4136

Common Causes

• DD encoder failure or internal absolute-position sensor fault
• Encoder gap too small or too large after mechanical disturbance
• Encoder head inclination or runout outside the readable range
• Communication problem between the DD encoder and the MCS hardware

Troubleshooting Steps

1. 1Read the code number shown with the alarm: code XX bit7 = Master error flag; when set, decode YY as the active fault; code XX bit6 = Absolute position sensor is near its limit; warning rather than normal; code XX bit5 = Gap warning; steady means gap too small, toggling means gap too large; code XX bit4 = Inclination warning; steady means CCW side is large, toggling means CW side is large; code XX bit3 = Encoder is in auto-set mode instead of normal mode; code XX bit2 = Communication error is being detected; toggles as it occurs; code XX bits1-0 = Two-bit number for the absolute position code error; code YY=01 = A stop command has stopped the encoder sequence
2. 2Record the object and full XXYYZZZZ code before cycling power; confirm whether the failing item is an axis or the spindle and remember this applies to ICB-H.
3. 3Read XX first: if bit7 is set, use YY to branch; bit6 or bit5 warnings point to marginal absolute position or gap problems rather than a dead encoder.
4. 4For YY 42 or 43, inspect the DD encoder mounting and measure the head-to-scale gap with the machine maker's gauge method; look for a shifted bracket, loose screws, or recent crash damage.
5. 5For YY 40 or 41, check encoder head alignment, shaft runout, and coupling condition; correct mechanical tilt before replacing parts.
6. 6For YY 01, 04, 08, 20, 21, 3E, or 3F, isolate the encoder and its link: lock out and discharge the drive, reseat the encoder connector, inspect the cable and shield, then substitute a known-good DD encoder only after wiring is proven.
7. 7If YY is 02 after encoder replacement or battery-related work, have Okuma verify the DD encoder control data because the required values are not listed in this entry.