liebert-esp2 - Driver for Liebert UPS, using the ESP-II serial protocol

liebert-esp2 -h

liebert-esp2 -a UPS_NAME [OPTIONS]


This man page only documents the hardware-specific features of the liebert-esp2 driver. For information about the core driver, see nutupsdrv(8).

Be aware that an RS-232 cable with ONLY the RX, TX and ground pin must be used when interfacing with GXT2 series UPS units (and possibly others), since the handshaking lines are used for purposes other than RS-232 flow control.

Use of a standard RS-232 cable with full handshaking may result in undesired operation and/or shutdown. It is therefore advisable to confirm the proper cable/wiring with the diagram provided in the manual with your UPS.

Tested to work on the following units:

•Liebert GXT2-6000RT208

This is an experimental driver. You have been warned.

This driver currently does not support modification of configuration parameters, such as the low battery warning time and automatic restart policy.

This driver supports the following optional settings in ups.conf(5):


Set the speed of the serial connection - 1200, 2400 (default), 4800, 9600 or 19200.

•Richard Gregory <R.Gregory at>
•Arjen de Korte <adkorte-guest at>
•Nash Kaminski <nashkaminski at>


The NUT (Network UPS Tools) home page:

05/20/2024 Network UPS Tools 2.8.2