Yaskawa YASNAC PC NC Maintenance Manual - Manual (Page 82)

Chapter 4: Troubleshooting PC NC Maintenance Manual
4-61
Cause and measures
AL-64:Position detection signal disconnection
Error Contents Encoder signal conductor disconnection / improper connection for the
position detection (encoder method ORT)
Detection Methods If the following condition consists, an alarms will sound. (encoder
method ORT card is installed) / (encoder selection is set of load axis
encoder [C1-22.b6 = 0) / (ORT card encoder disconnection signal is
ON).
Cause and measures
Cause Measures
Motor and inverter earth is defective. Check continuity to see that the motor and inverter are properly
grounded.
Improper drive by noise (encoder cable
characteristic defect) Check the encoder signal conductor is isolated from the main circuit
wiring and other power lines.
Check encoder cable specification (twisted-pair shield wire) [recom-
mended cable “KQVV-SW” by Fujikura-Densen Co.]
Load axis encoder fault Confirm A, B, and the C-phase pulse by the check terminal on the ori-
entation card.
Exchange the load axis encoder with a non-defective one.
Control card fault Exchange unit (exchange control card)
Cause Measures
Load axis encoder signal conductor
disconnection, improper connection,
and connector omission Check load axis encoder signal conductor wiring.
Load axis encoder fault Exchange the load axis encoder with a non-defective one.
Orientation card fault Confirm the A, B, and the C-phase pulse by the check ter-
minal on the orientation card.
Exchange the orientation card with a non-defective one.
Exchange the load axis encoder with a non-defective one.