: ...10 MEMO ...
Page 75: ...1 FUNCTIONS AND CONFIGURATION 1 56 MEMO ...
Page 83: ...2 INSTALLATION 2 8 MEMO ...
Page 159: ...3 SIGNALS AND WIRING 3 76 MEMO ...
Page 203: ...4 STARTUP 4 44 MEMO ...
Page 351: ...7 SPECIAL ADJUSTMENT FUNCTIONS 7 40 MEMO ...
Page 365: ...8 TROUBLESHOOTING 8 14 MEMO ...
Page 387: ...9 DIMENSIONS 9 22 MEMO ...
Page 403: ...10 CHARACTERISTICS 10 16 MEMO ...
Page 553: ...12 ABSOLUTE POSITION DETECTION SYSTEM 12 30 MEMO ...
Page 567: ...13 USING STO FUNCTION 13 14 MEMO ...
Page 607: ...14 COMMUNICATION FUNCTION MITSUBISHI ELECTRIC GENERAL PURPOSE AC SERVO PROTOCOL 14 40 MEMO ...
Page 639: ...15 USING A LINEAR SERVO MOTOR 15 32 MEMO ...
Page 767: ...18 MR J4 03A6 RJ SERVO AMPLIFIER 18 84 MEMO ...
Page 856: ...APPENDIX App 41 ...
Page 905: ...MEMO ...