Recovering an Omron Sysmac C60P Program After Battery Failure

A solid red ALARM LED on a Sysmac C60P in an otherwise-healthy die cutter, paired with a measured backup-battery voltage below 1.0 V, is the classic signature of RAM-retention loss on the C-series family. Because the C**K/C**P generation pre-dates flash-backed user program memory, the ladder program and all retained data words (HR, DM, CNT/TIM PVs) are lost the moment the main supply is removed and the internal lithium cell can no longer hold V_BB. Recovery is possible, but it requires either the original program artifact, an antique programmer, or a full migration to a modern CP1L platform.

This guide consolidates field-proven procedures for the die-cutter service case (Bobst-style / ADC 690 type machines) and applies to any C20P, C28P, C40P, C60P, C20K, C28K, C40K, or C60K that has suffered a similar failure.

1. Problem Description

Reported symptoms on a typical ADC 690 diecutter with a C60P CPU:

• Solid red ALARM LED immediately on power-up; RUN LED does not latch.
• Output modules remain de-energized; machine cannot cycle.
• Onboard lithium cell (3.6 V, ½ AA form factor, typically a Saft LS-14250 or Omron C500-BAT08 equivalent) measures below 1.0 V open-circuit, or below 0.8 V under the 10 kΩ load specified in the C-series service manual.
• Operator display (if equipped) shows error code "BATT" or "P-LOSS" depending on PROM/PROM-converter configuration.

The C60P is the European CE-marked variant of the C-series. The US/Japan domestic equivalent is the C60K. Both share identical firmware, instruction set, and memory map; only the front-panel silkscreen and the AC-input voltage selector differ. When a North American die-cutter OEM ships a machine into the EU, it commonly relabels the C60K as C60P with a 220 V input board.

2. C60P / C60K Memory Architecture

The C-series CPU stores the user program in CMOS static RAM backed by the on-board lithium cell. Unlike later CS1, CJ1, or CP1 families, the C-series has no on-chip flash for the user program. There is no auto-load from EPROM unless the user fitted an optional 3G2A5-MP102B memory pack and set DIP switch SW-2 accordingly.

With the lithium cell depleted, every word in the shaded "retained" rows above reverts to undefined state on the next power-up. The CPU then refuses to enter RUN and latches the red ALARM LED because (a) the program checksum no longer matches the EPROM check, or (b) the DM/HR checksum fails when the optional ROM pack is fitted.

3. Root Cause Analysis

For the C60P platform, the battery-related failure modes rank as follows by frequency in field service data:

1. V_BB open or shorted cell — typical 3.6 V Saft LS-14250 (or generic ½ AA Li-SOCl₂) has reached end-of-life at 15–20 years. Open-circuit voltage below 3.0 V under no load, or below 2.5 V with a 100 kΩ load, indicates end-of-life.
2. CPU detects BATT-LOW — the C60P monitors V_BB through a divider to comparator IC1. When V_BB < 2.7 V the BATT LED is lit and the special relay SR 25308 latches. CPU continues to run; this is a warning, not a fault.
3. Power loss after V_BB collapse — once main 5 V is removed, SRAM contents drift. The next power-up either (a) boots into PROGRAM mode if the program checksum fails, or (b) attempts RUN and immediately re-enters the ALARM state because internal parity detection flags UM corruption.
4. EP-ROM memory pack failure — when an optional 3G2A5-MP102B is installed, the CPU expects the EPROM checksum to match an internal signature. A UV-erased or failed UV-EPROM cell produces the same ALARM but with a different error code on the handheld.
5. External programmer corruption — if the last technician hand-edited a PRO15 and disconnected without saving, a partial program is in SRAM; not a battery issue, but presents identically.

4. Diagnostic Workflow

Follow this ordered procedure before declaring the program lost.

4.1 Battery voltage test

With main power removed, measure the lithium cell at its snap connector on the CPU PCB. The C60P uses a 2-pin JST-style connector; the red lead is V_BB, the black lead is GND. Acceptable thresholds:

4.2 External V_BB injection

If V_BB measures below 2.5 V, perform a "hot swap" backup before any further cycling:

1. Acquire a 3.6 V primary cell matched to the existing chemistry (Saft LS-14250CNA or equivalent). Do not use a rechargeable Li-ion cell — the C-series charges its V_BB from the 5 V rail through a current-limited resistor; an Li-ion would be damaged.
2. Power down the machine. Clip the external cell in parallel with the dead cell using a 2-pin header that mates with the battery clip. Insert a 100 Ω series resistor in the positive lead to limit inrush.
3. Apply main power and read the program back using a PRO15 or SYSWIN session (see §5 and §6). If the PRO15 reads the program and the checksum shows on the display, immediately transfer the program to LSS or a SYM file.
4. Replace the on-board battery with a fresh cell. The C500-BAT08-equivalent replacement has a 5-year shelf life and a 10-year in-circuit life when kept below 45 °C.

5. Recovery Option A — 3G2A6-PRO15 Handheld Programmer

The 3G2A6-PRO15 (also sold as the C120-PRO15) is the original C-series programming console. It connects to the CPU's 25-pin "PERIPHERAL" port and is the only way to read or write the user program when no PC is available.

5.1 Reading the program

1. Set CPU mode switch to PROGRAM. The red ALARM LED may remain lit; that is normal until the program is intact.
2. Plug the PRO15 into the peripheral port. The console should display ** PROGRAMMER **.
3. Press CLR → FUN → 0 → 7 to dump the program checksum. Record the four-digit hex value (e.g., 3F A2).
4. Press CLR → SHIFT → CH → * to begin program listing. Page through the entire program and capture the mnemonics onto paper or photograph the LCD if the unit is the only surviving programmer.
5. Save to cassette using the optional 3G2A5-MP501 cassette interface, or upload to a Windows 9x laptop running SYSMATE.

6. Recovery Option B — SYSWIN + 3G2C7-LK201 Host Link

For a site with a Windows 9x / NT / XP laptop still available, the SYSWIN toolchain offers a more efficient read/write path. SYSWIN version 3.4 is the last release that supports the C**K / C**P CPU family; later versions of CX-Programmer do not include these legacy drivers.

6.1 Cable and host link configuration

The required interface is the 3G2C7-LK201 RS-232C Host Link unit, which installs in the C60P peripheral port slot. Set the LK201 DIP switches to the standard defaults:

Use a straight-through 25-pin male to 9-pin female RS-232 cable (or a 25-to-25 if the laptop has a native DB-25). Modern laptops without a serial port require a USB-to-RS232 adapter based on the FTDI FT232 or an Omron CS1W-CIF31 equivalent; generic Prolific PL2303 chipsets have known timing issues with the C-series and are not recommended.

6.2 SYSWIN upload procedure

1. Set CPU mode switch to PROGRAM.
2. Connect LK201. Power the CPU. Confirm the LK201 PWR and SD/RD LEDs flicker at power-up.
3. Launch SYSWIN 3.4. Choose Communications → Set Up and configure COM1 (or the FTDI virtual COM port), 9600-7-E-1, unit #0, protocol = Host Link.
4. From the PLC → Upload Program menu, save the file as DIE690.LSS. The LSS file is a plain-text mnemonic dump that can be opened in any editor and serves as the canonical archive of the program.
5. Verify the checksum by selecting PLC → Verify Program. The dialog reports OK if the on-CPU checksum matches the uploaded image.

7. Migration Option — CP1L-M60DR-A

If the program cannot be recovered, or the C60P hardware is failing, the most reliable path is a migration to a CP1L-M60DR-A. This 60-IO point CP1L with 60-I/O (36 in / 24 out, relay outputs) is pin-compatible at the CPU footprint only with adapter plates; the wiring side is migrated rung-by-rung.

7.1 I/O address translation

The C-series IR bit addresses translate directly to CP1L CIO bit addresses with the following mapping. The CP1L re-allocates the additional 4 inputs and loses 4 outputs; for a die cutter with 28 outputs this is rarely a problem because solenoid and valve outputs are the lower-numbered group.

Use CX-Programmer's Symbol Type → Address auto-convert to remap these in bulk: IR000 → CIO0, IR004 → CIO100, HR → H, DM → D. The C-series mnemonics LD, AND, OR, OUT, TIM, CNT, SET, RST, CMP, MOV, BCD, BIN, and SFT are CS1-compatible and require no code change.

7.2 Expansion chassis

The C60P supports up to three C-series expansion racks (C500-CE001 chassis), each holding 8 I/O slots. The CP1L-M60DR-A supports up to three CP1W expansion modules in a daisy-chain; each module provides 8, 12, 16, 20, 24, 32, or 40 points depending on catalog code. Field migration typically converts each C500-CE001 slot into one CP1W module on a backplate:

8. Battery Replacement Procedure

For machines that are running but the BATT LED is on, the in-circuit battery swap is a 2-minute job once the cabinet is open:

1. Power the CPU on. Battery-backed SRAM is held by V_BB whenever main 5 V is present, so the battery can be swapped hot only if the CPU stays powered and the new cell is fitted within 30 seconds.
2. Open the C-series CPU's front cover. Locate the 2-pin battery clip.
3. Pinch the connector, not the wire, and pull the dead cell straight out. Do not lever against the PCB.
4. Insert a fresh 3.6 V primary lithium cell of identical form factor (½ AA). Verify polarity: red = +, black = –.
5. Cycle main power. Confirm BATT LED is off and SR 25308 is reset.

Recommended cells: Saft LS-14250CNA (3.6 V, 1.2 Ah), Tadiran TL-5101, or Omron-branded equivalent. Battery life in-circuit at 25 °C ambient is 10 years; at 45 °C it drops to 5 years. Mark the replacement date on the cell with a paint pen and schedule the next swap.

9. Verification

After recovery or migration, run this checklist before returning the die cutter to production.

1. CPU self-test — at power-up, confirm the green POWER LED is on, the red ALARM LED is off, and the RUN LED latches within 2 seconds.
2. Checksum — read the program checksum with the PRO15 or with CX-Programmer (PLC → Compare with Project). It must match the archived LSS file exactly.
3. Force table — exercise every input by hand (limit switches, foot pedal, two-hand control, light curtain). For each input, verify the corresponding IR bit lights in the monitor window. For C60P, the IR bit responds in < 10 ms.
4. Output dry-run — in PROGRAM mode, force each output bit ON. Verify the corresponding solenoid, contactor, or indicator on the machine. Confirm no two outputs are interchanged — a common error when re-wiring from C to CP1L.
5. Single-cycle test — switch to MONITOR mode and run one full sheet through the cutter. Verify the timing chain (feed, gripper, platen, strip) matches the original sequence by reference to the operator's manual cycle chart.
6. Battery alarm — disconnect main 5 V for 60 seconds, restore, and confirm SR 25308 has not latched. This proves the new battery is correctly seated.
7. Archive — back up the program in two locations: the CX-Programmer project on the engineering laptop and an LSS file on a USB drive. Print a hard copy and store it in the machine's documentation drawer.

10. Field-Notes Summary

For a die cutter like the ADC 690, the C60P platform is well past its service horizon. The pragmatic field answer is usually: archive what can be read, then migrate to CP1L-M60DR-A. The CP1L accepts the entire C-series ladder dialect with a one-time address remap, and the controller will outlast any further investment in legacy hardware.

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