1. Open the unit by gently inserting a screw driver between the
DB-25 connector and the lip of the plastic case (see below).
You don’t have to worry about breaking the plastic, but be
careful not to bend the D-sub connector.
Once the unit has been opened, you will be able to see the
terminal blocks located at the rear of the PC board.
2. Strip the outer insulation from the twisted pairs about one inch
from the end.
3. Strip back the insulation on each of the 2 twisted pair wires
about .25”.
When connecting two Model 1020s it is necessary to use a
“crossover” cable. The diagram below shows how a crossover cable
should be constructed for an environment where both Model 1020s 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
‡
The Model 1020 is not sensitive to polarity
Standard AT&T color codes
4.1.2 TWISTED PAIR CONNECTION USING TERMINAL BLOCKS
If your application requires you to connect two pairs of bare wires
to the Model 1020, you will need to open the case to access the
terminal blocks. The instructions on the following pages will tell you
how to open the case, connect the bare wires to the terminal blocks,
and fasten the strain relief collar in place so that the wires won’t pull
loose.
7
8
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