From version 0.3, nobody needs to visit the PC to update it. Within about ten minutes of a new release, Nexa offers it to every older gateway when it next calls in (every minute). The gateway downloads it from Nexa, checks it, and installs it silently: the service stops briefly and starts again on the new version. Counters carry on across the restart, so no production count is lost, and unsent data stays in the buffer.

• An update that fails is tried again 6 hours later, never in a loop.
• A gateway is never moved to an older version.
• logs\update.log in the data folder, and one update-<version>.log per release, say what happened.

The service that reads your machines may not install anything. Installing is the job of a separate service, Nexa Edge Update, which only the gateway can start and which runs the installer only when every check passes:

1. The file has the size and SHA-256 that Nexa announced.
2. It carries Nexa’s update signature, made with a key only Nexa holds and checked against the public key built into the gateway. A file changed on the way, or not made by Nexa, is refused.
3. Its version is newer than the one installed.

The gateway reports each step to Nexa (downloading, installing, updated, or failed and why) with its heartbeat.

If your plant must approve every change, untick Install Nexa Edge updates automatically on tab 5. Run (as an administrator). Install new releases yourself from the download page when you are ready; settings and data are kept.

A backup is one .nxedge file holding the settings, the gateway token and passwords, the sending rules and the OPC UA certificate with its key. Restored on this PC or a replacement, it is the same gateway: Nexa knows it, and your OPC UA servers already trust its certificate.

The tag links are not in it, because they live in Nexa; the restored gateway fetches them by itself.

1. On tab 5. Run, as an administrator, click Back up settings….
2. Choose a passphrase of at least 10 characters, and keep it somewhere safe, such as your password manager.
3. Save the file, named nexa-edge-<PC name>-<date>.nxedge, somewhere other than this PC.

1. Install Nexa Edge on the PC, if it is a new one.
2. On tab 5. Run, as an administrator, click Restore settings…, choose the file and type its passphrase.
3. The service picks the restored settings up within seconds. Check the status line reads Running.

Do not run the old and the new PC at the same time: they would send every reading twice. Uninstall Nexa Edge from the old one, or stop its service.