Figure 10-4 Scsi Terminator Plug - Silicon Graphics Origin 3900 User Manual

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• Input/output (I/O) module. The I/O module contains two VHDCI connectors and a
switch to set the SCSI ID range. The SGI TP900 storage module supports 1 I/O
module for a 1 x 8 configuration and 2 I/O modules for a 2 x 4 configuration. The
1 x 8 configuration creates a SCSI bus structure with 1 string of 8 drives. The 2 x 4
configuration creates a SCSI bus structure with 2 strings of 4 drives.
Note: When only one I/O module is present in the system, the other I/O module
location contains a loopback module that has no external connectors.
• Loopback module. The backplane of the TP900 consists of two 4-drive channels. A
loopback module is used to connect the two internal drive channels together when
the TP900 is configured as one channel with 8 drives.
• Cooling module. The cooling module consists of fans that pull warm air from a
plenum behind the drive backplane and exhaust the warm air at the rear of the
enclosure. The cooling modules connect to the backplane for power and status
signal connections.
The TP900 system requires one cooling module, which is mounted in the rear of the
system. Optionally, a second cooling module can be added to the system to provide
redundant cooling. In this redundant configuration, the cooling modules operate
together; if one module fails, the other module adequately cools the system until the
faulty unit is replaced.
Note: When you order a TP900 storage module with redundant cooling, it will also
have redundant power (two power supply modules).
• Blank module. Blank modules are placed in all vacant power supply and cooling
module bays to maintain proper airflow through the system.
• Terminator plug. Each I/O module has two 68-pin VHDCI connectors. A host bus
adapter is connected to one of the VHDCI connectors and a terminator plug is
placed in the remaining connector. Figure 10-4 shows the terminator plug.
SCSI Terminator Plug
Figure 10-4
External Components
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