The DCC board Z-axis overspeed sense circuit has detected a tachometer voltage greater than should be required for normal DCC command velocity. Possible causes are:
Excessive tachometer commutation noise voltage spikes. The servo drive is slipping during acceleration and overspeed during its constant velocity move command to "catch up'' to the commanded position.
The speed sense potentiometer on the DCC board for the Z-axis is set too low.
There is a short circuit in the power output driver of the Z-axis servo amplifier on the servo control unit (SCU) chassis. This causes the full 60V DC power to be sent to the motor.
What you should do:
To clear the error, click Clear error in the XYZ Display window.
To clear it using an RCU-II, press and hold down the Servo Power Off button and then press the Joy button twice.
Make sure that the servo tachometer is operating properly.
Make sure that the drive mechanism is operating properly.
Make sure that the DCC board overspeed sense potentiometer reference voltage is set high enough.
If the error reoccurs, contact your Giddings & Lewis service representative.