FANUC AOA Backup, Image Restore and BMON Workflow: How to Survive a Controller Swap Without Losing the Cell

A controller dies on a Tuesday. The replacement arrives Wednesday. You insert the memory card with the image backup, boot into BMON, choose Restore Image, and the controller refuses. Or it accepts the restore but boots unmastered, with every UFRAME wrong and the vision data missing, and the cell is now a week away from running. This is one of the more painful failure modes in FANUC service, and prevention mostly comes down to taking the right kind of backup before you ever need it.

This post is for maintenance technicians and integrators who own or operate FANUC cells and need to understand the difference between an All of Above (AOA) backup, an image (.IMG) backup and a controlled-start file-level restore, so they can pick the right tool for each scenario. It applies to R-J3, R-J3iB, R-30iA, R-30iB and R-30iB Plus controllers.

How FANUC backups actually work

FANUC has three backup levels, and they are not interchangeable:

• All of Above (AOA) is the everyday backup, taken from the teach pendant’s File menu. It dumps programs (.TP), system variables (.SV), mastering data (stored in SYSMAST.SV), I/O configuration and frames as discrete files onto a USB stick or memory card. It does not save the operating system itself, and it does not save vision data unless you explicitly include it.
• Image backup (.IMG) is a full byte-level image of the controller’s flash memory, taken from BMON (Boot Monitor). It includes the operating system, option files, applications and everything else. It is the closest thing to a clone.
• Controlled Start backup is a finer-grained variant of the AOA, taken with the controller in controlled start, which exposes more system files (such as configuration data that is invisible in normal mode).

Each backup level matches a different restore scenario. An AOA restores into a running controller (you bring a cell back to a known state). An image restores into a target controller (you stand up a replacement). Controlled-start partial restores rebuild specific subsystems when a full image is rejected.

The How to become an expert in one day Reddit thread describes the AOA workflow as the bread and butter of robot maintenance, and rightly so. If you take only one thing from this post, take an AOA backup of every robot you own every quarter.

Most common pitfalls

1. Target controller has a different software version. This is the number one cause of failed image restores. An image taken from a V9.30 controller will not boot on a V9.40 controller, and vice versa. The FANUC R-J3 Frankenstein thread describes mixing and matching R-J3 parts and the option file pain that follows.
2. Image backup taken when the batteries were already failing. If the controller had been throwing BZAL warnings before the backup, the mastering data in the image may already be corrupted. Restoring it gives you a controller that boots but does not move correctly.
3. Memory card not formatted, or too large for older controllers. R-J3 and R-J3iB controllers require specific memory card sizes and formats. A modern 32GB SD card will not boot a 2002-era controller. The Backup image Arc Mate 100iB, R-J3iB thread is the canonical reference: the image backup memory size must match the destination controller.
4. BMON key combination not held long enough during boot. On R-30iB and R-30iB Plus, you press and hold the F1 and F5 keys (or the specific combination for your model) during boot to enter BMON. Release them too early and the controller boots normally. The Fanuc Boot monitor init start up thread walks through this.
5. Option file mismatch. Even with the same software version, two controllers can have different licensed options (vision, EIP, advanced TCP, etc.). An image with vision will fail on a target without the vision option, and vice versa. The import ‘all of above’ in roboguide except DCS thread shows the same fragility: you can selectively restore most things, but DCS in particular resists being moved cleanly.
6. Vision and ladder data not included in the routine backup. Vision data lives in .VD files, ladder in .LDR files. On some firmware versions, the default AOA leaves these out. The Fanuc robot R30iA Ladder PMC symbols, comments and message are not showing in ladder 3 software thread shows what happens when ladder backups are incomplete: symbols and comments are missing after the restore, and an “Add Priority to Memory card data” trick is needed to recover them.

How to set this up correctly (before you need it)

Step 1. Inventory every robot. For each one, record the model, controller generation (R-J3 / R-J3iB / R-30iA / R-30iB / R-30iB Plus), software version (MENU > 4 STATUS > Version ID) and order file or option list. Keep this information somewhere other than the controller you might lose.

Step 2. Take an AOA backup on a fresh USB stick for each robot. From the TP: MENU > FILE > F4 BACKUP > F2 ALL OF ABOVE. Choose USB1: or MC: depending on the hardware. Verify that the backup folder contains SYSMAST.SV (mastering), SYSVARS.SV (system variables), all .TP programs and .SV files and, ideally, vision and ladder files if applicable.

Step 3. Take an image backup at least once after commissioning, and again after any major change (option file change, major program rewrite). Enter the Boot Monitor (BMON) by powering up the controller while holding F1 and F5 on the teach pendant, then choose BACKUP/RESTORE > BACKUP IMAGE. This produces an .IMG file plus several supporting files. Keep them all together.

Step 4. Label the backup with the date, robot serial number, software version and option list. Store at least one copy off-site.

Step 5. For cells with vision, take a separate vision backup. The Back-up USB on Roboguide thread describes the standard workflow, which some users have also applied successfully in RoboGuide; the same .VD files exist on the real controller.

How to do it right when the controller is dead

Scenario A: The replacement controller is an identical clone. Same model, same software version, same options. Insert the memory card, boot into BMON, select Restore Image and confirm. The restore takes about 10 minutes. Cold start afterwards.

Scenario B: The replacement is the same model but runs a different software version. An image restore will likely fail. Instead, controlled-start the new controller with FANUC’s stock OS, then do a file-level restore of SYSMAST.SV, SYSVARS.SV, all .TP programs, the .SV frame files and the .IO configuration. Mastering may need to be re-applied or redone, depending on whether the source SYSMAST.SV is compatible. The Fanuc Boot monitor init start up thread covers the case where a recent “all of above” backup lets you restore everything piece by piece.

Scenario C: The replacement is a different model entirely (e.g., R-J3iB to R-30iB). Do not try to restore the image: the OS architecture is different. Take only the programs (.TP files) and the register and I/O configuration files (.VR, .IO), checking them one by one, and rebuild frames and mastering on the new controller from scratch. Vision and ladder will need to be rebuilt or carefully re-imported.

Scenario D: The image restore is rejected. Fall back to a controlled-start partial restore. Boot the new controller in its default state, do a controlled start, and restore only the files that are universally portable: programs, frames, system variables (with care) and comments. Re-master. Re-apply DCS. This is what the Teach Pendant Black Screen following a cable failure thread recommends when an image restore is not possible.

When to call a specialist

If you have lost the controller and your most recent backup predates a major program change, you are looking at re-teaching positions, which means days of work. A specialist with field experience can usually save the day by working with what is available (program comments, partial backups, the customer’s RoboGuide files). But the time to bring in help is before the restore attempt fails, not after.

For cells where downtime is costly, the right move is to have an image backup verified annually (we take it, then test-restore it into a RoboGuide virtual cell to confirm it boots) and stored off-site. Contact us for an emergency restore, or set up a preventive maintenance contract that includes verified backups twice a year.

Related errors to check

• SYST-212 Need to apply to DCS param: appears after a partial restore if mastering or parameter changes have not been applied to DCS.
• SRVO-062 BZAL: appears if mastering was lost during the controller swap (battery disconnected during the transfer).
• INTP-106 Continue request failed: shows up if the program was restored but the runtime state is inconsistent.
• PRIO-081: option file mismatch after a partial restore.

Probot Systems is a FANUC integrator based in Lévis, Quebec. We handle emergency controller swaps and pre-emptive backup verification for plants across Canada and the US. If you are scoping a controller upgrade or want a verified annual backup routine, that is a conversation worth having: contact us.