Installation and Configuration of a APC UPS using apcupsd

Installation and Configuration of a APC UPS using apcupsd

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This web-page consists of four sections: Introduction, installation, configuration, and statistics.

1. Introduction

Since one of our machines is configured as print server and because it does other monitoring jobs, I wanted to equip it with an uninterruptable power supply (UPS). Having read already years ago, that there are Linux drivers for UPS's from APC (American Power Conversion) and having seen such a device in an electronics store (Mediamarkt) for Swiss Francs 79.- (about Euro 50.-), I bought the UPS 'APC Back-UPS CS 350 Battery Backup 350'.

2. Installation of Hardware and Software

The installation of the hardware is easy and explained in the manual (and thanks to the company APC there is a printed manual included, not just a CD, which needs a Micro$oft program to read it).
Besides the power cables I also connected the data cable, which on one end (at the UPS) has a RJ-45-like plug and on the other end (at the PC) an USB plug.
Software installation under Debian (Sarge) Linux with Kernel 2.4.26 is easy as well:
apt-get install apcupsd (and answer 'Y' when asked during installation)

3. Configuration of apcupsd

Useful information about the configuration of apcupsd can also be found on http://www.apcupsd.com/ (there, click on 'Online Manual')

Should you have a 2.6 Kernel, such as Kernel 2.6.7 as we use it, you should first do a few steps (if you use a 2.4 kernel, such as kernel 2.4.26, as we did, skip the following lines):
- Add the following line into your /etc/fstab:
none /sys sysfs defaults 0 0
- Then enter mount /sys
- Make sure, the USB subsystem is there and enter ls -l /sys/bus/usb/drivers
- If 'hiddev' is not there, you have a problem. We had this problem as well after having upgraded from a 2.4 to a 2.6 kernel and got an error-message when entering apcaccess. I did two things, which helped to resolve the problem:
- 1. apt-get remove apcupsd followed by a apt-get install apcupsd
- 2. Plug out and plug in again the USB cable on the PC - then things worked fine again!

We continue the description for 2.4 kernels... Now, let's check, whether the connected device was detected:
cat /proc/bus/usb/devices reveals (among many other lines):

T:  Bus=01 Lev=01 Prnt=01 Port=00 Cnt=01 Dev#=  4 Spd=1.5 MxCh= 0
D:  Ver= 1.10 Cls=00(>ifc ) Sub=00 Prot=00 MxPS= 8 #Cfgs=  1
P:  Vendor=051d ProdID=0002 Rev= 1.00
S:  Manufacturer=American Power Conversion
S:  Product=Back-UPS 350 FW: 5.4.I USB FW: c1
S:  SerialNumber=BB0311000473
C:* #Ifs= 1 Cfg#= 1 Atr=a0 MxPwr= 30mA
I:  If#= 0 Alt= 0 #EPs= 1 Cls=03(HID  ) Sub=00 Prot=00 Driver=(none)

Ok, the last line tells us, that there is no driver. We load the driver into the kernel by entering:
modprobe hid and enter again cat /proc/bus/usb/devices; now we see:

T:  Bus=01 Lev=01 Prnt=01 Port=00 Cnt=01 Dev#=  4 Spd=1.5 MxCh= 0
D:  Ver= 1.10 Cls=00(>ifc ) Sub=00 Prot=00 MxPS= 8 #Cfgs=  1
P:  Vendor=051d ProdID=0002 Rev= 1.00
S:  Manufacturer=American Power Conversion
S:  Product=Back-UPS 350 FW: 5.4.I USB FW: c1
S:  SerialNumber=BB0311000473
C:* #Ifs= 1 Cfg#= 1 Atr=a0 MxPwr= 30mA
I:  If#= 0 Alt= 0 #EPs= 1 Cls=03(HID  ) Sub=00 Prot=00 Driver=hid

(With a 2.6 kernel you will see 'Driver=usbhid' on the line above).
So now the driver 'hid' is activated. We can verify this as well by entering
cat /proc/bus/usb/drivers.
In order to have this driver loaded at next boot, we enter two lines in /etc/modules:
# for apcupsd:
hid

The next step is to create appropriate device files. The installation comes with a script, which creates these. Simply enter:
/usr/share/doc/apcupsd/examples/make-hiddev
However, trying to start 'apcupsd' by entering the command:
/etc/init.d/apcupsd start
results in a comment like: "Please check your configuration and then remove this warning to make apcupsd work". In order so follow, what is happening, you should enter (in a separate window) the command:
tail -f /var/log/apcupsd.events and you may watch what is going on.
So we edit the file /etc/init.d/apcupsd and comment the three lines:

##echo -n "Please check your configuration and then remove this"
##echo    " warning to make apcupsd work"
##exit 0

After starting acpupsd again, we get the following message:

Mon Oct 04 03:31:50 CEST 2004  apcupsd FATAL ERROR in smartsetup.c at line 177
PANIC! Cannot communicate with UPS via serial port.
Please make sure the port specified on the DEVICE directive is correct,
and that your cable specification on the UPSCABLE directive is correct.
Mon Oct 04 03:31:50 CEST 2004  apcupsd error shutdown completed

It's time to edit the file /etc/apcupsd/apcupsd.conf and there we read, for USB devices we should set the variable DEVICE as follows:
DEVICE /dev/usb/hiddev[0-15] ... That's wrong! After starting apcupsd we get the message:

Mon Oct 04 14:48:09 CEST 2004  apcupsd FATAL ERROR in smartsetup.c at line 67
Cannot open UPS port /dev/usb/hiddev[0-15]: No such file or directory

Why this? A closer look in /usr/share/doc/apcupsd/examples/make-hiddev gives the explanation: the device files are not created under /dev/usb but under /dev/usb/hid! So we again edit /etc/apcupsd/apcupsd.conf and set:
DEVICE /dev/usb/hid/hiddev[0-15]
But now we get - when starting apcupsd - the following message:

Mon Oct 04 14:50:40 CEST 2004  apcupsd FATAL ERROR in smartsetup.c at line 67
Cannot open UPS port /dev/usb/hid/hiddev[0-15]: No such file or directory

Same error again? Mhh... Maybe, we should modify the cable type in the configuration file; so we edit /etc/apcupsd/apcupsd.conf again and set:
UPSTYPE usb (instead of UPSTYPE smartups) and we enter again:
/etc/init.d/apcupsd start

Now we see in the file /var/log/apcupsd.events that things finally work:
Mon Oct 04 15:02:58 CEST 2004 apcupsd 3.10.15 (04 August 2004) debian startup succeeded
The entries in /etc/apcupsd/apcupsd.conf without the commented lines look as follows:

UPSCABLE smart
UPSTYPE usb
DEVICE /dev/usb/hid/hiddev[0-15]
LOCKFILE /var/lock
ONBATTERYDELAY 6
BATTERYLEVEL 5
MINUTES 3
TIMEOUT 0
ANNOY 300
ANNOYDELAY 60
NOLOGON disable
KILLDELAY 0
NETSERVER on
NISIP 0.0.0.0
NISPORT 3551
EVENTSFILE /var/log/apcupsd.events
EVENTSFILEMAX 10
UPSCLASS standalone
UPSMODE disable
STATTIME 0
STATFILE /var/log/apcupsd.status
LOGSTATS off
DATATIME 0

4. Statistics of apcupsd

We now may run the command apcaccess and view some statistics and information. Among other lines we get the output:

STATUS   : ONLINE
BCHARGE  : 100.0 Percent
TIMELEFT :  43.0 Minutes

However, the number of TIMELEFT is misleading! Let's now plug off the power to the USV and after a minute or plug it in again. We now obtain:

STATUS   : ONBATT
BCHARGE  : 090.0 Percent
TIMELEFT :  11.0 Minutes

which is more realistic, since we have connected to the UPS not only a PC with a Pentium 4, but also a flat screen, an 8-port switch and an ADSL-router. From now on, the UPS reports the correct values.
There are other interesting statistical values given, such as:

TONBATT  : 85 seconds  (while on battery during this power outage, 0 if online)
CUMONBATT: 85 seconds  (cumulative time on battery since start of apcupsd)

And, a power failure produces the following entries in the logfile /var/log/apcupsd.events :

Mon Oct 04 15:28:27 CEST 2004  Power failure.
Mon Oct 04 15:28:33 CEST 2004  Running on UPS batteries.
Mon Oct 04 15:29:58 CEST 2004  Mains returned. No longer on UPS batteries.
Mon Oct 04 15:29:58 CEST 2004  Power is back. UPS running on mains.
Mon Oct 04 15:29:58 CEST 2004  Power failure.
Mon Oct 04 15:29:58 CEST 2004  Power is back. UPS running on mains.

The complete output of the command /sbin/apcaccess is given
in this BigBrother screen.

After having upgraded to kernel 2.6.8 we experienced the following problem:
Entering the command apcaccess (as root) we got the message:
FATAL ERROR in apcaccess.c at line 243
tcp_open: cannot connect to server localhost on port 3551.
ERR=Connection refused

The only thing, which helped, was to unplug the USB-plug at the PC and to
plug it in again. Then I entered:
/etc/init.d/apcupsd restart

From then on things worked fine again!


Last Update: 27Oct2004  uk   -   Created: 04Oct2004


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