CRS-311 1:1 Redundancy Switch
Revision 7
Serial-based Remote Product Management
MN/CRS311.IOM
6–3
6.2.2 EIA-232
This
is
a
much
simpler
configuration
in
which
the
Controller
device
is
connected
directly
to
the
Target
via
a
two
‐
wire
‐
plus
‐
ground
connection.
Controller
‐
to
‐
Target
data
is
carried,
via
EIA
‐
232
electrical
levels,
on
one
conductor,
and
Target
‐
to
‐
Controller
data
is
carried
in
the
other
direction
on
the
other
conductor.
6.2.3 Basic Protocol
Whether
in
EIA
‐
232
or
EIA
‐
485
mode,
all
data
is
transmitted
as
asynchronous
serial
characters,
suitable
for
transmission
and
reception
by
a
UART.
The
asynchronous
character
format
may
be
selected
from
8
‐
N
‐
1
(8
data
bits,
no
parity,
one
stop
bit),
7
‐
E
‐
2
(7
data
bits,
even
parity,
2
stop
bits)
or
7
‐
O
‐
2
(7
data
bits,
odd
parity,
2
stop
bits).
The
baud
rate
may
vary
between
300
and
19,200
baud.
All
data
is
transmitted
in
framed
packets.
The
Controller
is
assumed
a
PC
or
ASCII
dumb
terminal
that
is
in
charge
of
the
process
of
monitor
and
control.
The
Controller
is
the
only
device
that
is
permitted
to
initiate,
at
will,
the
transmission
of
data.
Targets
are
only
permitted
to
transmit
when
they
have
been
specifically
instructed
to
do
so
by
the
Controller.
All
bytes
within
a
packet
are
printable
ASCII
characters,
less
than
ASCII
code
127.
In
this
context,
the
Carriage
Return
and
Line
Feed
characters
are
considered
printable.
All
messages
from
Controller
‐
to
‐
Target
require
a
response,
with
one
exception:
This
will
be
either
to
return
data
that
has
been
requested
by
the
Controller,
or
to
acknowledge
reception
of
an
instruction
to
change
the
configuration
of
the
Target.
The
exception
to
this
is
when
the
Controller
broadcasts
a
message
(such
as
Set
Time/Date)
using
Address
0,
when
the
Target
is
set
to
EIA
‐
485
mode.
6.2.3.1 Rules for Remote Serial Communications with the CRS-311
1.
Always
wait
for
a
response
(or
up
to
15
seconds)
from
the
CRS
‐
311
before
sending
the
next
query
or
command.
2.
If
a
“time
‐
out”
response
(‘~’)
is
sent
from
the
CRS
‐
311,
you
must
resend
the
previous
command.
The
‘~’
response
indicates
that
a
pass
‐
through
command
to
a
modem/transceiver
attached
to
the
CRS
‐
311
has
"timed
‐
out"
and
there
was
no
response
from
the
other
device.
During
this
wait,
do
not
communicate
with
the
CRS
‐
311.
After
the
'~'
response
is
sent
by
the
CRS
‐
311,
it
is
now
ready
to
receive
a
message
again.
The
CRS
‐
311
knows
to
wait
different
times
for
the
different
messages
it
is
sending
to
modems:
Содержание CRS-311
Страница 12: ...CRS 311 1 1 Redundancy Switch Revision 7 Table of Contents MN CRS311 IOM xii This page is intentionally blank...
Страница 22: ...CRS 311 1 1 Redundancy Switch Revision 7 Preface MN CRS311 IOM xxii Notes...
Страница 48: ...CRS 311 1 1 Redundancy Switch Revision 7 Cables and Connections MN CRS311 IOM 3 2 Notes...
Страница 62: ...CRS 311 1 1 Redundancy Switch Revision 7 Cables and Connections MN CRS311 IOM 3 16 Notes...
Страница 108: ...CRS 311 1 1 Redundancy Switch Revision 7 Modem RMI TMI and Switch Configuration MN CRS311 IOM 4 20 Notes...
Страница 128: ...CRS 311 1 1 Redundancy Switch Revision 7 Front Panel Operation MN CRS311 IOM 5 20 Notes...
Страница 166: ...CRS 311 1 1 Redundancy Switch Revision 7 Appendix A MN CRS311 IOM A 24 Notes...
Страница 178: ...CRS 311 1 1 Redundancy Switch Revision 7 Appendix B MN CRS311 IOM B 12 Notes...
Страница 186: ...CRS 311 1 1 Redundancy Switch Revision 7 Appendix C MN CRS311 IOM C 8 Notes...
Страница 194: ...2114 WEST 7TH STREET TEMPE ARIZONA 85281 USA 480 333 2200 PHONE 480 333 2161 FAX...
