231-C6E0

Access Machine Parameters

Navigate to MOD function → Machine Parameters → Axis-specific parameters for the affected axis.

Always backup current parameters before making changes

Verify motEncType Setting

Check parameter motEncType matches encoder specification. Common values: 0=incremental, 1=EnDat2.1, 2=EnDat2.2, 3=SSI, 4=Fanuc serial.

Incorrect encoder type can damage encoder or control

Cross-Reference Encoder Label

Compare motEncType value with encoder nameplate data and machine documentation to ensure proper configuration.

Test After Correction

Clear alarm, perform controlled axis movement, and monitor for alarm recurrence.

Visual Cable Inspection

Inspect speed encoder cable from motor to CC unit for physical damage, pinching, or excessive bending near cable carriers.

Power down system before disconnecting encoder cables

Connection Verification

Check encoder connector at motor and CC unit for proper seating, corrosion, or bent pins. Verify X401/X402 connections on CC unit.

Cable Continuity Test

Using multimeter, test continuity of encoder cable conductors. For EnDat encoders, verify DATA+/DATA- and CLOCK+/CLOCK- pairs.

Signal Quality Check

Use oscilloscope to verify encoder signal amplitude and quality at CC unit input terminals during slow manual axis movement.

Access PWM Configuration

Navigate to machine parameters and locate pwmSignalOutput section for the affected axis drive configuration.

Verify analogOffset Setting

Check analogOffset parameter matches encoder feedback wiring. Typical values: 0=single-ended, 1=differential, 2=EnDat.

Cross-Reference Wiring Diagram

Compare parameter setting with machine electrical drawings to confirm encoder signal routing to CC unit inputs.

Update Configuration

Correct analogOffset parameter to match actual wiring, save parameters, and restart control to activate changes.

Encoder Signal Analysis

Monitor encoder output signals with oscilloscope during manual axis rotation to identify amplitude irregularities or dropouts.

Temperature Sensitivity Test

Check if alarm occurs consistently or only after machine warmup, indicating thermal-related encoder degradation.

Encoder Replacement

Replace speed encoder with identical part number, ensuring proper mounting alignment and cable routing.

Encoder replacement requires axis homing and potentially machine geometry compensation

Input Circuit Verification

Test CC unit encoder input terminals for proper supply voltages and reference signals per Heidenhain specifications.

Cross-Axis Comparison

Compare encoder signal processing on other axes to isolate CC unit channel-specific failures.

CC Unit Replacement

Replace CC controller unit following Heidenhain procedures, including parameter backup and restoration.

CC unit replacement requires factory-trained technician and specialized tools