I managed to find our that the EX2 is using NUT aka Network UPS Tools, a standard Linux service to monitor UPS. It consists of a client and a server component and uses tcp connections on port 3493.
You can see it running on the EX2:
root@MyCloudEX2Ultra etc # netstat -tulpn | grep ups
tcp 0 0 127.0.0.1:3493 0.0.0.0:* LISTEN 6876/upsd
tcp 0 0 172.17.42.1:3493 0.0.0.0:* LISTEN 6876/upsd
The config resides in /usr/local/ups/etc.
The file upsd.users shows, that a remote user named “client” can connect using the password “123”.
The system’s local usb-connected ups is called usbhid, as one can see in ups.conf.
On a remote system you need to install nut (apt install nut nut-client) and adjust the file upsmon.conf.
An example entry would look like this:
MONITOR usbhid@MyCloudEX2 1 client 123 slave
I got a debian machine as well as a Synology running DSM connect as ups-clients to the EX2.
On Synology one needs to edit /usr/syno/etc/ups/upsmon.conf and edit the line
MONITOR ups@your-remote-hosts-ip 1 monuser secret slave
so that monuser will be changed to client and secret to 123.
You must restart the ups service afterwards.
This is a little tricky as dsm tends to overwrite it after reboot or using the dsm-webinterface.
One coud try to create a script /volume1/homes/admin/syno_scripts/upsmon-add-mycould.sh and execute it after boot with the following contents:
sed -i – ‘s/monuser secret/client 123/g’ /usr/syno/etc/ups/upsmon.conf
sed -i – ‘s/ups@/ushid@/g’ /usr/syno/etc/ups/upsmon.conf
synoservice --reload ups-net
It might be easier to add the user “monuser” with password “secret” on your EX2, see this tutorial.
Basially you just have to add this:
password = secret
Under any circumstances you must make the configuration changes permanent, otherwise they will get lost after a reboot.