U42093-J-Z716-1-74
Operating Manual
Glossary
SCSI Status
A menu used to show the number, and status, of SCSI devices on the bus.
Shortwave
Lasers or LEDs that emit light with wavelengths around 780 nm or 850 nm.
Short wave lasers are used for FC links up to ~700 m. They are typically
used with multimode fibre. The preferred fibre core size is 50 micron as this
fibre has large bandwidth so that the distance is limited by the fibre attenu-
ation. 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.
SNMP
Simple Network Management Protocol.
Speed
A status type in the FC Status Menu showing the speed (1063 Mbps) of the
FC adapter.
Target
A SCSI device (usually the peripheral) that responds to an operation
requested by a SCSI initiator (usually the host system). SCSI peripherals are
targets, but for some commands (for example, a COPY command), the
peripheral may need to act temporarily as an initiator.
Terminator Block/Termination
An electrical connection at each end of the SCSI bus composed of a set of
resistors (or possibly 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 68-pin high density SCSI
connector on the last SCSI peripheral. If this device is not terminated, data
errors may occur.
