Shelf Manager ACB-VI
Redundancy Control
18
R1.2, March 2018
12 Redundancy Control
The Shelf Manager supports redundant operation with automatic switch-over using
redundant Shelf Managers. In a configuration where two Shelf Manager are present, one acts
as the active Shelf Manager and the other as a standby. The Shelf Managers monitor each
other and either can trigger a switchover if necessary.
12.0.1 Hardware Redundancy Interface
The two Shelf Manager communicate over the TCP/IP based Software Redundancy Interface
(SRI) which is implemented via a pair of USB links between the ShMM-700Rs. The active
instance posts incremental state updates to the backup via this interface. As a result, the
backup can quickly step into the active role if necessary.
The Hardware Redundancy Interface (HRI) between the two Shelf Manager instances enables
the exchange of hardware level ShMM-700R state information, including the following:
• Presence: each Shelf Manager instance knows whether the other instance is present in
the shelf.
• Health: each instance knows whether the other instance considers itself „healthy“.
• Switchover: the backup instance can force a switchover if necessary.
The ACB-VI Hardware Redundancy Interface supports the upgrade from ACB-V to ACB-VI in
an ATCA System without interruption. For details see the firmware release notes.
13 Hot Swap Interface
The ACB-VI provides a Hot Swap interface allowing the ACB-VI to be replaced without
powering down the Shelf. The interface is composed of three components:
• Hot Swap switch at injector/ejector handle
• Presence signal indicating that the ACB-VI is fully seated in its
backplane connector
• Hot Swap LED
13.1 Hot Swap LED
The Shelf Manager provides a a blue Hot Swap LED. The LED indicates when it is safe to
"remove" the Shelf Manager from a powered Shelf.
Table 4: Hot Swap LED
LED State
Condition
Off
The Shelf Manager is not ready to be removed from the Shelf
Solid Blue
The Shelf Manager is ready to be removed from the Shelf
Long-blink
The Shelf Manager is activating
Short-blink
Deactivation has been requested