CDM-750 Advanced High-Speed Trunking Modem
Revision 2
Serial-based Remote Product Management
MN-CDM750
7–3
7.3
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.
7.4
Remote Commands and Queries Overview
7.4.1
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
Universal
Asynchronous
Receiver/Transmitter
(UART).
The
asynchronous
character
in
the
form
8
‐
N
‐
1
(8
data
bits,
no
parity,
1
stop
bit).
The
baud
rate
may
vary
from
1200
to
38400
baud.
All
data
is
transmitted
in
framed
packets.
The
Controller
is
in
charge
of
the
process
of
monitor
and
control,
and
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
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.
7.4.2
Packet Structure
The
exchange
of
information
is
transmitted,
Controller
‐
to
‐
Target
and
Target
‐
to
‐
Controller,
in
‘
packets
’.
Each
packet
contains
a
finite
number
of
bytes
consisting
of
printable
ASCII
characters,
excluding
ASCII
code
127
(DELETE).
In
this
context,
the
Carriage
Return
and
Line
Feed
characters
are
considered
printable.
With
one
exception,
all
messages
from
Controller
‐
to
‐
Target
require
a
response
–
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.
Содержание CDM-750
Страница 64: ...CDM 750 Advanced High Speed Trunking Modem Revision 2 Rear Panel Connections MN CDM750 3 20 Notes...
Страница 76: ...CDM 750 Advanced High Speed Trunking Modem Revision 2 Updating Firmware MN CDM750 4 12 Notes...
Страница 142: ...CDM 750 Advanced High Speed Trunking Modem Revision 2 Front Panel Operation MN CDM750 5 66 Notes...
Страница 178: ...CDM 750 Advanced High Speed Trunking Modem Revision 2 Ethernet based Remote Product Management MN CDM750 6 36 Notes...
Страница 224: ...CDM 750 Advanced High Speed Trunking Modem Revision 2 Appendix A MN CDM750 A 4 Notes...
Страница 227: ...CDM 750 Advanced High Speed Trunking Modem Revision 2 Appendix B MN CDM750 B 3 This page is intentionally blank...
Страница 234: ...CDM 750 Advanced High Speed Trunking Modem Revision 2 Appendix B MN CDM750 B 10 Notes...
Страница 256: ...CDM 750 Advanced High Speed Trunking Modem Revision 2 Appendix C MN CDM750 C 22 Notes...
Страница 280: ...CDM 750 Advanced High Speed Trunking Modem Revision 2 Appendix D MN CDM750 D 24 Notes...
Страница 300: ...2114 WEST 7TH STREET TEMPE ARIZONA 85281 USA 480 333 2200 PHONE 480 333 2161 FAX...
