User`s manual
CBI-1010
Cabling
The
CBI-1010
will operate
in
single-ended or differential mode; however,
CMD Technology strongly recommends the use of differential mode
when
the
data transfer rate exceeds five megabytes per second.
If you have no choice
but
to use single-ended mode
at
a high transfer rate, the
SCSI-3
proposal rec-
ommends that the total internal
and
external cable length should be no longer
than
three
(3)
meters
or
9.9
feet
when
the transfer rate is
10
MBytes/second.
Furthermore, the single-ended cable should meet or exceed the following
specifications.
Table
2-5
Cable Specifications
Characteristic Impedance
Signal Attenuation
Pair-to-pair Propagation
Delay Delta
DC Resistance
Termination
No
less
than
90
ohms
and
no
greater
than
140
ohms
.095
dB
maximum
per
meter at 5 MHz
.15
nanoseconds
maximum
per
meter
.23
ohms
maximum
per
meter
at
20
degrees C
The single-ended daughter card adapter for the
CBI-1010
employs active ter-
mination. Some
SCSI
devices still use passive termination, which is inade-
quate at high transfer rates.
If
your system is running
in
single-ended mode at
transfer rates in excess of five megabytes per second
and
the
CBI-1010
is at
one
end
of the
SCSI
bus, you
must
use active termination or some other type
of high-performance termination at the other
end
of the bus.
2-6
Features and Specifications