Disable UPS beeper (USB) in Synology NAS

Small script to disable / enable the beeper sound from a USB connected UPS in Synology DiskStation Manager.

Based on this post from Moshi's Blog.

Some time ago the power went off at 4am for a long time and I had to get up and shutdown the UPS in order to stop the beeping. The abovementioned post describes how to disable it permanently. Still, I did not want it to stop beeping during day time. The next steps and scripts are my solution to disable and enable the beeping during specific parts of the day (in my case between 00h and 09h).

Important: DSM updates seem to remove the scripts under /root/ and rollback the upsd.users file to its original state. If you update DSM you have to repeat the process.

Intro

In most Linux distros there is a set of tools to manage an UPS. Namely:

• upsc - the ups client, which can be used to query details about the ups
• upsd - the service / daemon
• upscmd - command line tool used to send commands and change settings

Some examples:

List available UPSes:

user@nas:/$ upsc -l
ups

List all variables and values from a specific ups:

panda@calvin:/$ upsc ups
battery.charge: 100
battery.type: PbAc
device.mfr: EATON
(...)
ups.beeper.status: enabled
(...)

View a specific field/variable:

panda@calvin:/$ upsc ups ups.beeper.status
enabled

Both upsc and upscmd communicate with the upsd using a client/server model (TCP port 3493). Unfortunately the upsmcd is not available under Synology DiskStation Manager (DSM) OS. Still, we can connect to the upsd using telnet and emulate the commands upscmd would send. The protocol is described here. In our specific case we just want to perform 3 actions (4 messages):

1. Login
   • USERNAME <user>
   • PWD <pwd>
2. Enable or disable the beeper
   • INSTCMD <upsname> <command>
3. Log out
   • LOGOUT

Howto:

1. SSH into the NAS

Activate SSHd under the synology control panel if you haven't done so and SSH into it. Note: under windows you might need a decent console with ssh (git bash?) or to use PuTTY.

ssh <username>@<nas_ip> -p <ssh_port>

2. Find user configuration file

The upsd.users file could be located in two places, find the needed one:

user@nas:/$ find /usr/syno/etc/ups/ /etc/ups/ -name "upsd.users"
(result /path/to/upsd.users)

3. Add a new user to upsd

Edit the upsd.users file (depending on file location according to the previous step) and add a new user account with permissions to change the beeper status

For file inside /usr/syno/etc/ups

user@nas:/$ sudo vim /usr/syno/etc/ups/upsd.users
Password: <insert your pwd>

For file inside /etc/ups

user@nas:/$ sudo vim /etc/ups/upsd.users
Password: <insert your pwd>

Be careful with the VIM editor! In case you are not familiar with it:

• Move the cursor down ↓ until you find the place where you want to add the new lines
• Press I to enter the INSERT MODE
• Edit the file as needed
• Press the Esc Key to leave the edit mode
• Press : to issue a command
• Write "wq" (write an quit) and hit Enter

So, edit the upsd.users file and add a new user with privileges to enable/disable the beeper (replace <upsd_username> and <upsd_pwd> with the desired values):

    [<upsd_username>]
        password = <upsd_pwd>
        actions = SET
        instcmds = beeper.enable beeper.disable ups.beeper.status

4. Restart the upsd service

synoservice --restart ups-usb
(wait a few seconds)

5. Create a python script to issue commands

sudo vim /root/upscmd.py

The upscmd.py script content:

#!/bin/python2
import sys
import telnetlib

user = "<the upsd_username set in upsd.users>"
pwd = "<the upsd_pwd set in upsd.users>"

if len(sys.argv) == 2:
    cmd = sys.argv[1]
else:
    print("the ups command to issue is missing.")
    print("example: upscmd.py beeper.enable")
    exit(1)
    

tn = telnetlib.Telnet("127.0.0.1", 3493)

tn.write("USERNAME {0}\n".format(user))
response = tn.read_until("OK", timeout=2)
print "USERNAME cmd status: {0}".format(response.strip())

tn.write("PASSWORD {0}\n".format(pwd))
response = tn.read_until("OK", timeout=2)
print "PASSWORD cmd status: {0}".format(response.strip())

tn.write("INSTCMD ups {0}\n".format(cmd))
response = tn.read_until("OK", timeout=2)
print "INSTCMD cmd status: {0}".format(response.strip())

tn.write("LOGOUT\n")
print tn.read_all()

Note: You can just clone the repo to a folder in your NAS, edit the file to set the user/pwd and then copy this and the following ups_beeper_control.sh to the right place, e.g.:

sudo cp /volume<N>/<path_to_your_file>/upscmd.py /root/

6. Create a bash script to call the script

Could be skipped or done in a single script. It is used to call the upscmd.py script with "beeper.enable" or "beeper.disable" depending on the time of the day since I want to re-set it not only on specific times (via cron) but also when the NAS boots. See ups_beeper_control.sh.

7. Make the scripts executable

sudo chmod u+x upscmd.py
sudo chmod u+x ups_beeper_control.sh

At this point you can test the scripts:

user@nas:/$ sudo /root/ups_beeper_control.sh disable
Password:
disable beeper...
USERNAME cmd status: OK
PASSWORD cmd status: OK
INSTCMD cmd status: OK

OK Goodbye

Waiting 5 seconds for UPS to update state...
Beeper disabled.

user@nas:/$ sudo /root/ups_beeper_control.sh curtime
Using current time to set UPS beeper status
enable beeper...
USERNAME cmd status: OK
PASSWORD cmd status: OK
INSTCMD cmd status: OK

OK Goodbye

Waiting 5 seconds for UPS to update state...
Beeper enabled.

8. Schedule it

Go to the DSM Web interface (Control panel -> Task scheduler) and add the 3 tasks:

1. Scheduled task to enable beeper (daily)
   • user: root
   • shedule: daily at 9am
   • command: bash /root/ups_beeper_control.sh enable
   • send email when the script terminates abnormally
2. Scheduled task to disable beeper (similar to above)
3. Triggered task to enable / disable on boot based on the current time
   • command: bash /root/ups_beeper_control.sh curtime