When connecting two Model 1035s, it is necessary to use a twisted
pair “crossover” cable. The diagram below shows how a crossover
cable should be constructed for an environment where both Model
1035s use a 6-wire RJ-11 connector. Similar logic should be followed
when using RJ-45 connectors or a combination of the two.
SIGNAL
PIN#
COLOR
‡
COLOR
PIN#
SIGNAL
GND
†
1
Blue .................White
6
GND
†
RCV
2
Yellow ..............Red
4
XMT
XMT
3
Green...............Black
5
RCV
XMT
4
Red ..................Yellow
2
RCV
RCV
5
Black ................Green
3
XMT
GND
†
6
White ...............Blue
1
GND
†
†
Connection to ground is optional
‡
Standard color codes—yours may be different
4.2 CONNECTION TO THE RS-232 AND V. 35 INTERFACES
Once you have connected the twisted pair wires correctly, simply
plug the Model 1035 directly into the DB-25 port of the RS-232 or V.35
device. After doing so, remember to insert and tighten the two captive
connector screws.
4.2.1 CONNECTION TO A “DTE” DEVICE
The Model 1035 is wired as a DCE, and therefore “wants” to plug
into a DTE such as a terminal, PC or host. A direct connection to the
RS-232 or V.35 DTE port is most desirable. If you must use a cable to
connect the Model 1035 to the DTE port, make sure it is a
straight
through
cable of the shortest possible length—we recommend 6 feet or
less.
9
Figure 5. Standard AT&T color codes
1 - Blue
2 - Yellow
3 - Green
4 - Red
5 - Black
6 - White
1 - Blue
2 - Orange
3 - Black
4 - Red
5 - Green
6 - Yellow
7 - Brown
8 - Slate
4.2.2 CONNECTION TO AN RS-232 “DCE” DEVICE
Since the Model 1035 is wired as a DCE, you cannot connect it
directly to another DCE such as a modem, multiplexer or printer. If you
need to connect the Model 1035 to another RS-232 DCE device, you
must use a
null modem cable
wired according to diagram below. We
recommend a cable of the shortest possible length, preferably 6 feet or
less.
Connection to Model 1035
†
Connection to DCE Device
DB-25 Pin No.
DB-25 Pin No.
1 .....................................................1
2 .....................................................3
3 .....................................................2
4 .....................................................8
8 .....................................................4
6 ...................................................20
20 .....................................................6
17 ...................................................24
24 ...................................................17
7 .....................................................7
†
Note: When connected to another DCE device, the Model 1035
should be configured for “external clock” (see Section 3.3).
4.2.3 CONNECTION TO A V.35 “DCE” DEVICE
For details on connecting the Model 1035 to a V.35 DCE, please
contact Patton Electronics Technical Support at (301) 975-1007.
10