Recovery and Factory Reset

Recovery and Factory Reset#

What to do when the device is in a state you cannot reach from the editor.

Deciding how far to go#

Work down this list. Each step is more disruptive than the one above it.

Symptom

Try

PLC stopped, editor connects fine

Press Play

Program behaving oddly after a change

Clean Upload

Editor cannot find the device

Connect screen, keyboard, and mouse and check network settings on the graphical interface

Editor finds it but cannot connect

Check credentials, then restart the device

Runtime unresponsive

Restart the device

Lost the runtime password

Reset the runtime users

Lost the Linux password

Local console recovery, then reimage

Filesystem corrupted

Reimage

Lost runtime credentials#

The account you created on first connection lives on the device, not in any cloud service, and there is no reset link.

If you still have terminal access, the account database can be cleared on the device. With no accounts present, the next connection from the editor offers Create First User again.

# Stop the runtime
sudo docker stop openplc-bootloader
sudo docker stop openplc-runtime

# Remove the account database
sudo rm /var/lib/openplc-runtime/restapi.db

# Start the runtime again
sudo docker start openplc-bootloader

The runtime recreates an empty database on start. Allow about twenty seconds, then connect from the editor and create a new account.

This clears runtime accounts only

Other data in the same directory is not affected, including retained variables, installed licences, and project_snapshot/, which holds a copy of the original project files stored with every upload and recoverable from the editor.

Take a copy of restapi.db first if you may need to restore it. It can only be restored alongside the .env file that was in place when it was written, since the stored password hashes depend on the secrets that file holds.

Removing /var/lib/openplc-runtime/.env has the same effect. The runtime regenerates the file with new secrets on start, and deletes the account database as part of that, because the existing password hashes cannot be verified against new secrets. Removing restapi.db alone is the narrower operation and is preferred.

If you do not have terminal access, reimage.

Lost Linux credentials#

If you have physical access, connect a monitor and keyboard. A local console session is often enough to recover, and standard Raspberry Pi single-user boot recovery applies.

If you do not have physical access, reimage.

Reimaging#

This is the full reset. It restores the operating system, the OpenPLC runtime, the SPI configuration and the Synergy libraries to their factory state.

It erases everything on the device: your PLC program, runtime user accounts, network configuration, any Python or C++ code you have written, logs, and anything else stored locally.

Before you start#

  • Copy off anything you need, using scp or rsync from your workstation. See Accessing the Device.

  • Confirm you have your project files on your workstation. Every upload also stores a snapshot of the original project files on the device, which the editor can recover, but reimaging erases it.

  • Note the network configuration you will need to restore.

The procedure#

  1. Download the SLM-RP4 image from here.

  2. Download and install Raspberry Pi Imager from raspberrypi.com/software.

  3. Shut the SLM-RP4 down (see Clean shutdown) and disconnect 24 VDC.

  4. Remove the SD card from the SLM-RP4 (see Raspberry Pi status LEDs) and insert it into a card reader on your computer.

  5. Open Raspberry Pi Imager. Under Choose Device, select Raspberry Pi 4.

  6. Under Choose OS, select Use Custom and choose the SLM-RP4 image you downloaded.

  7. Under Choose Storage, select the SD card. Writing erases the selected drive; confirm it is the SD card.

  8. Click Next. When asked whether to apply OS customisation settings, choose No. The image already contains the SLM-RP4 configuration.

  9. Confirm the write and wait for Imager to finish writing and verifying.

  10. Eject the SD card, insert it into the SLM-RP4, and continue with After reimaging.

After reimaging#

  1. Wire and power the device; wait for it to boot.

  2. Confirm it appears in the editor’s Search.

  3. Connect and create the first user again.

  4. Re-apply your network configuration.

  5. Build & Upload your project.

  6. Change the default password. See Accessing the Device.

Backing up#

Preparation makes reimaging considerably faster.

Your PLC project lives on your workstation, in the editor. Put it in version control. The source control features in the editor are the easiest route.

Your Python or C++ code should be in a repository, not only on the device.

Configuration to record:

  • The device’s IP address and how it is assigned

  • The runtime username. Keep the password in a password manager.

  • The backplane arrangement, slot by slot

  • Any HAL settings changed from the defaults

  • Which protocol servers are enabled, and on which ports

Most of that is already in your project file, which is one more reason to keep the project in version control.

Getting help#

If a device is unrecoverable, or the hardware appears faulty rather than misconfigured, contact Synergy Logic.

Have ready the information listed in If the problem persists.