Instruction manual

Operating a Stack of Hubs
4-2 893-839-C
Swapping a Hub in a Stack
To swap a hub in a functioning stack, follow these steps:
1. Disconnect the primary and redundant power cord(s) from the hub
you want to remove.
The other hubs in the stack can be left on and will continue to function.
2. Disconnect the cascade cable from the Cascade Down connector on
the hub above.
3. Disconnect the cascade cable from the Cascade Up connector on the
hub below.
4. Remove the hub (with the attached cascade cables) from the stack.
5. To reconnect the stack without replacing the missing hub, follow
these steps:
a. Connect another cascade cable to the Cascade Down connector on
the hub above the one removed.
b. Connect the other end of the cascade cable to the Cascade Up
connector on the next functioning hub below.
6. To reconnect the stack with a replacement hub, follow these steps:
a. Install the replacement hub.
b. Connect a cascade cable from the Cascade Down connector on the hub
above the replacement hub to the Cascade Up connector on the
replacement hub.
c. Connect another cascade cable from the Cascade Down connector on
the replacement hub to the Cascade Up connector on the next
functioning hub below.
CAUTION: When moving cables between hubs that are powered on, take care
not to touch the cable pins to the hub chassis or to the connector shield.
NOTE: At least one in four hubs in a stack must be on to provide
sufficient power to maintain management and connectivity to the stack.
893-839-CBook Page 2 Thursday, December 12, 1996 4:18 PM