CRS-311 1:1 Redundancy Switch
Revision 7
Serial-based Remote Product Management
MN/CRS311.IOM
6–2
characters.
Control
and
status
information
is
transmitted
in
packets
of
variable
length,
in
accordance
with
the
structure
and
protocol
defined
in
later
sections.
6.2
Interface Overview
6.2.1 EIA-485
For
applications
where
multiple
devices
are
to
be
monitored
and
controlled,
a
full
‐
duplex
(4
‐
wire
plus
ground)
EIA
‐
485
is
preferred.
Half
‐
duplex
(2
‐
wire
plus
ground)
EIA
‐
485
is
possible,
but
is
not
preferred.
In
full
‐
duplex
EIA
‐
485
communication,
there
are
two
separate,
isolated,
independent,
differential
‐
mode
twisted
pairs,
each
handling
serial
data
in
different
directions.
It
is
assumed
that
a
'Controller'
device
(a
PC
or
dumb
terminal)
transmits
data
in
a
broadcast
mode
via
one
of
the
pairs.
Many
'Target'
devices
are
connected
to
this
pair,
and
all
simultaneously
receive
data
from
the
Controller.
The
Controller
is
the
only
device
with
a
line
‐
driver
connected
to
this
pair;
the
Target
devices
have
only
line
‐
receivers
connected.
In
the
other
direction:
On
the
other
pair,
each
Target
has
a
Tri
‐
State
line
driver
connected;
the
Controller
has
a
line
‐
receiver
connected.
All
the
line
drivers
are
held
in
high
‐
impedance
mode
until
one
–
and
only
one
–
Target
transmits
back
to
the
Controller.
Each
Target
has
a
unique
address;
each
time
the
Controller
transmits,
the
address
of
the
intended
recipient
Target
is
included
in
a
framed
'packet'
of
data.
All
of
the
Targets
receive
the
packet,
but
only
one
(the
intended)
will
reply.
The
Target
enables
its
output
line
driver
and
transmits
its
return
data
packet
back
to
the
Controller
in
the
other
direction
on
the
physically
separate
pair.
EIA
‐
485
(full
duplex)
summary:
•
Two
differential
pairs
–
one
pair
for
Controller
‐
to
‐
Target,
one
pair
for
Target
‐
to
‐
Controller.
•
Controller
‐
to
‐
Target
pair
has
one
line
driver
(Controller),
and
all
Targets
have
line
‐
receivers.
•
Target
‐
to
‐
Controller
pair
has
one
line
receiver
(Controller),
and
all
Targets
have
Tri
‐
State
drivers.
Summary of Contents for CRS-311
Page 22: ...CRS 311 1 1 Redundancy Switch Revision 7 Preface MN CRS311 IOM xxii Notes...
Page 48: ...CRS 311 1 1 Redundancy Switch Revision 7 Cables and Connections MN CRS311 IOM 3 2 Notes...
Page 62: ...CRS 311 1 1 Redundancy Switch Revision 7 Cables and Connections MN CRS311 IOM 3 16 Notes...
Page 128: ...CRS 311 1 1 Redundancy Switch Revision 7 Front Panel Operation MN CRS311 IOM 5 20 Notes...
Page 166: ...CRS 311 1 1 Redundancy Switch Revision 7 Appendix A MN CRS311 IOM A 24 Notes...
Page 178: ...CRS 311 1 1 Redundancy Switch Revision 7 Appendix B MN CRS311 IOM B 12 Notes...
Page 186: ...CRS 311 1 1 Redundancy Switch Revision 7 Appendix C MN CRS311 IOM C 8 Notes...
Page 194: ...2114 WEST 7TH STREET TEMPE ARIZONA 85281 USA 480 333 2200 PHONE 480 333 2161 FAX...
