Step 1
Download the trial version of Interarchy from http://nolobe.com/interarchy/
Extract the app, and move to the Applications folder.

Step 2
Open Interarchy, and you will see a window like this:

• In the protocol drop-down, select WebDAV
• In the server, type the IP or hostname you use to connect to your DNS-320
• You can either leave the port as default (80) or change it to 443
• Type in the username and password you have set for webdav access.
• In remote path type: /webdav/YOUR WEBDAV SHARE
• (Where YOUR WEBDAV SHARE is the name/path of the folder you have set as a web-dav share)
• Click List

This will connect you to your DNS-320 via webdav.