Mac Forum / General / Hardware / October 2004

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That is not a mount point.  /dev/usb/... are special filesystem nodes
that correspond with block devices.  You do not want to mount this
device anywhere (especially on it's block control device node), but have
the ups daemon monitor this device node that corresponds to the UPS
device.  Communication is done through this port, and both the daemon
and the UPS have to speak the same language once the connection is sound.

Take a look at the NUT documentation.  The ups.conf takes a "port="
config.  Often this port is a serial port, which is likely to work on a
wider variety of systems.  OS X handles USB access via USB Device
Arbitration mechanisms, some of which require a kernel extension.  That
is, there is no simple Unix block device representing the various USB
devices that OS X can handle.

A look at http://us1.networkupstools.org/compat/ indicates that NUT does
not have tested support for "Energizer" products.  It may work with the
serial port (if you are lucky) with existing drivers.  However, it may
be that the NUT project needs someone to support this hardware explicitly.

Heck, some UPS devices even need special cables to work with alternate
systems.

My advice: get a UPS device that works with OS X out of the box, or
review the supported NUT configs and get hardware that is known to work
with that.  Assume a sort of FreeBSD system for OS X, which implies
getting a device that talks via the serial port.  This can be a problem
for OS X, obviously, so caveat emptor.

Another solution might be to have an edge or server box that _can_ talk
to a UPS device send network traffic to a listening daemon on your OS X
machine(s) to tell it/them to shut down gracefully.