SCSI addressing

A SCSI adapter supports up to 16 devices, including itself. Each device has its own unique

 

SCSI address. The SCSI address of a device dictates the device’s priority when arbitrating for

 

the SCSI bus. SCSI address “7” has the highest priority. The next highest priority address is

 

“6” followed by 5, 4, 3, 2, 1, 0, 15, 14, 13, 12, 11, 10, 9, 8, with “8” being the lowest

 

priority address.

 

The narrow SCSI adapter is factory set to address 7. A narrow SCSI adapter supports up to

 

eight devices, including itself. SCSI address “7” has the highest priority followed by 6, 5, 4, 3,

 

2, 1, and 0.

SCSI bus

The means of transferring SCSI data between SCSI devices. It is an 8-bit or 16-bit bus that

 

supports up to eight or sixteen devices (including itself), in any mix of initiators and targets, with

 

the limitation that at least one initiator and one target must be present.

SCSI device

A single unit on the SCSI bus, identifiable by a unique SCSI address. A SCSI device can act as

 

an initiator or target. For SCSI-3, each SCSI device supports up to sixteen LUNs.

SCSI port

An opening at the back of the interface card providing connection between the SCSI adapter

 

and the SCSI bus.

SCSI status

A menu name used to show the number of SCSI devices on the bus.

small formfactor

A physical component that manages the functions of the FC-0 layer, which is the physical

pluggable (SFP)

characteristic of the media and interface, including drivers, transceivers, connectors, and

 

cables. Mounts on a FC adapter card and connects the interface card to a FC host.

shortwave

Lasers or LEDs that emit light with wavelengths around 780 nm or 850 nm. When using

 

multimode fibre (50 nm), shortwave lasers can be used with FC links less than 500m. To

 

achieve longer lengths, single-mode fibre is required. The preferred fibre core size is 50 micron

 

as this fibre has large bandwidth so that the distance is limited by the fibre attenuation. A

 

62.5 micron core size is also supported for compatibility with existing FDDI installations. Fibre

 

of this type has smaller bandwidth and, in this case, the distance is limited by the fibre

 

bandwidth.

speed

A status type in the FC Status Menu showing the speed (1063 Mbps) of the FC adapter.

switched fabric

A FC term describing a switched topology, which is one of the three existing FC topologies.

 

Fabric elements interconnect various N_Ports or NL_Ports and are responsible for frame routing.

TCP

Transmission Control Protocol

target

A device (usually a peripheral) that responds to an operation requested by an initiator (usually

 

a host system). Peripherals are targets, but for some commands (for example, a SCSI COPY

 

command), the peripheral may need to act temporarily as an initiator.

terminator

An electrical connection at each end of the SCSI bus composed of a set of resistors (or possibly

block/termination

other components). Its function is to provide a pull-up for open collector drivers on the bus, and

 

also impedance matching to prevent signal reflections at the ends of the cable.

 

The SCSI bus requires termination at both ends of the bus. One end of the SCSI bus is

 

terminated by the SCSI adapter’s internal termination. The other end should have a terminator

 

placed on the SCSI connector on the last SCSI peripheral. If this device is not terminated, data

 

errors may occur.

topology

The physical or logical layout of nodes on a network. FC topologies include Point-to-Point,

 

FC-AL, and Fabric.

view node name

A status type in the FC Status Menu showing the identification of the node.