This man page only documents the hardware-specific features of the liebert driver. For information about the core driver, see nutupsdrv(8).
This driver supports some Liebert UPS equipment with a contact-closure interface. This includes the UPStation GXT2 with their contact-closure cable. The smart mode ("Multilink") cable is not supported by this driver.
This driver does not support any extra settings in the ups.conf(5).
This driver does not yet support shutdowns by raising DTR. Be aware that shutdowns are not possible with the stock contact-closure cable. You may have to build another cable with DTR connected through to the UPS for it to work.
There is no way for this driver to detect the hardware or cable. It will start up successfully even if no UPS is present. This is a fundamental limitation of any contact-closure driver.
The core driver
The NUT (Network UPS Tools) home page: https://www.networkupstools.org/