231-8CB0

Check encoder signals in diagnostic screen

Navigate to MOD > Diagnosis > Axis > select affected axis > Encoder signals. Verify sine/cosine commutation signals are present and within ±1V range.

Look for signal amplitude imbalance or DC offset - healthy signals should be symmetrical

Inspect encoder cable connections

Check encoder cable at motor and drive connections. Verify proper shielding, no damaged conductors, and secure connector engagement.

Power down axis drive before disconnecting encoder cables

Perform encoder test

Use TNC Test Run function (MOD > Machine > Test Run > Encoder test) to verify encoder functionality and commutation track integrity.

Compare readings with known good axis if available

Replace encoder if faulty

If commutation signals are absent or corrupted, replace the encoder assembly and perform motor parameter setup.

Ensure exact encoder model replacement to maintain machine parameter compatibility

Verify motor pole pair parameter

Check MP1020 (pole pair number) matches motor nameplate specification. Access via MOD > Machine Parameters > Axis-specific parameters.

Pole pairs = motor poles ÷ 2. Common values are 2, 3, or 4 pole pairs

Confirm encoder resolution settings

Verify MP1010 (encoder resolution) and MP1030 (commutation encoder resolution) match encoder specifications exactly.

Incorrect encoder resolution will cause commutation errors and potential motor damage

Check commutation offset parameter

Verify MP1040 (commutation offset angle) is properly set. If unknown, set to 0 and perform automatic commutation setup.

Use automatic commutation learning if drive supports it - more accurate than manual setup

Reload motor parameters

After parameter corrections, cycle power to axis drive and perform reference point approach to validate commutation.

Ensure motor can move freely before enabling drive

Check drive status LEDs

Examine drive front panel LEDs for fault indicators. Red LED typically indicates internal drive fault requiring service.

Consult drive manual for specific LED fault code interpretation

Review drive internal diagnostics

Access drive diagnostics via TNC (MOD > Diagnosis > Drive) or drive service software to identify specific commutation circuit faults.

Some drive diagnostics require service-level access codes

Perform drive self-test

Execute drive internal self-test routine if available. This tests commutation processing circuits and encoder interface.

Document any fault codes for technician reference

Replace drive amplifier

If internal commutation circuits are faulty, drive replacement is required. Transfer parameters from backup or documentation.

Ensure exact drive model replacement and proper parameter transfer

Measure motor winding resistance

With drive disabled, measure resistance between motor phases (U-V, V-W, W-U). Values should be equal within 5% and match motor specifications.

Ensure drive is completely powered down before resistance measurements

Check motor cable connections

Inspect motor power cable connections at motor junction box and drive terminals. Look for loose, corroded, or damaged connections.

Use thermal imaging if available - poor connections show as hot spots

Test insulation resistance

Perform insulation test between motor windings and ground using megohmmeter. Should read >10MΩ for healthy motor.

Disconnect motor cable from drive before insulation testing

Replace motor if faulty

If winding faults are confirmed, replace motor and perform complete setup including encoder alignment and parameter configuration.

Mark motor mounting position before removal to maintain mechanical alignment