The Reader is only a companion to the Walker. As such, it will only stay awake if it is connected to a Walker. If the connection is lost (eg the Walker turns off), the Reader will turn off too.
Walkers automatically shutdown if the following conditions are all true:
- No tags have been scanned for 20 mins
- No images have been taken for 20 mins
- There are no images awaiting upload
Whether the device is plugged in to power or not doesn't affect the auto shutdown.
Readers will auto power off after 5 seconds if it doesn't find a Walker in pairing mode, or if paired, the Reader will automatically power off when the connected Walker shuts down.