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Fanuc · Pulsecoder Alpha A64
Fanuc Pulsecoder Alpha A64 repair, test and alignment
Pulsecoder Alpha A64 is a Fanuc serial encoder with 65,536 counts. We test it, repair or replace it and align it to the rotor. Found on: Fanuc Alpha series servo motors. Star Automations is an independent multi-brand repair company and is not an OEM service centre.
- 25+years of servo repair, since 2000
- 3,000+customers across India
- 100+servo brands covered by our universal servo motor test equipment
- 5sites: Puducherry, Chennai, Bengaluru, Hyderabad, Delhi
- Same dayemergency repair option*
*Where the fault and parts allow. Every repaired unit returns with a printed test report.
Repair turnaround you can plan around
Send a photo of the nameplate first. We confirm whether the motor is repairable, and the quote, the same working day.
Urgent: 3 working days
Repair, encoder alignment and test, counted from the day the motor reaches the bench and the quote is approved.
Standard: 7 working days
Full repair, encoder alignment, run test under load and a printed test report.
- Free repairability check from a nameplate photo
- Printed test report with every motor
- Written warranty, terms stated on every quotation
- Pickup can be arranged; parts that must be imported are quoted with their own timeline
01Facts
Pulsecoder Alpha A64 at a glance
| Device | Pulsecoder Alpha A64 |
|---|---|
| Brand family | Fanuc |
| Type and format | Fanuc serial |
| Counts | 65,536 |
| Found on | Fanuc Alpha series servo motors |
| Connector | 17 or 19 pin round MS connector, or DB15; smaller built-in types use a two-row AMP D3100 connector |
| Pole setting for alignment | 8 pole as standard, 6 pole also found |
The Alpha A64 gives 65,536 counts per turn and, like other Fanuc serial encoders, must be indexed before the count is referenced. On the Alpha series Fanuc moved the encoders to a more compact package that often uses a short cable ending in the round connector.
02Faults
How Pulsecoder Alpha A64 encoders usually fail
- No data received from the encoder at power-up, usually a cable, connector or encoder board fault
- Internal error flag set by the encoder, which normally means repair or replacement
- Battery alarm or lost absolute position after a backup supply fault
- Overheat flag stuck on after thermal line or board damage
- Count that does not match one revolution, or commutation that no longer lines up with the rotor
- Encoder not indexed, so the drive never gets a referenced position
02+Alarms
Pulsecoder Alpha A64 alarms and error codes: what they mean and what to check
These are the alarms most often seen with the Pulsecoder Alpha A64 feedback device, with what each usually means and what to check first. Many encoder alarms are caused by the cable, connector or battery, not the encoder, so the checks below can save a repair.
| Alarm | Usually means | Check first |
|---|---|---|
| SV0300 | Absolute position not yet referenced, often after a battery loss, a long power-off or an encoder change | Do the reference return set-up for the axis; if it keeps coming back, check the backup battery first |
| SV0301 to SV0304 | Communication, time-out, framing or parity error between the absolute Pulsecoder and the CNC | Feedback cable and connector, shield clamp, noise from power cables; swap the cable |
| SV0305 | Pulse error found by the absolute position checker | Check the cable first, then the Pulsecoder |
| SV0306 | Backup battery voltage is zero | Change the battery with the machine powered, then repeat the reference return |
| SV0307 and SV0308 | Battery voltage low, first and second warning levels | Change the battery soon; do not switch the machine off while the battery is out |
| SV0309 | Reference return cannot be completed | Move the axis further from the reference point and retry; if it still fails, check the Pulsecoder count |
| SV0360 to SV0365 | Fault reported from inside the built-in Pulsecoder: checksum, phase data, rotation speed data, clock, soft phase or LED | Rarely a cable fault; the Pulsecoder itself is usually at fault, so have it tested |
| SV0366 and SV0367 | Pulse miss and count miss inside the Pulsecoder | Contamination on the disc or a failing board; look for coolant or oil first |
| SV0368 and SV0369 | Serial data error and data transfer error on the feedback line | Connector pins, cable and shield first, then the Pulsecoder |
| SV0417 | Servo parameter invalid | After an encoder or motor change, check that the motor ID and pulses-per-turn settings match the motor |
| SV0445 and SV0453 | Soft disconnection alarm: the Pulsecoder reports no movement or no pulses | Cable break, connector or Pulsecoder; SV0453 is the form seen on Alpha i drives |
Fanuc CNCs name these alarms slightly differently between the 16i, 18i, 0i and 30i series. Match the situation, not just the number. Alarm numbers and wording change with drive series and firmware, so check the manual for your drive. Drive brand names are used only to identify alarm lists. Star Automations is an independent multi-brand repair company and is not an OEM service centre.
Typical causes and checks
- Alarm at every power-up: reseat the connector at both ends, check the encoder supply at the motor end, and look for a broken wire.
- Alarm only when the axis moves or the cable flexes: suspect a break inside the cable chain, or a shield that has come loose.
- Alarm after coolant, washdown or rain: look for moisture or corrosion in the connector and behind the encoder cover.
- Alarm at random with other drives running: check earthing and shield clamps, and keep the feedback cable away from power cables.
- Position lost after a long stop or battery change: check battery voltage and the battery cable before suspecting the encoder.
- Alarm after a motor, encoder or drive change: check the type, the motor data in the drive, and the encoder alignment, then set the reference position again.
Encoder, cable or drive?
Swap in a known-good feedback cable first. If the alarm stays, move the motor to another axis if the drives are the same type. If the alarm follows the motor, the encoder or motor needs testing. If it stays on the axis with a good motor and cable, the drive needs testing. We test the encoder, the motor and the drive, so send the nameplate if you are not sure which it is.
Related guides: Fanuc SV0368 / SV0366 alarm, Servo encoder alarms, Absolute encoder battery.
03Process
How the repair is done
Receive and identify
We read the nameplate and encoder label and confirm the exact type.
Test
Count per turn, data status, alarm flags and, where fitted, incremental lines are checked on the bench.
Repair or replace
Board, connector or sensor faults are repaired; a matched encoder is fitted where repair is not sensible.
Align
Commutation is set to the rotor and checked at every pole pair using the electrical angle.
Verify and report
The motor is run on the bench and the readings are recorded in the report.
See encoder alignment, memory programming and replacement.
04Related
Other Fanuc encoders we repair
- Fanuc ABS and incremental
- Fanuc Pulsecoder A
- Fanuc Pulsecoder Alpha 1000A
- Fanuc Pulsecoder Alpha 1000iA
- Fanuc Pulsecoder Alpha 1000iI
- Fanuc Pulsecoder Alpha I8 and A8
- Fanuc Pulsecoder Alpha I64
- Fanuc Pulsecoder Alpha I64i and A64i
- Fanuc Pulsecoder B
- Fanuc Pulsecoder B2
- Fanuc Pulsecoder Beta A64B
- Fanuc Pulsecoder Beta A128i
- Fanuc Pulsecoder Beta I32B and A32B
- Fanuc Pulsecoder Beta I64B
- Fanuc Pulsecoder C
- All Fanuc Pulsecoder
05FAQ
Questions
What do encoder alarms on a Pulsecoder Alpha A64 usually mean?
Most fall into four groups: no communication, corrupted data, a fault reported by the encoder itself, and lost battery backup or position. The alarm table on this page lists the common codes and the first check for each.
How can I tell whether the Pulsecoder Alpha A64 encoder, the cable or the drive is at fault?
Swap in a known-good feedback cable, then move the motor to another axis if possible. If the alarm follows the motor, the encoder needs testing; if it stays on the axis, the drive does. A cable or battery fault can be fixed without sending anything.
Can you repair a Pulsecoder Alpha A64 encoder?
Yes. We test the position count and status, repair or replace the encoder, align it to the rotor and run the motor. We repair Fanuc units; Star Automations is an independent multi-brand repair company and is not an OEM service centre.
Does the Alpha A64 need to be indexed?
Yes. The index status shows OK once the encoder has been turned past its index position. Many other serial encoders do not need this step.
How many counts per turn does the Alpha A64 give?
65,536 counts per turn.
What should I send for a Pulsecoder Alpha A64 enquiry?
A clear photo of the motor nameplate and, if the cover is off, the encoder label. You can send the motor or only the encoder.
06Enquiry
Send the nameplate or encoder label
A clear photo of the motor nameplate and, if the cover is off, the encoder label is enough to start. We reply with whether it can be repaired and a quote.
Message received
Our team replies by email or WhatsApp, usually the same working day. For a line-down motor, WhatsApp +91 97866 22233.
→How it works
From nameplate photo to a tested motor in 7 steps
One route for servo motors, encoders and drives. You see the price before any work starts, and the report before the unit leaves our bench.
- 1 · Nameplate photoSend it on WhatsApp or the form
- 2 · Repairable? QuoteUsually the same working day
- 3 · Courier or pickupThe unit reaches our bench
- 4 · Bench diagnosisInsulation, windings, brake, encoder
- 5 · RepairFailed parts, bearings, seals, brake
- 6 · Align and run-testEncoder aligned; no-load and load run
- 7 · Report and dispatchPrinted test report with the unit
- Line down?Servo Swap ships a tested unit first. How Servo Swap works
EmergencySame day*
Urgent3 working days
Standard7 working days
*Where the fault and parts allow. Turnaround counts from when the unit reaches our bench and the quote is approved.