Mitsubishi MR-J4W2-77B 2-axis integrated servo drive

MR-J4: MELSERVO-J4 servo series

W2: 2-axis integrated drive (one unit controls 2 motoare)

77: Rated power of each axis: 750W + 750W

B: SSCNETⅢ/H fiber bus interface for fiber synchronous control, compatibil cu Mitsubishi motion CPUs

📋 Main Specifications

🛠️ Compatible Motors

Compatible with Mitsubishi HG-MR73 / HG-KR73 (750W J4-series servo motors), supporting absolute encoders.

🎯 Aplicații tipice

Multi-axis synchronous equipment: chip mounters, inspection platforms, module de transfer, CNC auxiliary machines, utilaje de ambalare, echipamente semiconductoare.

Avantaj: Two axes share one drive, saving cabinet space and reducing cost.

🔄 Replacement Options

1. Upgrade to new generation (J5)：MR-J5W2-77B (same 2-axis rating, SSCNETⅢ/H compatible, performanță îmbunătățită)
2. Separate drive solution：2 pcs MR-J4-70B (single-axis 750W, larger footprint)
3. Înlocuire moștenire：Predecessor MR-J3W-77B. Wiring and program differences, nu plug-and-play

This is a bus-type servomotor; pulse command control is not supported directly. It must be used with Mitsubishi motion controllers (Q/R series motion CPU) via SSCNET fiber link.

USB port for commissioning; configured with MR Configurator2 software.

Piese de schimb: Power board, CPU board, CNP connector with individual part numbers (303772, 303769, etc.)

MR-J4W2 (MR-J4W2-77B) Alarma / Fault Code List

Descriere: MR-J4W2 2-axis integrated type B (SSCNETⅢ/H). Alarms are divided into fault alarms (latched, reset required) and warnings (nicio oprire, prompt only).

Sufix .1/.2 stands for Axis 1 / Axă 2, which is critical for this 2-axis model.

Readout: Drive panel or MR Configurator2 software; alarm history can be saved with waveform data for troubleshooting.

1. Fault Alarms (ALM, machine shutdown)

2. Alarm Code	Nume	Brief Cause & Depanare
   10	Subtensiune	Insufficient DC bus voltage; missing phase, voltage drop, poor contact of contactor, damaged rectifier module
   12	Memory error	Internal ROM / flash failure; replace drive if fault persists after power cycle
   13	Clock error	Internal RTC failure; drive replacement is generally required
   15	Power circuit error	Pre-charge / soft-start circuit failure on main power side
   16	Defecțiune la pământ	Short to earth of motor power cable, motor winding insulation breakdown
   19	Main circuit error	IPM or power driver hardware damage
   1O	Motor combination error	Mismatched motor model in PA01/PA02; wrong encoder cable or motor selection (.1 Axis1, .2 Axis2)
   20	Encoder initial communication error	Handshake failure at power-up; broken encoder cable, loose connector, codificator defect
   24	Encoder communication error	Communication dropout during operation; EMI interference, poor shield on long cable, water ingress in connector
   25	Encoder Z-phase error	Abnormal encoder zero signal
   2B	Encoder counting error	Count disorder caused by interference or encoder hardware failure (.1 Axis1, .2 Axis2)
   30	Regeneration error	Broken regenerative resistor, wrong resistance value, excessive regenerative power; built-in regeneration insufficient, external resistor required
   31	Viteză excesivă	Motor speed exceeds limit; abnormal command, encoder feedback fault, runaway due to excessive gain
   32	Supracurent	Hardware / software overcurrent; phase-to-phase short circuit in motor, shorted power wire, IPM breakdown, blocaj mecanic
   33	Supratensiune	DC bus over-limit; excessive energy feedback during deceleration, high input voltage, failed regeneration circuit
   34	SSCNET receive error 1	SSCNETⅢ/H fiber communication fault: bent fiber, contaminated end face, loose connector, faulty fiber port on motion CPU
   35	Command frequency error	Illegal command sent from upper motion controller
   36	SSCNET receive error 2	Fiber synchronization timing error, multi-axis link synchronization fault
   37	Parameter error	Parameter out of range or checksum error; restore factory settings and re-download parameters
   3O	Surge suppression circuit error	Soft-start circuit failure at power-on
   3E	Operation mode error	Mismatch between control mode parameter and SSCNET configuration on master side
   42	Full-closed control error	External linear scale feedback fault (only for full-closed loop mode)
   45	Main device overheat	Power module overheat; blocked cooling air duct, fan stall, temperatura ambientala ridicata
   46	Supraîncălzirea motorului	Motor thermal sensor triggered; continuous overload, poor motor heat dissipation (.1 Axis1, .2 Axis2)
   47	Cooling fan fault	Drive internal fan stall / viteză mică; blocarea obiectelor străine, fan aging
   50	Supraîncărcare 1	Supraîncărcare continuă (electronic thermal protection); mechanical binding, high friction, undersized selection
   51	Supraîncărcare 2	Peak overload; impact load, sudden mechanical lock
   52	Position excessive error	Position deviation exceeds threshold; lost pulses, blocaj mecanic, low gain, excessive command speed (.1 Axis1, .2 Axis2)
   54	Detectarea vibrațiilor	Servo oscillation; excessive gain, mechanical resonance
   56	Forced stop alarm	STO safety circuit open, emergency stop triggered, disconnected STO wiring
   61	Operation error	Illegal command while servo ON, sequence control error
   63	STO timing error	Timing mismatch between two STO channels, asymmetric safety wiring
   64	Safety setting error	Incorrect STO safety parameter configuration

   Avertismente (WARN, servo keeps running, alert only)

Special Notes for MR-J4W2 2-Axis Drive

1. Sufix .1 = CH1 (Axă 1)；.2 = CH2 (Axă 2). Confirm faulty axis first; motor and encoder of the two axes are independent.
2. EB warning is unique to this multi-axis model: When one axis faults, the other axis reports EB to indicate the companion axis failure. Do not troubleshoot EB directly; check the real alarm code on the other channel.
3. 34 / 36 fiber alarms: For SSCNETⅢ/H fiber, clean end face first, minimum bend radius ≥30mm, avoid sharp bends.
4. STO (56, 63, 95): Two STO channels must switch synchronously; inconsistent timing triggers code 63.
5. Alarm reset: Remove root cause first, turn servo SON OFF then reset. Some hardware faults cannot be cleared by power cycling.

Mitsubishi MELSERVO Servo Drive Model List

General suffix definition

O: Puls + analog interface (pulse command type)

B: SSCNETⅢ/H fiber bus (fiber synchronization with motion CPU, MR-J4W2-77B belongs to this type)

GF / G: CC-Link IE / CC-Link IE TSN Ethernet bus

W2: 2-axis integrated; W3: 3-axis integrated

D1/D2/D3: Separate power type (amplifier unit paired with MR-CV power supply)

Numeric code for power rating (10= 0,1 kW, 20= 0,2 kW, 40= 0,4 kW, 60=0.6kW, 70=0,75 kW, 100=1kW, 200=2kW, 350=3.5kW, 500=5kW, 700=7kW)

RJ: Special specification version

Active Series (Available for new orders)

1. MR-J5 Series (Latest generation, MELSERVO-J5, 3.5kHz response)

O singură axă

MR-J5-10A / 20O / 40O / 60O / 70O / 100O / 200O / 350O / 500O / 700A 【Pulse type】

MR-J5-10G / 20G / 40G / 70G / 100G / 200G / 350G / 500G / 700G 【CC-Link IE TSN】

MR-J5-10B / 20B / 40B / 70B / 100B / 200B / 350B 【SSCNETⅢ/H fiber】

Multi-axis integrated

MR-J5W2-22B / 44B / 77B / 1010B / 2020B (2-axă, SSCNET fiber)

MR-J5W3-222B / 444B / 777B (3-axă, SSCNET fiber)

MR-J5W2-22G / 44G / 77G / 1010G (2-axă, CC-Link IE TSN)

MR-J5W3-222G / 444G / 777G (3-axă, CC-Link IE TSN)

Separate power type (Common DC bus regeneration system)

MR-J5D1-G4-N1 (1-axă), MR-J5D2-G4-N1 (2-axă), MR-J5D3-G4-N1 (3-axă)

Matching power unit: MR-CV4 regenerative converter

2. MR-J4 Series (Mature mainstream, your model belongs here)

O singură axă

MR-J4-10A / 20O / 40O / 60O / 70O / 100O / 200O / 350O / 500O / 700O / 11THE / 15THE / 22THE

MR-J4-10B / 20B / 40B / 60B / 70B / 100B / 200B / 350B / 500B / 700B (SSCNETⅢ/H)

MR-J4-10GF / 20GF / 40GF / 70GF / 100GF (CC-Link IE Field)

Multi-axis integrated (Focus: MR-J4W2 / J4W3)

MR-J4W2-22B (0.2+0.2kW)

MR-J4W2-44B (0.4+0.4kW)

MR-J4W2-77B (0.75+0.75kW, modelul dvs)

MR-J4W2-1010B (1+1kW)

MR-J4W2-2020B (2+2kW)

MR-J4W3-222B / 444B / 777B (3-axis integrated)

MR-J4W2-0303B6 (Low-power special version)

Separate amplifier unit

MR-J4-DU900B / DU11KB / DU15KB / DU22KB, used with MR-CV regenerative power supply

3. MR-JE Economy Series (Low-cost, puls / simple bus, low power range)

MR-JE-10A / 20O / 40O / 70O / 100O / 200O

MR-JE-10C / 20C / 40C / 70C (EtherCAT version, JE-C)

Aplicație: Simple feeding and transfer; SSCNET fiber multi-axis synchronization is not supported

4. MR-JN Micro Economy Series (Ultra compact, 10~100W)

MR-JN-10A / 20O / 40O / 60O / 100O

Aplicație: Small rotary tables, miniature slides, entry-level low-power

⏸️ Obsolete Series (Spare parts market only, not recommended for new machines)

MR-J3 (Production discontinued, stock spares reducing)

O singură axă: MR-J3-10A /20A/40A/70A/100A/200A/350A / MR-J3-10B/20B/40B/70B

Multi-axa: MR-J3W-22B / MR-J3W-44B / MR-J3W-77B (J3 2-axis, predecessor of J4W2)

CC-Link version: MR-J3-10T / 20T /40T

MR-J2S (Moştenire, manufacturer repair service terminated)

MR-J2S-10A/20A/40A/70A/100A/200A/350A, MR-J2S-10B, MR-J2S-CP (built-in positioning type)

MR-J2 (Erly first generation, nearly phased out)

MR-J2-10A、MR-J2-20A, etc.

📌 Auxiliary Units (Common servo system accessories)

MR-CV: Regenerative power converter (common DC bus system for J4/J5D)

MR-RB: External regenerative braking resistor

MR-TB: Terminal block adapter

📎 Quick Selection Reference for MR-J4W2-77B

Same-series replacement: MR-J4W2-77B

Upgrade to new generation: MR-J5W2-77B (SSCNET compatible, preferred direct upgrade)

Separate drive alternative: 2 pcs MR-J4-70B

Economy alternative: JE series does not support SSCNET fiber, cannot replace directly