AHA-F940/F950 Installation Guide
Part Number: 511450-00, Rev. B Page 4 of 8
Print Spec Number: 496519-00
Current Date: 1/22/98
Last Modified: January 22, 1998 11:02 am
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00_B Source Fiels\Production\511450-00B,AHA-
Using Your Fibre
Channel Adapter
Fibre Channel Topologies
Fibre Channel-Arbitrated Loop
The Fibre Channel-Arbitrated Loop (FC-AL) topology allows
you to attach up to 127 nodes without hubs and switches. FC-AL
is a time-shared, full-bandwidth, distributed topology where
each port includes the minimum necessary connection function.
Workstations or servers can be connected to a single disk or a
disk loop with either optical fibre or copper media depending on
the distance requirement. The following figure shows an exam-
ple of this configuration.
Note: Disk drives connected in this configuration
must have an FC-AL interface.
Point-to-Point
The Point-to-Point topology uses Fibre Channel, without the
loop overhead, to increase performance and simplify cabling
between a RAID storage box and a host or multiple hosts. The
following figure shows an example of this configuration.
Troubleshooting Checklist
If you have problems using your host adapter, check these
items first.
nAre all devices powered?
nAre all cables properly connected?
nIs the host adapter firmly seated and secured in the PCI bus
slot?
nDoes your system CMOS setup require you to enable PCI
bus parameters? If so, refer to your computer’s documenta-
tion for instructions. Check that IRQ channel assignment,
board, and BIOS settings have been made.
nSome configuration options apply to a specific PCI bus
slot, so if you change these options be sure you are apply-
ing them to the slot in which the host adapter is installed.
Check your computer documentation to verify which slot
corresponds to which number.
–If there is an interrupt type or interrupt line option in
the setup program, be sure to select Int-A or Interrupt
Type = A. Depending on your system design, you may
also be required to change a motherboard jumper set-
ting.
–If there is a triggering interrupt option, be sure to select
Level.
–If there is an option to enable or disable bus mastering
for the PCI slots, be sure to select Enabled.
–If there is an option to enable or disable individual PCI
slots, be sure the slot in which you install the host
adapter is Enabled.
–If your computer has a combination of ISA (or EISA)
boards and PCI boards, you may need to mark the
IRQs used by ISA/EISA boards as used so the system
BIOS will not try to assign these IRQs to other PCI
boards.
–In some systems the BIOS reserves a set of available
IRQs for PCI boards, and you have to assign these
IRQs manually.
r
Host Worksta-
tion
Fibre Channel
Cable
FC-AL
or
Single FC-AL
Host Worksta-
tion
Fibre Channel
Cable
SCSI
RAID
Control-
SCSI Drives
