YASKAWA SGD7S-1R9D Product Manual page 509

Alarm Code:
Possible Cause
Alarm Name
The parameter set-
tings are not correct.
There is noise on the
scale signal.
C50 hex:
Polarity Detec-
tion Failure
An external force was
applied to the Moving
Coil of the motor.
C50 hex:
The linear encoder
Polarity Detec-
resolution is too low.
tion Failure
Confirmation
The settings of Pn282
(2282 hex) (Linear
Check the linear Encoder Pitch) and Pn080
encoder specifications (2080 hex) = n.X
and feedback signal (Motor Phase Selection)
status. may not match the instal-
lation. Set the parame-
ters to correct values.
Check to make sure
that the frame grounds
of the Serial Converter
Unit and Servomotor
are connected to the
FG terminal on the SER-
VOPACK and that the
FG terminal on the SER- Implement appropriate
VOPACK is connected countermeasures against
to the frame ground on noise for the Linear
the power supply. Encoder Cable.
And, confirm that the
shield is properly pro-
cessed on the Linear
Encoder Cable. Check
to see if the detection
reference is repeatedly
output in one direction.
The polarity cannot be
properly detected if the
detection reference is 0
and the speed feedback
is not 0 because of an
external force, such as
cable tension, applied to
the Moving Coil. Imple-
– ment measures to reduce
the external force so that
the speed feedback goes
to 0. If the external force
cannot be reduced,
increase the setting of
Pn481 (2481 hex) (Polarity
Detection Speed Loop
Gain).
If the linear encoder scale
pitch is 100 μm or higher,
the SERVOPACK cannot
detect the correct speed
feedback. Use a linear
encoder scale pitch with
higher resolution. (We rec-
Check the linear ommend a pitch of 40 μm
encoder scale pitch to or less.) Or, increase the
see if it is within 100 setting of Pn485 (2485
μm.
hex) (Polarity Detection
Reference Speed). How-
ever, increasing the set-
ting of Pn485 (2485 hex)
will increase the Servomo-
tor movement range that
is required for polarity
detection.
15.2 Alarm Displays
15.2.2 Troubleshooting Alarms
Continued from previous page.
Correction Reference
page 5-15,
page 5-20
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–
–
Continued on next page.
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