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Protective Functions
Protection
* Encoder A/B-
phase
error
*
Encoder
communication
error
* Encoder
connection
error
*
Encoder
communication
data error
Position
error
Hybrid
error
Over-speed
Alarm
Code No.
20
21
22
23
24
25
26
Cause
No A- and B-phase pulse is detected. The 11-
wire encoder failed.
Due to no communication between the encoder
and driver, the detective function for broken en-
coder wires is activated.
The connection between the 11-wire encoder
and driver is broken. The encoder rotates higher
than the specified rate when control power is on
.
The encoder sends an erroneous data mainly
due to noises. The encoder is connected cor-
rectly, though the data is not correct.
The position error pulse is larger than Pr63 (po-
sition error limit). The motor operation does not
respond to the commands.
When the driver of the full-closed version is un-
der the full-closed and hybrid control with an
external encoder, the load position detected by
the external encoder and the motor position
detected by the motor encoder are beyond the
limit specified by Pr73 (hybrid error limit).
The motor velocity exceeds the specified limit.
Countermeasures
Correct the encoder wiring per the wiring dia-
gram. Correct the connection of the pins.
Make sure that the power of the encoder is 5VDC
? 5% (4.75 to 5.25V). Especially when the wire
length is long, it is important to meet this require-
ment. You should not bundle the encoder wires
and motor wires together. Connect the shield to
FG. See the encoder wiring diagram.
Check whether the motor operates per the po-
sition command pulse or not. See the torque
monitor to check if the output torque is saturated.
Readjust the gains. Maximize the value of Pr5E
(torque limit set-up). Correct the encoder wiring
per the wiring diagram. Increase the accelera-
tion and deceleration time. Reduce the load and
velocity.
Check the connection between the motor and
load. Check the connection between the exter-
nal encoder and driver. Correct the values of the
external scale numerator and denominator re-
garding parameters Pr74, Pr75, Pr 76 and Pr77.
Increase the value of Pr73. Increase the value
of Pr71 (hybrid switching time).
Decrease the target speed (command values).
Decrease the value of Pr50 (velocity command
input gain). Adjust the scale ratio so that the fre-
quency of the command pulse is 500 kpps or
less. If an overshoot occurs, readjust the gains.
Correct the encoder wiring per the wiring
diagram.ÅB
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