bmspy-ups selected its device from the devices that had data at startup, and exited with status 0 if the selection failed. One failed first read ended the monitor or made it select the wrong device.
The server has a new DEVICES command that lists the configured names, and client.list_devices calls it. bmspy-ups selects from that list and then waits for the first data of its device. A wrong or missing --device now exits with status 2. The service file does not restart on that status, because a restart cannot correct it.
An older server ends on the unknown DEVICES command, so update the server first.
tim
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