2136

Common Causes

• DD encoder failure (internal absolute position sensor error)
• Encoder gap too narrow or too wide (codes 42/43) after mechanical disturbance
• Encoder inclination out of tolerance (codes 40/41)
• Communication error between encoder and drive (code 21 or XX bit2 toggling)

Troubleshooting Steps

1. 1Read the code number shown with the alarm: code 01 = Stop command has stopped; code 02 = Control parameter error in the encoder; code 04 = Absolutization error - absolute position could not be established; code 05 = Initialization speed too high; code 08 = Auto-set data error; code 0D = Speed too high; code 0E = Synchronization error; code 20 = Absolutization mismatch (Format-5 only)
2. 2Read the code on screen: the first two hex digits (XX) are status bits and the middle two (YY) are the actual alarm code; branch on YY.
3. 3Code 42 or 43 (gap narrow/wide) or 40/41 (inclination): inspect the DD encoder mounting for looseness, impact damage, or a shifted read head, and correct the mechanical gap/inclination before anything else.
4. 4Code 21 or a toggling bit2 in XX (communication error): check the encoder cable and connectors for damage, poor seating, or coolant ingress along the full run to the drive.
5. 5Code 02 (control parameter error) or 08 (auto-set-data error): the encoder setup data is suspect; have the encoder re-initialized/auto-set per the machine builder's procedure.
6. 6Code 0D or 05 (speed too high): check whether the axis/spindle was moved faster than allowed during initialization, e.g. by external force on a DD table.
7. 7If the mechanical condition and cabling are good and the error returns, the DD encoder itself is the probable faulty part; record the full XXYYZZZZ code and contact Okuma service.