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apcsmart-old - Man Page

Driver for American Power Conversion Smart Protocol UPS equipment


apcsmart-old -h

apcsmart-old -a UPS_NAME [OPTIONS]


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

Supported Hardware

apcsmart-old should recognize all recent APC models that use a serial protocol at 2400 bps. This is primarily the Smart-UPS, Matrix-UPS and Back-UPS Pro lines.

The driver attempts to support every bell and whistle of the APC reporting interface, whether or not this is strictly sensible.

Some older hardware may only report a handful of variables. This is usually not a bug—they just don’t support anything else.


This driver expects to see a 940-0024C cable or a clone by default. You can switch to the 940-0095B dual-mode cable support with the cable= definition described below.

If your 940-0024C cable is broken or missing, use this diagram to build a clone:


Extra Arguments

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


Configure the serial port for the APC 940-0095B dual-mode cable.


Use shutdown type num, according to this table:


soft shutdown or powerdown, depending on battery status


soft shutdown followed by powerdown


instant power off


power off with grace period


"force OB" hack method for CS 350

Modes 0 and 1 will power up the load when power returns. Modes 2 and 3 will keep the load turned off when the power returns.

Mode 4 exploits an oddity in the CS 350 models since they only seem to support the S command, but then only when running on battery. As a result, the driver will force the UPS to go on battery if necessary before sending the shutdown command. This ensures that the load gets reset.


Some older APC UPS models return bogus data in the status register during a front panel test. This is usually detected and discarded, but some other unexpected values have occasionally slipped through.

APC UPS models with both USB and serial ports require a power cycle when switching from USB communication to serial, and perhaps vice versa.

Authors and History

Nigel Metheringham <Nigel.Metheringham@Intechnology.co.uk> (drawing heavily on the original apcsmart driver by Russell Kroll).

This driver was called newapc for a time and was renamed in the 1.5 series.

In 2.6.2 the driver was renamed to apcsmart-old, being superseded by updated version with new features.

See Also

The core driver


Internet resources

The NUT (Network UPS Tools) home page: https://www.networkupstools.org/

Referenced By

nutupsdrv(8), upsd(8).

07/03/2024 Network UPS Tools 2.8.2. NUT Manual