1136

Common Causes

• Failed DD encoder / absolute position sensor
• Encoder gap out of tolerance (too narrow or too wide)
• Encoder head inclination misaligned
• Communication error between the encoder and the control

Troubleshooting Steps

1. 1Read the code number shown with the alarm: code XX bit7 = Error bit; 1 indicates an error condition; code XX bit6 = Absolute position sensor margin warning; code XX bit5 = Gap warning; steady 1 = gap too small, toggling = gap too large; code XX bit4 = Inclination warning; steady 1 = CCW too large, toggling = CW too large; code XX bit3 = Auto set mode active; code XX bit2 = Communication error detected; code XX bit1,0 = Error bit number of the absolute position code; code YY=01 = Stop command has stopped
2. 2Read the XXYYZZZZ code on screen. Check the YY alarm code first: 42 means the encoder gap is too narrow, 43 too wide, 40/41 an inclination error in the plus/minus direction, 02 a control parameter error, 05 initialization speed too high, 0D speed too high, 0E a synchronization error, 04/20 an absolutization problem, and 3E/3F absolute position sensor or code errors.
3. 3Also read the XX status byte: bit6 flags an absolute position sensor margin warning, bit5 a gap warning, bit4 an inclination warning, and bit2 a communication error, which tells you whether the problem is mechanical alignment or the signal path.
4. 4For gap (42/43) or inclination (40/41) codes, power down and lock out, then inspect and re-set the DD encoder head mounting gap and tilt to specification; clean the scale/reading surface of coolant or chips.
5. 5For communication or sensor error codes (bit2, 3E, 3F, 21), inspect the encoder cable and connectors for damage or poor seating before condemning the encoder.
6. 6If alignment and cabling are correct and the alarm persists, replace the DD encoder, which is the manual's listed faulty location.
7. 7If it returns after these checks, record the alarm number, code and object and contact Okuma service.