The D-Link DSN-5110-10, DSN-5210-10 and DSN-5410-10 are all primary arrays, each with a single controller board. For High Availability (HA) operation, an additional controller board can be added to each (DSN-510, DSN-520 and DSN-540 respectively).
In order to attach additionalarrays, there are two SAS SFF-8088 connections found on each controller.
The D-Link DSN-5000-10array comes with a single I/O board. For High Availability (HA) operation, an additional I/O board can be added (DSN-500).
For each JBOD expansion array, there are two SAS SFF-8470 connections (which use thumbscrews for locking the cable connector in place) found on each I/O board.
In order to attach the first JBOD expansion array to the primary controller, you will need a SAS SFF-8470 to SFF-8088 cable.
In order to attach an additional JBOD expansion array to the previous JBOD expansion array, you will need a SAS SFF-8470 to SAS SFF-8470 cable.
Please contact your reseller for this cable.