Fanuc 10 / 11 / 12 Series Backup & Restore Procedure — Parameters, Programs, Offsets via RS-232

Fanuc 10, 11 and 12 series controls (10T/10M, 11T/11M, 12M — built roughly 1983–1990) store everything in battery-backed memory and, on many units, bubble memory cassettes. There is no memory card slot and no USB: the only way in or out is the RS-232 (serial) port. If your machine still runs on one of these controls, a current backup is the difference between a 30-minute battery change and weeks of hunting for a parameter printout from 1987. Here is the complete backup and restore procedure.

What you need

• A laptop with a serial port or a USB–RS-232 adapter (FTDI chipset recommended), plus a null-modem cable to the control's 25-pin punch/read connector.
• DNC / terminal software that can capture and send text files (NCnet, Cimco Edit, DNC4U, even TeraTerm).
• The communication settings from the control (below) — both sides must match exactly.

Step 1 — Set the communication parameters

1. On the control, check the I/O parameters (on 10/11 series these are in the 5000–5100 range; typical setup: device = RS-232, baud rate 4800, 7 data bits, even parity, 2 stop bits, ISO code).
2. Set your PC software to the same values. Start with 4800 baud — faster rates are unreliable over long cables on these controls.
3. Enable XON/XOFF (DC1–DC4) flow control on the PC side; the control uses DC codes to start and stop the punch stream.

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

Start the capture in your PC software first, then command the output on the control. Repeat per area, saving each to its own clearly named file:

1. Part programs: EDIT mode → select program screen → key in O-9999 (all programs) → press PUNCH. All programs stream out as one file.
2. CNC parameters: set parameter write enable (PWE = 1 on the setting screen), open the parameter screen and press PUNCH. This is the most important file of all — without it a replacement board is a brick.
3. Pitch error compensation: from the pitch error screen, PUNCH the same way.
4. Tool offsets / work offsets: from the offset screen → PUNCH.
5. Custom macro variables (if the machine uses macro programs for probing or tool life): punch the macro variable screen output as well.
6. PMC ladder and PMC parameters (counters, keep relays, data tables): from the PMC screen → I/O → punch to RS-232. Keep relays and data tables hold machine-specific settings (tool pot tables, ATC counts) that you cannot reconstruct from memory.

Open every captured file in a text editor and check it: it should start with %, contain readable ISO text, and end with %. A zero-byte or garbage file means a settings mismatch — fix it now, not the day the memory dies.

Step 3 — Restore procedure (PC → control)

1. Put the control in EDIT mode. For parameters, first set PWE = 1; the control will alarm (100) — normal.
2. On the relevant screen (program / parameter / offset / pitch error), press READ (INPUT) so the control waits for data.
3. Send the file from the PC. On these controls, always send with a short leading delay and XON/XOFF enabled.
4. After parameters are loaded, set PWE = 0 and power the control OFF/ON.
5. Load PMC keep relays / data tables from the PMC I/O screen the same way, then restore programs and offsets.
6. After a full restore, re-establish the machine reference position — see our absolute referencing guide — and verify soft limits, then dry-run a known program above the work.

Common problems

• Nothing comes out on PUNCH — wrong I/O channel selected in parameters, or TX/RX not crossed (use a null-modem cable, pins 2–3 crossed, or a proper Fanuc punch cable).
• Alarm 85/86/87 during READ — serial framing/overrun errors: baud rate, parity or stop bits mismatch, or cable too long/noisy. Drop to 2400 baud and retry.
• File loads but machine behaves wrong — PMC keep relays / data tables not restored; load them from the PMC screen.
• Bubble memory alarm at power-up (e.g. 910-series memory alarms) — the bubble cassette or memory board is failing. Do not keep power-cycling; each attempt risks the remaining data. If the control still boots, back up everything immediately, then have the board repaired.

Related guides

• How to replace a Fanuc CNC battery
• Backup guide for the newer 0i/16i/18i/30i series
• Fanuc Series 0 absolute referencing procedure