D-Link DNS-327L User Manual page 466

Section 5 - Knowledge Base
Under Mode, select Master from the drop-down list and then
click Add.
Enter the IP address of the other UPS slave on the network.
Click the + button to add more IP addresses.
Make sure the DNS-327L and the UPS slaves are on the same
physical network.
DNS-327L 461
D-Link ShareCenter User Manual