Technical data

Chassis Overview
2-5
2
12-slot System
The Model XR9112 12-slot system (see Figure 2-3 on page 2-6) is
designed for telecom applications requiring 12 VME slots and up to
72GB of disk storage capacity.
When support for more than five SCSI devices are required, up to
eight SCSI Device Storage Modules can be added to the system.
Each Storage Module contains up to four half-height drive bays.
Two of these bays can contain removable media devices. The
system can support up to 37 SCSI drives.
The XR Series offers a -48 ±
10% (-36 to -72 with the MC1000K-
DC700A—see Chapter 7) VDC power module for telecom exchange
office applications as well as a 90 to 264 VAC autoranging power
module for industrial and commercial environments. The XR9112
supports either single or dual power module configurations. When
dual power modules are configured, they run in load sharing
mode. In load sharing mode, the system can continue normal
operation if one of the power module fails. For more information
about load sharing, refer to
Load Sharing on page 7-12.
The XR9112 enclosure contains 13 transition module slots for
supporting a variety of connectivity and expansion options, such as
additional Ethernet, SCSI, and communications interfaces.
The XR Series includes a VME module and transition module pair
keying feature which prevents potential module damage caused by
the incorrect insertion of VME or transition modules.