Mitsubishi MELDAS M64 Backup & Restore Procedure — Parameters, Programs, Offsets & PLC

The Mitsubishi MELDAS M60/M64/M65 series (late 1990s – mid 2000s) stores parameters, programs, offsets and PLC data in battery-backed SRAM. When the battery fails or a control board is replaced, everything is gone — and unlike the newer M70/M80, there is no front USB port. Backups are done over RS-232 from the Data In/Out screen (some machines also have a PCMCIA/IC card slot on the control unit). Here is the complete backup and restore procedure for an M64.

What you need

• A PC with a serial port or USB–RS-232 adapter and a null-modem cable to the control's serial connector (usually on the side of the display unit or the control rack — check the machine builder's wiring diagram for which channel is free).
• Terminal / DNC software that can capture and send text files (Cimco Edit, NCnet, TeraTerm all work).
• About 30 minutes of machine downtime. Do this on a healthy machine — not after the alarm appears.

Step 1 — Set the serial port parameters

1. On the control, go to the Data In/Out (I/O) screen and check the port settings: typical values are 9600 baud, 8 data bits, no parity (or 7/even on some builds), 1–2 stop bits, and DC-code (XON/XOFF) handshake. These live in the I/O base parameters (#9001 range).
2. Match your PC software to the same values exactly, and enable XON/XOFF flow control.
3. Select the correct device/channel number on the I/O screen for the port you cabled to.

Step 2 — Back up each data area (control → PC)

On the Data In/Out screen, choose the data type, set the direction to output, start capture on the PC, then press the output (punch) key. Save each area to its own file:

1. Machining programs — select program output, specify ALL (or the full program number range) so every program streams out in one file.
2. Parameters — the critical file. This includes axis, spindle, and machine parameters; without it a replacement CPU or memory board cannot be commissioned.
3. Tool offsets and tool life data.
4. Work offsets (G54–G59) — on most builds these output with the offset data; verify they are in the captured file.
5. Common variables (#100/#500 macro variables) — machines with probing or custom macros keep calibration values here.
6. PLC ladder and PLC data — if the builder's ladder is stored in the NC, output it too. For full PLC work you would use Mitsubishi's GX Developer / PLC onboard tools, but the I/O screen output is enough as a safety copy of PLC parameters and data registers (R/D registers holding ATC tables and machine configuration).

Open every file on the PC and sanity-check it — readable text, sensible length, no truncation. A capture that stops mid-stream usually means a handshake mismatch.

Step 3 — Restore procedure (PC → control)

1. Turn the parameter protect / data protect key OFF (many builders fit a physical keyswitch) and enable parameter writing on the setup screen.
2. On the Data In/Out screen select the data type and set direction to input; the control waits for data.
3. Send the corresponding file from the PC. Restore in this order: parameters first, then power the control OFF/ON, then PLC data, programs, offsets, and common variables.
4. After the restore, the absolute position is normally lost — alarm Z71. Re-initialize the zero point using the same method as on M70/M80 (Absolute Position Setting screen) — our zero point guide walks through it; the M64 screen layout differs slightly but the marked-point logic is identical.
5. Verify soft limits, spindle orientation and tool change position with a careful dry run before cutting.

Common problems

• Nothing outputs / input times out — wrong channel selected on the I/O screen, TX/RX not crossed, or handshake mismatch. Try DC-code handshake and 9600-8-N-1 first.
• Data protect error on input — the protect keyswitch or protect parameter is still active.
• Garbled characters in the capture — baud/parity mismatch, or a cheap USB-serial adapter dropping characters; use an FTDI-based adapter and shorter cable.
• Battery alarm returns after replacement — battery connector or backup circuit on the control board faulty; the SRAM will lose data at the next power-off. Repairable at board level — do not run production without a current backup.

Related guides

• Mitsubishi CNC battery replacement
• Backup guide for the newer M70 / M80
• Mitsubishi alarm list