Cisco 3000 Series User Manual

Preparing
to Make Connections
Table
2-1
RS-232
Speed
and Distance Limitations
Data Rate Baud Distance
Feet
Distance
Meters
2400 200 60
4800 100 30
9600 50 15
19200 25 7.6
38400 12 3.7
Note RS-232 is often used in violation of these
specifications
if
you
understand the electrical
problems
that
can
arise and can
compensate
for them
you
might
be able to
get good
results at
distances
greater
than those shown in Table
2-1 however
do so at
your
own risk We recommend
that
you stay
within the standard-defined
distance
Interference
Considerations
When
you
run
cables for
any
significant
distance in
an electromagnetic field
interference
can occur
between the field and the
signals
on the cables This fact has two
implications
for the construction
of terminal
plant cabling
Plant
cabling
can emanate radio interference if it is unshielded for too
long
distance
Strong electromagnetic interference
especially
as
caused
by lightning
or
radio
transmitters can
destroy
the RS-232 drivers and receivers in the
server
if
you
use
twisted-pair
cables in
your
plant
cabling
with
good
distribution of
grounding
conductors
the
plant cabling
is
unlikely
to emit radio interference When
exceeding
the distances listed in
Table
2-1 ground
the conductor for each data
signal
If
you
have cables
exceeding
the distances in Table
2-1 or
if
you
have cables that
pass
between
bl4ildings
then
give special
consideration to the effect of
lightning
strikes
or
ground loops
The
electromagnetic pulse
caused
by lightning
or
other
high-energy phenomena
can
easily couple
enough
energy
into unshielded conductors to
destroy
electronic devices If
your
site has
experienced
problems
of this
sort
consult
experts
in
lightning suppression
and
shielding
Most data centers cannot resolve the
infrequent
but
potentially catastrophic problems just
described
without
pulse
meters and other
special equipment
Take
precautions
to avoid these
problems by
providing properly grounded
and shielded
environment
with
special
attention to issues of
electrical
surge
suppression
To
predict
and
remedy
strong electromagnetic interference
consult
experts
in
RFI
2-10 Cisco 3000 Hardware Installation and
Maintenance

Cisco 3000 Series Specifications

General

Model	Cisco 3000 Series
Ports	Varies by model
Switching Capacity	Up to 176 Gbps
Power Supply	Internal or external, varies by model
Layer Support	Layer 2 and Layer 3
Power over Ethernet	PoE or PoE+
Memory	Varies by model
Dimensions	Varies by model
Weight	Varies by model
Operating Temperature	0° to 45°C (32° to 113°F)
Operating Humidity	10% to 85% non-condensing
Uplink Interfaces	Optional 1G/10G SFP/SFP+ or 10GBase-T