Cabling The Cec Drawer, Primary I/O Drawer, And Secondary I/O Drawer(S); Connecting Jtag And V/S Comm Cables; Connecting Rio And Spcn Cables; Rio Cabling - IBM RS/6000 Enterprise Server M80 Service Manual

Cabling the CEC Drawer, Primary I/O Drawer, and Secondary I/O
Drawer(s)
The minimum system consists of two drawers. The CEC drawer contains the system processors, memory
and supporting hardware. The primary I/O drawer contains PCI adapters, operator panel, disk drives, and
media drives. The system must have one primary I/O drawer and it contains the service processor for the
system. The system supports up to three additional I/O drawers in various rack configurations.
To connect the CEC drawer to the I/O drawers, use the following steps:
1. Connect the cables that only connect between the CEC drawer and the primary I/O drawer such as the
JTAG and the V/S COMM cable.
2. Connecting the cables that connect between the CEC drawer and all the I/O drawers in loops, such as
the RIO cables and the SPCN cables.
All power cables connect to the PDU. If a second PDU is specified along with secondary drawer power
supplies for all drawers, the secondary power supplies connect to the secondary PDU.

Connecting JTAG and V/S COMM Cables

Use the following figure to connect the JTAG and V/S COMM cables.
CEC Drawer Attached to One I/O Drawer

Connecting RIO and SPCN Cables

The RIO and SPCN cables provide two functions in the system, remote data bus connection and power
control. Follow these basic rules when connecting these two types of cables:
v The I/O drawers must be connected in a loop fashion for both the RIO cables and the SPCN cables.
The loop connection provides redundant paths so that if a failure occurs in part of a cable, the system
will continue to operate. If a failure occurs, a warning message is displayed on the system console but
the system continues to operate.
v One loop is required for the SPCN cabling. This loop begins and ends at the primary I/O drawer.
v Two loops are possible for the RIO cabling depending on the number and desired configuration of I/O
drawers. These loops begin and end at the primary I/O drawer.

RIO Cabling

The following rules apply to RIO cable connections:
v I/O drawers 0 and 1 are connected using the first RIO loop, which uses RIO ports 0 and 1 on the CEC
drawer.
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Service Guide
CEC Drawer
JTAG V/S COMM
Primary I/O Drawer
JTAG
V/S COMM