4.0 INSTALLATION
Once the Model 1040 is properly configured, it is ready to connect
to your system. This section tells you how to connect the Model 1040
to the twisted pair and RS-232 interfaces.
4.1 CONNECTION TO THE TWISTED PAIR INTERFACE
The Model 1040 supports data-only communication between two
RS-232 devices at distances to 12 miles (19.2) and data rates to 38.4
Kbps. There are two essential requirements for installing the Model
1040:
1. These units work in
pairs
. Therefore, you must have one Model
1040 (or a compatible model) at each end of a two twisted pair
interface.
2. To function properly, the Model 1040 needs two twisted pairs of
metallic wire. These pairs must be
unconditioned
, dry, metallic
wire, between 19 and 26 AWG (the higher number gauges may
limit distance somewhat). Standard dial-up telephone circuits or
leased circuits that run through signal equalization equipment are
not acceptable
.
For your convenience, the Model 1040 is available with three
different twisted pair interfaces: RJ-11 jack, RJ-45 jack and terminal
blocks with strain relief.
4.1.1 TWISTED PAIR CONNECTION USING RJ-11 OR RJ-45
The RJ-11 and RJ-45 connectors on the Model 1040's twisted pair
interface are pre-wired for a standard TELCO wiring environment (see
Figure 5). The signal/pin relationships are shown on the table on the
following page.
RJ-1
1
SIGNAL
RJ-45
SIGNAL
1...................GND
†
1 .................N/C
2...................RCV
◊
2 .................GND
†
3...................XMT 3 .................RCV
◊
4...................XMT 4 .................XMT
5...................RCV 5 .................XMT
6...................GND
†
6 .................RCV
7 .................GND
†
8 .................N/C
†
Connection to ground is optional
◊
The Model 1040 is not polarity sensitive
When connecting two Model 1040s, 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 1040s 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 1040 is not sensitive to polarity
4.1.2 TWISTED PAIR CONNECTION USING TERMINAL BLOCKS
If your application requires you to connect two pairs of bare wires
to the Model 1040, you must 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.
9 10
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