
APC Simple Signalling Daemon (SSD)

Version: 2.0-beta2

May 1999


SSD provides basic shutdown and notification services for systems
powered by an APC UPS in simple signalling mode, using the 940-0020B
interface cable.

For information on installing SSD, see INSTALL. For the impatient, the
basic sequence is:

	# tar xzvf ssd-<version>.tar.gz
	# cd ssd-<version>
	# ./configure
	# make
	# make install
	# vi /etc/ssd.conf
	# cd /
	# /etc/rc.d/init.d/apcssd start

Note that "make install" assumes a SysV-style init rc files
approach. Your mileage may vary. Note that a manual install should be
pretty easy to figure out, just take a look at the Makefile and
apcssd script.

The configuration file (/etc/ssd.conf) contains two lines, one
specifies the port for the UPS. Modify this as needed. The other is
for specifying how long the system will run for once the power
fails. By default, this is 5 minutes (300 seconds). To run as long as
possible (until the battery fully discharges), set this to a large
number.

Scripts are installed by default in /usr/local/share/ssd that provide
the actual notification and shutdown functionality. These may be
modified to provide site-specific functions, or to run commands when
events occur and/or the system shuts down.

Troubleshooting:

Check syslog (/var/log/messages) for errors opening the port. For
Smart-UPS connected via the 940-0020B cable that may have previously
been using the 940-0024C cable in smart mode, the UPS will need to be
placed back into simple mode. To do this, reattach the 940-0024C
cable, and use a terminal program (such as minicom) to communicate
with the UPS. Settings should be 2400 baud, 8 bits, no parity, no
hardware or software flow control. Type the Y character, which should
return "SM". If it does, type the R character (case matters). The UPS
should respond with "BYE". The UPS is now in simple signalling
mode.

For further troubleshooting, SSD can be build in "debug" mode and run
from the command line. Set the AJR_DEBUG symbol using the following
make command in place of the one above:

	# /etc/rc.d/init.d/apcssd stop
	# make CPPFLAGS=-DAJR_DEBUG

SSD can now be run from the command line, will print more diagnostic
messages, and can be run in the debugger to trace down other problems:

	# ./ssd /etc/ssd.conf

or
	# gdb ssd
	...
	(gdb) run /etc/ssd.conf
	...


Carl A. Dunham (cdunham@apcc.com)
American Power Conversion
