Fuji Electric ALPHA7, User Manual

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CHAPTER 7 MAINTENANCE AND INSPECTION
7-12
Troubleshooting Method
7
8. Encoder Communication Error
[Display] [Description of detected alarm]
AL.Ec -
Communications with the internal encoder of the servomotor fails.
[Cause and remedy]
Cause Remedy
Interrupted encoder
communications

Check cables visually and through continuity check and
correct faults.

Check for the broken wire in the encoder cable and correct.

Insert ferrite cores.
Broken wire or poor contact
The servo amplifier and encoder communicate through high speed serial communications.
The encoder cable has a voltage amplitude of about +5 [V]. Do not route the encoder cable in a
strong magnetic or electric field. Route the encoder cable separately from the main body of the
servo amplifier, inverter, electromagnetic contactor or similar (reserve at least 100 [mm]).
9. CONT (control signal) Error
[Display] [Description of detected alarm]
AL.ctE
There is duplication in allocation of sequence input terminals of the
servo amplifier.
[Cause and remedy]
Cause Remedy
The same input signal is allocated to two or
more terminals.

Do not specify the same number among
CONT signal settings.