LEGRAND Server Technology PRO3X User Manual page 17

PDU Linking FAQs
What's the difference between a "master unit" and a "link unit"?
Master and link units are the same model PDUs that are equal to each other, and each has its own IP address. You
designate a PDU as the master unit by logging into the unit and then adding a link unit. The first unit becomes the
master, and when the first link unit is added, the master unit is automatically assigned PDU ID "1", which is
reserved to identify a master unit only, and the ID "1" cannot be edited. A connection between the master and
the link unit has now occurred and the chain is formed.
As you continue to add link units to the chain as desired (up to seven link units), you select Link ID "2" through "8"
for the Link ID numbers. (PDU ID "1" was reserved for the master). Notice that the Link ID "2-8" is the sequential
number of each link unit that you select as you add the unit to the chain, and once selected, the Link ID cannot be
edited.
When the chain is established with a single master unit, and one or more link units, communication occurs with
the master unit through its IP address. The master unit, in turn, communicates to the other link units in the chain
through their individual IP addresses, which optimizes power monitoring and PDU management.
Which Server Technology PDUs can be linked?
With network connectivity, the PDU Linking feature supports PRO3X SKUs for Smart, Switched, and Switched
POPS models. Note: All units in the linking chain should be the same PRO3X models.
Can master units be linked together?
No. Once a unit is designated as the master unit in a chain, it cannot be linked to a master unit in another chain. A
master unit can only be linked to one or more link units in a chain.
How many units can be linked?
Including the master, a full chain can include a total of eight units. The first unit added is designated as the master
unit with the ID "1". Each unit you then add to the chain is designated as a link unit, beginning with ID "2" and
ending with ID "8".
What is re-linking?
Re-linking is a required function when a link unit no longer recognizes or responds to the master unit, most likely
caused if the link unit was reset to factory defaults. The status of the disassociated link unit will be displayed as
"Access Denied". Selecting the link unit when in this status displays the Re-link button that allows reconnection of
the link unit in the chain for regaining device control. Note: Re-linking uses the same Link Unit ID and hostname,
but you will need to reauthenticate with your login credentials.
What user privileges are required for managing the PDU Linking configuration?
Administrative privileges are required for both the master unit and link unit. To add a link, your administrative
login account is required, but after that you only log in to the master to manage the chain, as all link units in the
chain are visible in the user interface from the master unit view.
PRO3X User Guide – Features
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