Servo On/Off; Follow-Up Function - Mitsubishi FX3U-20SSC-H User Manual

FX -20SSC-H Positioning Block User's Manual
3U
3. Absolute position lost
If the absolute position in the encoder becomes indefinite in the absolute position detection system, the
absolute position loss signal (ABSV) turns ON. At ABSV signal ON, make sure to operate zero return
immediately to establish the zero-point again.
The absolute position becomes indefinite in the three cases below.
• When changed into the absolute position detection system by the parameter setting of the servo amplifier,
and the servo amplifier turns ON.
• An absolute position loss alarm (AL-25) is caused.
• An absolute position counter warning (AL-E3) is issued.
Note
While the absolute position loss signal (ABSV) is ON, do not start the automatic operation. Otherwise the
system will run away.
7.6.5

Servo ON/OFF

The servo of the servo amplifier connected with 20SSC-H turns ON/OFF.
The servo ON enables the servomotor operations.
1. Servo ON/OFF
• Turn OFF(0) the servo-OFF command to turn the servo on.
• Turn ON (1) the servo-OFF command to turn the servo off.
Note
• Perform servo-ON/OFF while the servomotor is stopped.
• The servo can be turned OFF with Ready-ON in the status information.
The servo-OFF command during positioning operation is invalid.
• If the servomotor turns due to an external force during servo-OFF, a follow-up process occurs with the

follow-up function.

7.6.6 Follow-up function
With the follow-up function, the motor rpm is monitored when the servo is OFF, and the motor rpm is reflected
in the current value.
With this function, even if the servomotor rotates while the servo is OFF, the servomotor always starts
positioning at the next servo-ON, ignoring the drop pulse.
The 20SSC-H always executes the follow-up process during servo OFF.
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→ For related parameters, control data and monitor data, refer to Section 7.9
→ For related parameters, control data and monitor data, refer to Section 7.9
7 Before Starting Positioning Operation
7.6 Other functions