User's Manual UPS control system

Q: Does apcupsd support Windows?
A: With release 3.8.0, apcupsd now runs on Win95/98, WinMe, WinNT,
and Win2000 machines. All features of the Unix versions of apcupsd
are implemented. The UPS EEPROM programming features of
apcupsd have not been tested under Windows. Version 3.8.0 does
not support simple signaling UPSes (BackUPS, etc). Version 3.8.1
does support most simple signaling UPSes, but not all cables (due
to deficiencies in the Windows serial port API). Please note that we
have had reports that apcupsd does not work properly on the WinXP
system. If you have any information on this, please email us.
Q: I don’t have a cable, which one should I build?
A: First you must know if you have an apcsmart UPS or a voltage-signalling
UPS. See the table of supported UPSes (see type table). If you
have a apcsmart UPS, we recommend building a Custom Smart (see
Smart-Custom Cable for SmartUPSes) cable. If you have a voltage-
signaling UPS, we recommend that you build a Custom Simple (see
Voltage-Signalling Cable for ”dumb” UPSes) cable.
Q: How much CPU resources does apcupsd use?
A: Depending on your CPU speed, you may see more or less of the CPU
consumed by apcupsd. On a 400MHz Unix system, the CPU usage
should fall well below 0.1%. On slower systems, the percentage will in-
crease proportionally to the decrease in the CPU speed. On a 400Mhz
Win98 machine, the CPU usage will be on the order of 0.5-1.0%. This
is higher than for Unix systems. However, compared to the 30% CPU
usage by APC’s PowerChute (the version on the CDROM shipped
with my UPS), apcupsd’s 0.5-1.0% is very modest.
If you configure apcupsd to run with pthreads (--with-pthreads on
the ./configure line), apcupsd will run considerably faster, otherwise
said, it will consume less of your CPU, and it will use approximately
one third of the memory. For example, Carl Erhorn reports that on
his Solaris system, “With the old 3-process version, we averaged about
4.8MB of total memory used. With the new single process, we use only
about 1.7MB! That’s also a very good improvement.”
Q: What language is apcupsd written in?
A: It is written entirely in C.
Q: We are using apcupsd-3.8.1-1 in RedHat 6.2. The slave, when shutting
down, is reporting an error at line 436 of apcupsd.c. The error is
initiated by apcupsd --killpower! What can we do to fix this, and
is it critical?
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