Omron R88D-UA Manual page 35

Servo Driver Errors
Note 1. In many cases, signal cable errors will be detected together with encoder or resolver discon-
nection errors.
Note 2. If the cable contact is improper, the resistance of the cable will vary slightly. To check a slight
difference in resistance in such a case, use a multimeter that has a mΩ range.
Encoder (Resolver) Disconnection
• An alarm will go off if there is no encoder or resolver voltage output.
Alarm Indication
U Series: A. C3, A. C4
H Series: E1
M Series: A. L-6
R Series: RE. E
Probable cause
Abnormal encoder signal lines.
Abnormal resolver signal lines.
Motor overheating.
Encoder or resolver malfunctions.
Signal errors caused by noise.
Note 1. In many cases, signal cable errors will be detected together with encoder or resolver discon-
nection errors.
Note 2. If the cable contact is improper, the resistance of the cable will vary slightly. To check a slight
difference in resistance in such a case, use a multimeter that has a mΩ range.
Item to check
• The signal lines are discon-
nected.
• The signal lines are short-cir-
cuited.
* Check the resistance of the
cable alone.
• The surface temperature of the
encoder exceeds 70°C. (Applica-
ble to H and R Series only.)
• Do not turn any output signal of
the encoder on and off if the volt-
age of the output signal between
the output terminal and the pow-
er supply ground of the encoder
is 2.5 V min.
• The resistance between each
combination of these terminals
of the resolver is far from the
rated resistance.
SIN energized terminals:
100 Ω
COS energized terminals:
110 Ω
Resolver output terminals:
5,000 Ω
• None of the above items applies.
• The frequency and conditions of
error are indefinite.
Chapter 3
Countermeasure
• Replace the encoder cable.
• Replace the resolver cable.
• Decrease the motor ambient
temperature.
• Take the same countermeasures
as those against motor overload.
• Replace the motor.
Take countermeasures against
noise. Refer to Chapter 4
Countermeasures Against Noise.
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