PacComm TINY-2 - Page 124

COMPUTER
INTERFACING
Nonstandard
RS-232C
Serial
Ports
20/pin
4).
You
may
jumper
the
computer's
input
and
output
signals
on
DB-25
pins
4/5
(DE-9
pins
7/8),
and
on
DB-25
pins
6/8/20
(DE-9
pins
6/1/4)
in
addition
to
the
connections
shown
in
the
“3
wire”
RS-232
diagram
above,
or
build
an
‘8
wire”
interface
cable
as
shown
below.
Jumpering
RTS/CTS
and
DTR/DSR/DCD
at
the
Computer
Cabie
End
DB-25:
DE-9:
G
-nnnnne-
5 7
sconen=-
8
6
wne-----
8
weneene-
20
1
--------
ed
6
“Eight-wire”
RS-232
Cabie
Computer
DB-25
or
DE-9
to
TINY-2/MICRO-2
DE-9P
1 ....shell, 5
2
eed
3
3. 2 2
4..
7
7
5
ee
oe
+8
6 eseeere oe 6
7... 5 5
8.
4 1
“connected”
signal
20
4
aeNC
Nonstandard
RS-232C
Serial
Ports
NOTE:
Some
computers
which
require
an
external
TTL
to
iRS-232
adapter
to
support
an
RS-232
serial
port
may
be
linterfaced
to
the
TINY-2/MICRO-2
without
the
RS-232
adapter
junit
by
using
the
TINY-
2/MICRO-2
TTL
level
signals.
Computers
with
nonstandard
RS-232
serial
ports
must
meet
the
following
conditions:
+
Voltage
levels
sent
by
the
computer
must
be
greater
than
+3
volts
j
-3
volts
in
the
other
state.
~
+
The
polarity
of
the
signals
must
conform
to
the
RS-232C
standard,
i.e.
the
low
voltage
state
is
a
logical
“1”
and
the
high
voltage
state
is
a
logical
“0”.
Make
or
buy
a
cable
that
provides
the
following
connections.
+
The
computer
serial
port
common
(ground)
pin
must
be
tied
to
the
TINY-2/MICRO-2
serial
port
connector
pin
5.
+
The
signal
line
that
sends
data
from
the
computer
must
be
tied
to
the
TINY-2/MICRO-2
connector
pin
3.
+
The
pin
on
which
the
computer
receives
data
must
be
tied
to
the
TINY-2/MICRO-2
connector
pin
2.
The
documentation
provided
with
the
computer
or
its
accessory
serial
port
should
clarify
any
requirements
for
additional
signals.
TINY-2/MICRO-2
Technical
Ref.,
2
Ed
©
1989,
PacComm,
Inc.
3