7 ABSOLUTE POSITION DETECTION SYSTEM
7.3 Absolute position detection system by DIO [A]
307
7
■
During forced stop release
• When power is switched on in a forced stop status
Even if forced stop is canceled during absolute position data transfer, there is no problem with the transfer. If forced stop is
canceled during the absolute position data transfer, the base circuit turns on 200 ms to 450 ms after the cancellation. If ABSM
is off, RD is turned on 5 ms after the base circuit turns on. If ABSM is on, RES is turned on after ABSM is turned off. ABS
transfer can be done even after forced stop cancellation.
The current position in the servo amplifier is updated even during a forced stop. As shown in the following diagram, when
SON or ABSM is turned on at forced stop, at the timing of when ABSM switches from off to on, the servo amplifier
simultaneously send the latched current position to the controller side, and the servo amplifier sets this data as the position
command value. However, since the base circuit is off during a forced stop, the status does not switch to servo-lock.
Therefore, if the servo motor is rotated by external force or the like after ABSM is turned on, this travel distance is
accumulated in the servo amplifier as droop pulses. If the forced stop is canceled at this status, the base circuit turns on and
returns to the original position rapidly to compensate for the droop pulses. To avoid this status, read the absolute position data
again before canceling the forced stop.
OFF
ON
OFF
ON
OFF
ON
OFF
ON
OFF
ON
OFF
ON
OFF
ON
5 ms
OFF
ON
Power supply
SON (Servo-on)
Released
EM2 (Forced stop 2)
ABSM (ABS transfer mode)
During ABS transfer
ABSR (ABS request)
ABST (ABS transmission data ready)
ABSB0 (ABS transmission data bit 0)
ABSB1 (ABS transmission data bit 1)
Absolute position
data
200 to 450 ms
Base circuit
RD (Ready)
Operation possible
Summary of Contents for MELSERVO-J5 MR-J5-G Series
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