CNC CPU Board – MITSUBISHI RF203
The RF203 is a CNC CPU control board (“CNC CPU Board”) manufactured by Mitsubishi Electric, a component of the MELDAS numerical control line for machining centres and CNC machine tools. The board handles main part-program processing, axis management and communication with peripheral modules of the CNC system. Multiple hardware revisions are documented; the board integrates into the control rack via a dedicated internal bus.
The CPU board is the computational heart of the numerical control: it interprets the ISO/G-code part program, calculates axis trajectories in real time and coordinates all CNC subsystems (servo drives, I/O modules, operator interface). A CPU failure causes an immediate machine stop and makes any machining impossible; diagnosis is critical because faults often manifest as system errors that are not immediately traceable to the board itself.
Mitsubishi Electric is one of the world’s leading manufacturers of CNC numerical controls, with the MELDAS line serving machine shops worldwide for over forty years. Products of this generation are legacy / discontinued: official support has ended and spare parts are available exclusively through used, surplus or specialist repair channels.
Main Technical Specifications
| Type | CNC CPU control board (CNC CPU Board) |
| Part number | RF203 |
| Brand | Mitsubishi Electric |
| Known application | Mitsubishi MELDAS series CNC controllers (verify compatibility against machine documentation) |
| Function | Part-program processing, axis management, CNC subsystem coordination |
| Processor | Dedicated CPU for real-time processing (specifications to be verified against original documentation) |
| Supply voltage | +5 V DC / ±12 V DC via rack bus (typical) |
| Interfaces | CNC rack internal bus; serial and parallel connectors to I/O modules and servo drives |
| Memory | RAM and ROM/EPROM for firmware and part programs (capacity to be verified against documentation) |
| Axis compatibility | Multi-axis (exact number to be verified against original documentation) |
| Weight | ~0.3–0.8 kg |
| Dimensions | ~200–350 mm |
| Production status | Legacy / discontinued — used/surplus/repair only |
CNC CPU Board – Mitsubishi SE-CPU2
The SE-CPU2 is a CNC central processing unit board (“CNC CPU Board”) manufactured by Mitsubishi Electric, and serves as the main computing component of the MELDAS series CNC control systems. The board integrates the main processor, program memory (Flash/EEPROM) and working memory (RAM), managing part program execution, axis interpolation and communication with peripheral modules via the system’s proprietary bus. Available in the SE-CPU2 variant, it may exist in different hardware revisions; compatibility with the installed CNC system software version must be verified before replacement.
The CPU board is the computational core of the CNC controller: it performs real-time axis interpolation, interprets ISO/G-code part programs and coordinates the operation of all system modules (axes, spindle, I/O, serial communications). A CPU board failure results in a complete machine stoppage — no movement is possible without this component, making its replacement or repair an absolute priority for production recovery.
Mitsubishi Electric is one of the world’s leading manufacturers of CNC systems and industrial automation, with the MELDAS line — now evolved into the MELDASMAGIC and M800/M80 series — installed in thousands of machine tools worldwide. Products in the SE series are legacy / discontinued: available exclusively as used, surplus, or through specialist repair service.
Main Technical Specifications
| Type | CNC central processing unit board (CNC CPU Board) |
| Part number | SE-CPU2 (SECPU2) |
| Brand | Mitsubishi Electric |
| Known application | Mitsubishi MELDAS series CNC systems (CNC machine tools) |
| Function | CNC central processing: real-time axis interpolation, ISO/G-code part program execution, system bus and peripheral module management |
| Supply voltage | +5 V DC (logic), ±12 V DC (typical for this series) |
| Memory | Flash/EEPROM for OS and firmware + RAM for working data |
| Interfaces | Mitsubishi MELDAS proprietary bus; backplane rack connectors |
| Serial communications | RS-232C / RS-422 (typical for MELDAS series) |
| Software compatibility | Verify hardware revision and MELDAS OS version before replacement |
| Weight | ~0.3–0.8 kg |
| Dimensions | ~200–350 mm |
| Production status | Legacy / discontinued — used/surplus/repair only |
Absolute Optical Encoder – MITSUBISHI OSA104S2
The OSA104S2 is an absolute optical multi-turn encoder (“Optical Serial Absolute Encoder”) manufactured by Mitsubishi Electric, designed to be mounted directly on the shaft of AC servo motors of the HC and HA series, compatible with MR-J2S and MR-J3 servo drives. The device transmits the absolute multi-turn angular position to the CNC or drive via Mitsubishi’s proprietary serial protocol. The S2 suffix identifies the motor-side connector variant.
The absolute encoder is the position transducer that allows the servo drive to know the exact angular position of the motor at any instant, without the need for a homing procedure at power-up. In the event of failure, the axis becomes uncontrollable: the CNC raises a position alarm and stops the machine, making any machining operation impossible until the component is replaced.
Mitsubishi Electric is one of the world’s leading industrial automation manufacturers, with an established range of servo systems (MR-J series) and CNC controllers (MELDAS / M800 series). Products in the OSA104 family were widely used in servo systems throughout the 1990s–2010s; some variants are legacy / discontinued and available only as used, surplus or compatible replacement.
Main Technical Specifications
| Type | Absolute optical multi-turn encoder (Optical Serial Absolute Encoder) |
| Part number | OSA104S2 |
| Brand | Mitsubishi Electric |
| Known application | AC servo motors HC / HA series with MR-J2S, MR-J3 drives – MELDAS CNC systems |
| Function | Absolute multi-turn angular position transduction for position and speed loop closure |
| Resolution | 131 072 p/r – 17 bit |
| Output signal type | Mitsubishi proprietary asynchronous serial (SSA protocol) |
| Supply voltage | 5 V DC ±5 % (typical) |
| Current consumption | ~200 mA |
| Connector | S2 type – Mitsubishi-specific motor-side connector |
| Operating temperature | 0 – +55 °C (typical for series) |
| Weight | ~0.2–0.5 kg |
| Dimensions | ~ø60–80 × 40–60 mm |
| Production status | Legacy / discontinued — available as used / surplus / repair only |
AC Servo Amplifier – MITSUBISHI MR-S11-200-E01
The MR-S11-200-E01 is an AC servo amplifier (“AC Servo Amplifier”) from the MELSERVO MR-S11 series by Mitsubishi Electric, documented for use with MELDAS CNC systems (Mitsubishi Electric CNC). The suffix 200 denotes the nominal power class of 200 W, while E01 identifies the variant or firmware / motor parameter revision. The unit manages the speed and position loops of the servo axis, receiving analogue or pulse-train references from the CNC controller and driving HC series brushless servo motors by Mitsubishi. Variants may exist with different encoder interfaces or alternative current profiles.
The servo amplifier is the component that converts the position and speed reference issued by the CNC into modulated three-phase current for the motor: it controls speed, acceleration and torque of the work axis in real time. In the event of failure, the controlled axis loses precise motion entirely, making any machining operation impossible; the CNC raises position or following-error alarms and halts the machine in a protective state.
Mitsubishi Electric is one of the world’s leading manufacturers of industrial automation, with its Factory Automation (FA) division specialising in CNC controllers (MELDAS, M70, M80 series), servo drives (MELSERVO), inverters and PLCs (MELSEC). Products of the MR-S11 series are legacy / discontinued, superseded by the later generations MR-J2S, MR-J3, MR-J4 and MR-J5: available as used, surplus or through specialist repair only.
Main Technical Specifications
| Type | AC Servo Amplifier |
| Part number | MR-S11-200-E01 (MRS11200E01) |
| Brand | Mitsubishi Electric – MELSERVO division |
| Known application | Mitsubishi MELDAS CNC systems; machine tools with HC series brushless servo axes |
| Function | Servo axis control: speed, position and torque regulation of brushless motor |
| Rated power | 200 W |
| Power supply | Three-phase 200–230 V AC, 50/60 Hz (typical MR-S11 series) |
| Command interface | Analogue reference (±10 V) or pulse train; digital I/O signals |
| Compatible motor | Mitsubishi HC series brushless servo motors (e.g. HC-MF, HC-SF) – 200 W |
| Feedback | Incremental serial encoder (Mitsubishi proprietary interface) |
| Weight | ~0.8–1.5 kg |
| Dimensions | ~130–180 mm × 60–80 mm × 130–160 mm |
| Production status | Legacy / discontinued — used/surplus/repair only |
CNC Axis Servo Amplifier – Mitsubishi MR-S12-80A-E01
The MR-S12-80A-E01 is an AC servo amplifier for CNC axis drives (“AC Servo Amplifier”) from the MELSERVO MR-S series, manufactured by Mitsubishi Electric. Rated at a continuous output current of 80 A, it is designed to drive AC servo motors on the feed axes of CNC machine tools equipped with a MELDAS controller (M60/M64/M500 series and derivatives). The suffix E01 identifies the specific product variant and revision. Communication with the CNC controller is via a dedicated serial bus (SSCNET) or analogue reference ±10 V; position feedback is handled via an incremental or absolute encoder mounted on the servo motor.
The servo amplifier converts the position and velocity commands from the CNC into power current applied to the servo motor windings, simultaneously closing the current, speed and position loops to ensure faithful tracking of the machining profile. In the event of failure the controlled axis is immobilised or loses positioning accuracy, making any machining operation impossible; in multi-axis systems, the failure of a single drive halts the entire machine.
Mitsubishi Electric is one of the world’s leading manufacturers of motion control and CNC systems, with the MELSERVO division producing AC servo amplifiers and motors for industrial automation and machine tools since the 1980s. The MR-S series is a legacy / discontinued family, superseded by the MR-J2, MR-J3 and MR-J4 generations; spare parts are available exclusively as used, NOS (new old stock) or through specialist repair services.
Main Technical Specifications
| Type | AC Servo Amplifier – CNC axis drive (MELSERVO MR-S series) |
| Part number | MR-S12-80A-E01 (MRS1280AE01) |
| Brand | Mitsubishi Electric – MELSERVO (legacy MR-S series) |
| Known application | CNC machine tools with Mitsubishi MELDAS controller (M60, M64, M64S, M500 series) |
| Function | AC servo motor drive for CNC axis – current, speed and position regulation |
| Rated output current | 80 A |
| Power supply | 3× AC 200–230 V, 50/60 Hz (typical) |
| DC bus voltage | ~280–320 V DC (typical) |
| CNC interface | SSCNET (dedicated serial bus) / analogue reference ±10 V |
| Feedback | Incremental or absolute encoder on servo motor |
| Built-in protections | Overcurrent, overtemperature, DC bus overvoltage, encoder fault |
| Weight | ~4–8 kg |
| Dimensions | ~150×300×200 mm |
| Production status | Legacy / discontinued — used/surplus/repair only |
Servo Drive – MITSUBISHI MR-S12-40A
The MR-S12-40A is an analogue servo drive (“Servo Amplifier”) from the MELSERVO MR-S series manufactured by Mitsubishi Electric. It belongs to the analogue generation of Mitsubishi servo amplifiers and is designed for closed-loop control of AC brushless servo motors in CNC applications (machining centres, lathes, milling machines). It accepts an analogue speed reference, manages the current and speed control loops, and returns status signals to the controller. The model designation indicates a nominal output current of 40 A, suitable for medium-power servo motors typically paired with the main linear axes. This is a legacy component, direct predecessor of the MR-J, MR-J2S, and MR-J4 series.
The servo drive is the electronic heart of the axis control chain: it receives the position or speed reference from the CNC, closes the feedback loop on the motor encoder, and generates the current required to maintain precise positioning during machining. A drive failure completely disables the corresponding axis, rendering the machine inoperable; degraded operation causes position errors, vibration, and dimensional rejects in the workpiece.
Mitsubishi Electric is one of the world’s leading industrial automation and motion control manufacturers, with the MELSERVO line present in the CNC market since 1981. The MR-S series represents the analogue generation of Mitsubishi drives, now fully superseded by the digital MR-J4 and MR-J5 platforms. All products in the MR-S12 family are legacy / discontinued: available exclusively as used, NOS (New Old Stock), or through specialist repair services.
Main Technical Specifications
| Type | Analogue servo drive / servo amplifier |
| Part number | MR-S12-40A (MRS1240A) |
| Brand | Mitsubishi Electric – MELSERVO MR-S series |
| Known application | CNC machining centres, lathes and milling machines with Mitsubishi MELDAS / M-Series control (1990s–2000s generation) |
| Function | Servo motor speed and current regulation; position loop closure in cascade with the CNC |
| Power supply | 3-phase 200–230 V AC, 50/60 Hz (typical MR-S series) |
| Rated output current | 40 A (continuous) |
| Reference input | Analogue ±10 V (speed / torque) or pulse train (position) |
| Feedback | Incremental encoder from Mitsubishi HC / HA series servo motor |
| Interfaces / connectors | Edge connectors and terminal strips; digital I/O signals for alarm, enable and machine ready |
| Weight | ~3–7 kg |
| Dimensions | ~300×160×190 mm H×W×D |
| Production status | Legacy / discontinued — used / NOS / repair only |
AC Servo Drive 1 kW – MITSUBISHI MR-J2-100CT
The MR-J2-100CT is an AC servo amplifier from the MELSERVO-J2 series manufactured by Mitsubishi Electric, rated at 1 kW. It belongs to the second generation of the MELSERVO family and is designed for vector torque, speed and position control of Mitsubishi AC brushless servo motors in the HC-SF / HC-KF series. The CT suffix identifies a specific variant within the MR-J2 range. The drive is documented as a component of machining centres, CNC lathes, grinding machines and industrial automation systems equipped with Mitsubishi MELDAS CNC.
The servo drive is the heart of the controlled axis: it receives the position or speed reference from the CNC, reads the encoder feedback from the motor and generates the current required to follow the motion profile with maximum accuracy. In the event of a failure, the axis loses movement completely: the machine trips an alarm and cannot resume machining until the drive is replaced or repaired.
Mitsubishi Electric is one of the world’s leading manufacturers of CNC systems, servo drives and industrial inverters, with over a century of history in power electronics and automation. The MELSERVO-J2 series was introduced in the late 1990s and equipped millions of machines worldwide before being superseded by the J3, J4 and J5 generations. MR-J2 products are legacy / discontinued: available exclusively as used, NOS surplus or through specialist repair.
Main Technical Specifications
| Type | AC servo amplifier (AC Servo Amplifier) |
| Part number | MR-J2-100CT (MRJ2100CT) |
| Brand | Mitsubishi Electric – MELSERVO-J2 series |
| Known application | Machining centres, CNC lathes, grinding machines with Mitsubishi MELDAS CNC |
| Function | Speed, torque and position control of AC brushless servo motor |
| Rated output | 1 kW |
| Main circuit supply | 3-phase 200–230 V AC, 50/60 Hz |
| Rated output current | ~5.0 A |
| Feedback | Incremental encoder from servo motor (connector CN2) |
| Interfaces | CN1 (I/O command / analogue), CN2 (encoder), CN3 (RS-422) |
| Weight | ~1.5–2.5 kg |
| Dimensions | ~55 × 170 × 155 mm W×H×D |
| Production status | Legacy / discontinued — used/surplus/repair only |
Single-Axis AC Servo Amplifier – MITSUBISHI MDS-C1-V1-35
The MDS-C1-V1-35 is a single-axis AC servo amplifier (“Single-Axis AC Servo Amplifier”) from the MDS-C1 series by Mitsubishi Electric, documented as a component of the MELDAS M60, M64 and M700 CNC systems for numerically controlled machine tools. It receives the DC bus voltage from the MDS-C1-CV power supply unit and drives the servo motor via PWM modulation, communicating with the CNC controller through the SSCNET II optical serial bus. Compatible with Mitsubishi Electric HF and HC series servo motors. The suffix “-35” denotes a peak rated current of 35 A; the designation V1 identifies the single-axis module, as opposed to the twin-axis V2 variant.
The servo amplifier is the power module that converts position and speed commands generated by the CNC into phase current for the motor: it closes the current loop and, in cascade, the speed and position loops, ensuring axis interpolation accuracy during machining. Should it fail, the controlled axis loses all servo movement, causing an immediate machine stop; in the most critical cases an abnormal current response can trigger uncontrolled movements and severe mechanical damage.
Mitsubishi Electric is one of the world’s leading manufacturers of CNC systems and drives for machine tools, with over forty years of experience in industrial motion control. The MDS-C1 series has been superseded by the MDS-D and MDS-E/EX families; all products in the C1 family are therefore legacy / discontinued and available exclusively as used, surplus, or through specialist repair services.
Main Technical Specifications
| Type | Single-axis AC servo amplifier |
| Part number | MDS-C1-V1-35 (MDSC1V135) |
| Brand | Mitsubishi Electric |
| Known application | Mitsubishi MELDAS M60, M64, M700 CNC systems; machining centres and CNC lathes |
| Function | Current, speed and position regulation for one servo axis |
| Peak rated current | 35 A |
| Power supply | DC bus from MDS-C1-CV unit (~283–300 V DC) |
| Communication interface | SSCNET II (Mitsubishi optical synchronous serial network) |
| Number of axes | 1 (single-axis; V2 variant handles two axes) |
| Compatible motors | Mitsubishi Electric HF and HC series AC brushless servo motors |
| Weight | ~1.5–3.5 kg |
| Dimensions | ~60–120 × 180–260 × 150–210 mm |
| Production status | Legacy / discontinued — used/surplus/repair only |
Digital AC Spindle Drive – MITSUBISHI MDS-C1-SPH-300
The MDS-C1-SPH-300 is a digital AC spindle drive (“Digital AC Spindle Drive”) manufactured by Mitsubishi Electric, belonging to the MDS-C1 series. The designation SPH identifies the high-performance spindle drive variant (“Spindle High-performance”) within the series; the suffix 300 indicates a rated output power of approximately 30 kW. The unit is documented on CNC machining centres and lathes equipped with Mitsubishi CNC controllers of the M64, M65, and M700 series (MELDASMAGIC). It controls the spindle motor digitally via vector control, communicating with the CNC through the proprietary SSCNET serial bus (Servo System Controller NETwork). It can operate in a shared DC-bus configuration with MDS-C1-V servo drive units and MDS-C1-CV power supply/regenerative units.
The spindle drive receives speed and torque commands from the CNC via the SSCNET bus and precisely regulates the AC spindle motor through closed-loop vector control algorithms. Without this unit the spindle cannot be driven or speed-controlled: any fault triggers an immediate halt of machining operations and raises system alarms that lock the entire CNC installation.
Mitsubishi Electric is a division of the Mitsubishi Group, one of the world’s largest manufacturers of industrial automation, drives, and CNC systems. The MDS-C1 series is a line of digital AC drives introduced in the 1990s, now legacy / discontinued and replaced by the MDS-C2, MDS-D, and MDS-EJ2 series: available exclusively as used, surplus, or through specialist repair.
Main Technical Specifications
| Type | Digital AC spindle drive, high-performance (Digital AC Spindle Drive – High-performance) |
| Part number | MDS-C1-SPH-300 (MDSC1SPH300) |
| Brand | Mitsubishi Electric |
| Known application | CNC machining centres and lathes with Mitsubishi M64, M65, M700 (MELDASMAGIC) controller |
| Function | Digital speed and torque regulation of AC spindle motor via vector control |
| Rated output power | ~30 kW |
| Supply voltage | 3-phase AC 200 V / 400 V (model-dependent; verify nameplate) |
| CNC interface | SSCNET serial bus (Servo System Controller NETwork – Mitsubishi proprietary) |
| Feedback | Incremental encoder OSE from spindle motor |
| Cooling | Internal forced-air fan |
| Weight | ~8–15 kg |
| Dimensions | ~150 × 350 × 350 mm W×D×H |
| Production status | Legacy / discontinued — used/surplus/repair only |
Spindle Drive Amplifier – Mitsubishi MDS-C1-SPH-185
The MDS-C1-SPH-185 is an AC spindle drive amplifier (“Spindle Drive Amplifier”) from the MDS-C1 series manufactured by Mitsubishi Electric, designed for high-performance vector control of AC spindle motors in CNC machine tools. The part number decodes as: MDS (Mitsubishi Drive System), C1 (second generation of the MDS-C family), SP (Spindle), H (high-current/high-power variant) and 185 (rated output ~18.5 kW). The unit is documented on Mitsubishi CNC systems series M64, M65, M66, C6, E60 and E68, installed on vertical and horizontal machining centres, CNC lathes and milling machines from various OEM builders using Mitsubishi controls. It receives speed, torque and position references from the CNC via the SSCNET serial bus (fibre-optic or dedicated serial connector) and drives the spindle motor through an integrated IGBT power stage.
The MDS-C1-SPH-185 spindle drive amplifier is the electronic controller that governs the spindle motor’s speed, torque and angular position in vector mode: it interprets the CNC commands and maintains stable, precise rotation during cutting operations, even under varying loads. If it fails, the spindle becomes uncontrollable and the machine trips on alarm; critical functions such as rigid tapping, spindle orientation, C-axis positioning and automatic tool change become impossible, causing a complete production stoppage.
Mitsubishi Electric is one of the world’s leading manufacturers of CNC systems, servo amplifiers and motors for machine tools, part of the Mitsubishi group headquartered in Tokyo, Japan. The MDS-C1 series is legacy / discontinued: introduced in the 1990s and superseded by the later generations MDS-D, MDS-D2 and MDS-EX, it remains widely installed on machines built between the late 1990s and early 2000s, for which it is available only as used stock, NOS surplus or through specialist repair.
Main Technical Specifications
| Type | AC spindle drive amplifier (Spindle Drive Amplifier) |
| Part number | MDS-C1-SPH-185 (MDSC1SPH185) |
| Brand | Mitsubishi Electric |
| Known application | Mitsubishi CNC series M64, M65, M66, C6, E60, E68; vertical/horizontal machining centres, CNC lathes |
| Function | Vector control of AC spindle motor speed, torque and current; C-axis positioning, spindle orientation, rigid tapping support |
| Rated output power | ~18.5 kW |
| Input voltage | 3-phase 200 V AC ±10%, 50/60 Hz |
| CNC interface | SSCNET serial bus (fibre-optic / dedicated serial connector) |
| Power stage technology | IGBT (Insulated Gate Bipolar Transistor), PWM modulation |
| Operating modes | Speed control, torque control, C-axis positioning, spindle orientation, rigid tapping |
| Cooling | Integrated forced-air cooling |
| Weight | ~8–15 kg |
| Dimensions | ~300–450 × 200–280 × 150–200 mm |
| Production status | Legacy / discontinued — used/surplus/repair only |
Regenerative Converter Unit – MITSUBISHI MDS-C1-CV-300
The MDS-C1-CV-300 is a regenerative converter unit (“Regenerative Converter Unit”) manufactured by Mitsubishi Electric, belonging to the MDS-C1 servo and spindle drive series. It converts three-phase mains voltage into a regulated DC bus voltage, supplying the servo amplifier and spindle drive modules connected to the same bus. The CV-300 suffix denotes the power class of the unit (approximately 30 kW). It is documented as a component of machining centres, lathes, and multi-axis CNC machines equipped with Mitsubishi MELDAS M64 / M640 CNC controllers. The main stock part number is MDSC1CV300.
The CV converter unit is the power backbone of the entire MDS-C1 drive system: it supplies the DC bus voltage to all connected servo and spindle modules, and manages regenerative energy recovery during motor deceleration phases, feeding the energy back into the bus rather than dissipating it as heat. A failure of this module renders the entire drive chain inoperative, simultaneously blocking all machine axes and the spindle.
Mitsubishi Electric is one of the world’s leading manufacturers of CNC systems, servo motors, inverters, and industrial automation equipment, with over a century of history in the electrotechnical sector. The MDS-C1 series is a legacy / discontinued product line, now superseded by the more recent MDS-D, MDS-E, and MDS-EJ series: availability is limited to the used, surplus, and specialist repair market.
Main Technical Specifications
| Type | Regenerative converter unit (Regenerative Converter Unit) |
| Part number | MDS-C1-CV-300 (MDSC1CV300) |
| Brand | Mitsubishi Electric |
| Known application | Machining centres and CNC lathes with Mitsubishi MELDAS M64 / M640 controller |
| Function | AC→DC bus conversion; power supply for servo and spindle modules; regenerative energy recovery |
| Input voltage | 3× 200–230 V AC, 50/60 Hz (200 V class) |
| DC bus voltage | ~280–330 V DC |
| Rated power | ~30 kW (CV-300 class) |
| Interfaces/connectors | DC bus to servo/spindle modules; CN control connectors; AC mains terminal strip |
| Weight | ~8–15 kg |
| Dimensions | ~250×350×180 mm |
| Production status | Legacy / discontinued — used/surplus/repair only |
DC Bus Converter Power Supply Unit – Mitsubishi MDS-C1-CV-110
The MDS-C1-CV-110 is a DC bus converter / power supply unit (“Converter Unit”) from the MDS-C1 series by Mitsubishi Electric, designed for CNC servo and spindle drive systems. The unit converts three-phase AC mains voltage into DC bus voltage that feeds all connected servo and spindle drive modules in parallel (MDS-C1-SP and MDS-C1-V series). The designation CV identifies the converter module within the modular MDS-C1 architecture; the suffix 110 indicates the nominal power rating. Documented on CNC machines equipped with Mitsubishi M64, M70 and M700 series controls; commonly found on machining centres and CNC lathes by OEM brands such as Mazak, Mori Seiki and others. Includes DC bus connection terminals, three-phase AC input terminal strips, and status/alarm signal connectors to the CNC.
The DC bus converter is the heart of the power supply for the entire drive system: without it all connected servo drives and the spindle drive are deprived of bus voltage and the machine stops completely. A fault in the CV module manifests as missing bus voltage alarms, inability to enable axes, and automatic emergency stop; the machine cannot perform any movement or start the spindle until the unit is replaced or repaired.
Mitsubishi Electric is one of the world’s leading manufacturers of CNC systems and drives for machine tools, active in the sector for over 50 years with the MELDAS and MELSERVO product lines. The MDS-C1 series is a previous generation compared to the current MDS-D2 / MDS-E2, therefore these products are to be considered legacy / discontinued: no longer available as new from the official catalogue, obtainable only as used, surplus, or through specialist repair.
Main Technical Specifications
| Type | DC bus converter / power supply unit (Converter Unit) |
| Part number | MDS-C1-CV-110 (MDSC1CV110) |
| Brand | Mitsubishi Electric |
| Known application | Mitsubishi CNC M64, M70, M700 series; OEM machining centres and CNC lathes (Mazak, Mori Seiki) |
| Function | AC/DC conversion – DC bus supply for MDS-C1 servo and spindle modules |
| Input voltage | 3~ 200–230 V AC, 50/60 Hz |
| DC bus voltage | ~280–300 V DC (MDS-C1 series internal bus) |
| Rated power | Size 110 (~11 kW – verify against official datasheet) |
| Regeneration | Unit with regenerative braking capability (typical of CV series) |
| Interfaces | DC bus connectors, three-phase AC input terminal strips, status/alarm signals to CNC |
| Weight | ~4–8 kg |
| Dimensions | ~135–200 × 300–450 × 180–260 mm |
| Production status | Legacy / discontinued — used/surplus/repair only |
Spindle Drive Amplifier – MITSUBISHI MDS-B-SP-185
The MDS-B-SP-185 is an AC spindle amplifier (“Spindle Amplifier”) from the MDS-B series manufactured by Mitsubishi Electric, designed for vector control of AC spindle motors in CNC machine tools. It is documented as a component of Mitsubishi’s MELDAS 600, MELDAS 640 and M64 CNC systems, where it performs speed and torque regulation of the main spindle motor. The “SP” suffix identifies the spindle variant within the MDS-B family, while “185” denotes a rated output current of 185 A. It is not interchangeable with the servo-axis variants MDS-B-V1 and MDS-B-V2. Available in different input voltage ratings (200 V and 400 V classes).
The MDS-B-SP-185 spindle amplifier is the heart of the spindle regulation system: it receives speed and torque references from the CNC controller via Mitsubishi’s proprietary high-speed serial servo bus and closes the current and speed loops on the AC spindle motor, ensuring stable rotation and constant cutting power throughout the machining process. A failure of this drive causes immediate spindle shutdown and machine stop: without this module no machining cycle can be started, resulting in complete production downtime and an extraordinary maintenance intervention.
Mitsubishi Electric is one of Japan’s leading industrial electronics multinationals, with its FA (Factory Automation) division specialising in CNC systems, servo drives, inverters and industrial robots for over fifty years. The MDS-B series was manufactured from the 1990s to the early 2000s and is now legacy / discontinued: replacement models belong to the MDS-C1 and MDS-D families, which are not always plug-in compatible with existing wiring.
Main Technical Specifications
| Type | AC spindle amplifier (Spindle Drive) |
| Part number | MDS-B-SP-185 (MDSBSP185) |
| Brand | Mitsubishi Electric – FA (Factory Automation) Division |
| Known application | Mitsubishi CNC systems MELDAS 600 / MELDAS 640 / M64 – machining centres and CNC lathes |
| Function | Vector speed and torque regulation of AC spindle motor |
| Input voltage | 3~ 200–230 V AC or 380–480 V AC, 50/60 Hz (verify nameplate) |
| Rated output current | 185 A |
| Rated output power | ~18.5 kW |
| CNC interface | Mitsubishi proprietary high-speed serial servo bus |
| Feedback | Encoder / speed transducer from spindle motor |
| Cooling | Internal forced-air ventilation |
| Weight | ~10–20 kg |
| Dimensions | ~300–400 mm × 450–550 mm × 150–200 mm (W × H × D) |
| Production status | Legacy / discontinued — used/surplus/repair only |
AC Brushless Servo Motor CNC Axis – MITSUBISHI HC-MF 13-UE
The HC-MF 13-UE is an AC brushless servo motor (“AC Servo Motor”) from the HC-MF series manufactured by MITSUBISHI Electric, part of the MELSERVO product family. It is documented as an axis drive motor for CNC machine tools equipped with Mitsubishi servo amplifiers of the MR-SA, MR-J or compatible series. The UE suffix identifies a specific variant in terms of encoder or output shaft configuration. The HC-MF series is characterised by low inertia and high dynamic response, designed for rapid and precise positioning applications on machining centres, milling machines, and small to medium format CNC machines.
The servo motor is the electromechanical actuator that converts the torque and speed reference generated by the servo amplifier into precise mechanical movement of the linear or rotary axis. In a CNC machine tool, its failure results in complete loss of the affected axis: any machining operation involving that axis becomes impossible, causing immediate machine downtime and production loss. Loss of the integrated encoder signal can also trigger severe alarms on the CNC controller and potentially damage guideways if not correctly managed.
MITSUBISHI Electric is a Japanese multinational corporation and world leader in industrial automation, motion control, and power electronics. The MELSERVO family (HC-MF, HC-SF, HC-RF series and derivatives) has been a benchmark in the CNC sector since the 1980s. Products in the HC-MF series are legacy / discontinued: available exclusively as used, NOS surplus, or through specialist repair services.
Main Technical Specifications
| Type | AC brushless servo motor (AC Servo Motor) – HC-MF series |
| Part number | HC-MF 13-UE (HCMF13UE) |
| Brand | MITSUBISHI Electric – MELSERVO |
| Known application | CNC machine tools with Mitsubishi MR-SA / MR-J servo amplifiers (machining centres, milling machines, CNC lathes, industrial robots) |
| Function | CNC axis drive: conversion of electrical reference into precise mechanical motion (position / speed / torque) |
| Rated output | ~100–200 W |
| Rated speed | 3,000 rpm (typical HC-MF series) |
| Rated torque | ~0.32–0.64 Nm |
| Power supply | Via dedicated servo amplifier (three-phase / single-phase); do not connect directly to mains supply |
| Encoder / feedback | Integrated incremental encoder (UE suffix); standard Mitsubishi HC-series connector |
| Interfaces / connectors | Power connector + encoder connector (standard MELSERVO wiring) |
| Weight | ~0.5–1.5 kg |
| Dimensions | ~150–250 mm L |
| Production status | Legacy / discontinued — used / NOS surplus / specialist repair only |
AC Frequency Inverter 7.5 kW – Mitsubishi FR-SE-2-7.5K
The FR-SE-2-7.5K is an AC frequency inverter rated at 7.5 kW (“AC Frequency Inverter”) manufactured by Mitsubishi Electric, belonging to the FR-SE (Freqrol) series, designed for variable-speed control of three-phase asynchronous motors in industrial applications and CNC machine tools. The unit dynamically varies output frequency and voltage through PWM (Pulse Width Modulation) modulation to match motor speed to the machining cycle set by the numerical control. The 7.5 kW model is suitable for controlling medium-power spindles, hydraulic pumps, and auxiliary axes. The product may be available in multiple hardware revisions; some versions include an integrated operator panel and dedicated digital and analogue I/O.
The frequency inverter regulates AC motor speed by dynamically varying the supply frequency and voltage: this function is critical in CNC machine tools where spindle or auxiliary axis speed must accurately follow the parameters set by the numerical control. In the event of failure, the controlled motor loses all speed regulation and can no longer follow the CNC reference, making precision machining impossible and risking damage to the tool, workpiece, or machine itself.
Mitsubishi Electric is one of Japan’s leading multinationals in industrial automation, present in the frequency inverter market with the Freqrol (FR) line since the 1980s. The FR-SE series was a compact family designed for robust and straightforward industrial applications; all models in this series are legacy / discontinued and have been superseded by the more recent FR-E800 and FR-D800 series.
Main Technical Specifications
| Type | AC frequency inverter (AC Frequency Inverter) – FR-SE series |
| Part number | FR-SE-2-7.5K (FRSE275K) |
| Brand | Mitsubishi Electric – Freqrol FR-SE (legacy) |
| Known application | CNC machine tools; medium-power spindle, auxiliary axis and hydraulic/coolant pump speed control |
| Function | Variable-speed control of three-phase AC motor via PWM modulation; output frequency and voltage regulation |
| Rated power | 7.5 kW |
| Input voltage | 3~ 200–230 V AC, 50/60 Hz — 200 V class |
| Rated output current | ~38–42 A |
| Output frequency | 0–400 Hz (typical for FR-SE series) |
| Interfaces / connectors | Power terminal strip (R/S/T – U/V/W); control terminal strip (digital and analogue I/O ±10 V); optional operator panel |
| Weight | ~3–5 kg |
| Dimensions | ~200 × 150 × 200 mm (H × W × D) |
| Production status | Legacy / discontinued — used/surplus/repair only |
CNC Power Supply Unit – MITSUBISHI ETU-3MK0IZ
The ETU-3MK0IZ is a CNC power supply unit (“CNC Power Supply Unit”) manufactured by Mitsubishi Electric, designed to provide regulated supply voltages to all modules of the CNC system (CPU board, I/O boards, servo drives, and axis units). The code identifies a power supply unit from the MELDAS family or equivalent Mitsubishi Electric CNC series. The component is a dedicated switching unit, with specific connectors for the CNC rack internal bus. Revision variants may differ in output voltages or connector configuration.
The power supply unit is the heart of the control electronics: it generates and stabilises the DC voltages required by all modules of the CNC system. Without it the entire system remains inactive; even a partial fault — such as an out-of-tolerance output — can cause unexpected anomalies in machining cycles, loss of parameters, or damage to downstream modules.
Mitsubishi Electric is one of the world’s leading industrial automation manufacturers, with a CNC division operating under the MELDAS brand (later MELDASMAGIC and the M70/M700/M800 series). Support for legacy products is limited; components from older series are legacy / discontinued and available only as used units or through specialist repair services.
Main Technical Specifications
| Type | CNC power supply unit |
| Part number | ETU-3MK0IZ (ETU3MK0IZ) |
| Brand | Mitsubishi Electric |
| Known application | Mitsubishi Electric CNC systems MELDAS / M-series |
| Function | Generation and stabilisation of DC supply voltages for CNC modules (CPU, I/O, axes) |
| Input voltage | 100–240 V AC, 50/60 Hz |
| Output voltages | ±15 V DC, +5 V DC, +24 V DC |
| Rated power | ~50–200 W |
| Interfaces / connectors | Dedicated connectors for Mitsubishi CNC bus/rack; AC input terminal strip |
| Built-in protections | Overvoltage, overcurrent, short-circuit (typical for industrial switching PSUs) |
| Weight | ~0.8–2.5 kg |
| Dimensions | ~150–300 mm |
| Production status | Legacy / discontinued — used/surplus/repair only |
Analog-to-Digital Converter Module – MITSUBISHI ADC-04D
The ADC-04D is an analog-to-digital converter module (“Analog-to-Digital Converter Module”) manufactured by Mitsubishi Electric, designed for CNC and industrial automation control systems of the MELDAS series and compatible architectures. The unit acquires analog voltage or current signals from sensors, transducers, or potentiometers and converts them into digital values that can be processed by the CNC controller. The designation ADC-04D identifies a converter with 4 independent analog input channels; the trailing letter “D” denotes the hardware variant or revision. Depending on the host system architecture, it may be installed as a plug-in board on a backplane or as a standalone module.
The A/D converter module performs an essential role in bridging the physical world of analog signals and the digital logic of the numerical controller: without it the CNC cannot read continuous quantities such as positions, temperatures, pressures, or speeds. A failure in the converter manifests as incorrect or missing feedback channel readings, feedback alarms, and immediate machine stops, making any machining cycle impossible.
Mitsubishi Electric is one of Japan’s largest multinational electronics and industrial automation conglomerates, with over a century of history. Its FA (Factory Automation) division produces the world-class MELDAS / M700 / M800 CNC controller series, MELSERVO servo drives, and MELSEC PLCs. Products in the ADC-04D family belong to earlier-generation control architectures and are to be considered legacy / discontinued: availability is limited to the used market and specialist repair services.
Main Technical Specifications
| Type | Analog-to-Digital Converter Module |
| Part number | ADC-04D (ADC04D) |
| Brand | Mitsubishi Electric |
| Known application | Mitsubishi Electric CNC/FA systems, MELDAS series and compatible |
| Function | Analog-to-digital signal conversion for the CNC controller – 4 independent channels |
| Number of channels | 4 independent analog input channels |
| Analog input range | ±10 V DC or 0–10 V DC (typical Mitsubishi CNC systems) |
| Resolution | 12-bit, typical for industrial A/D converters in this series |
| Supply voltage | +5 V DC and ±15 V DC (typical Mitsubishi CNC backplane) |
| Interfaces / connectors | Backplane connector for CNC internal bus; analog input terminal strip |
| Weight | ~0.2–0.6 kg |
| Dimensions | ~150–250 mm |
| Production status | Legacy / discontinued — used/surplus/repair only |