User's Manual UPS control system

to cause premature shutdowns of the UPS power, we strongly recommend,
especially for voltage- signaling (dumb) UPSes, that you do most of the ini-
tial testing with your computer plugged into the wall rather than your UPS.
Thus if the UPS power is suddenly shut off, your computer will continue
to run. We also recommend using safe-apccontrol as described below, until
you are sure that the signaling is correct.
Also note that if you launch the execution of apcupsd while your voltage-
signaling UPS is on battery power, it is very likely that your UPS will
immediately shut off the power. This is due to the initialization of the serial
port line signals, which often looks to the UPS like a shutdown command.
Finally, double-check the state of your cabling and UPS indicator lights
frequently during testing. For voltage-signaling UPSes, apcupsd is not cur-
rently able to detect whether or not the serial cable is connected. In ad-
dition, some simple signaling UPSes with certain cable combinations are
not able to detect the low battery condition. For more details please see
Voltage Signalling Features Supported by Apcupsd for Various Cables.
Establishing Serial Port Connection
Once you have compiled, installed, and invoked apcupsd, you should wait
to allow apcupsd to configure itself and establish contact with the UPS.
If you see the following message about 30 seconds after starting apcupsd:
apcupsd FATAL ERROR in apcserial.c at line 156
PANIC! Cannot communicate with UPS via serial port.
it means that apcupsd tried for about 30 seconds to establish contact with
the UPS via the serial port, but was unable to do so. Before continuing, you
must correct this problem. Some of the possible sources of the problem are:
• You have not configured the correct serial port name on the DEVICE
directive in your apcupsd configuration file.
• The serial port that you have chosen has logins enabled. You must
disable logins on that port, otherwise, the system prevents apcupsd
from using it. Normally, the file /etc/inittab specifies the ports for
which a getty process is started (on Sun machines, the serial port
program equivalent to getty is called ttymon). You must disable this
for the port that you wish to use.
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