9
Switch S3-7: Reset Software Defaults
Switch S3-7 allows the user to reset the software configured facto-
ry defaults.
S3-7
Factory Test
On
Normal Operation
Off
Reset
Switch S3-8: Transmit Data (TD) Sampling Point
Switch 3-8 controls the Transmit Data (TD) sampling point.
S3-8
Setting
Description
On
Normal
TD sampled on the falling
edge of the 1094A Transmit
Clock (TC)
Off
Invert
TD sampled on the rising
edge of the 1094A Transmit
Clock.
10
4
4..0
0 IIN
NS
ST
TA
AL
LL
LA
AT
TIIO
ON
N
Once the Model 1094A is properly configured, it is ready to con-
nect to the twisted pair interface, to the serial port, and to the power
source. This section tells you how to make these connections.
4.1 CONNECTING THE TWISTED PAIR INTERFACE
The Model 1094A supports communication between two DTE
devices at distances to 4 miles (8 km) over 24 AWG (.5mm) twisted
pair wire. There are two essential requirements for installing the Model
1094A:
1. These units work in pairs. Both units at the end of the twisted
pair must have the same 2-Wire connection and DTE rate.
2. To function properly, the Model 1094A needs one
twisted pair of metallic wire. This twisted pair must be
unconditioned, dry, metallic wire, between 19 (.9mm) and 26
AWG (.4mm) (the higher number gauges will limit distance).
Standard dial-up telephone circuits, or leased circuits that run
through signal equalization equipment, or standard, flat modu-
lar telephone type cable, are
not acceptable.
The RJ-45 connector on the Model 1094A’s twisted pair interface is
polarity insensitive and is wired for a two-wire interface. The signal/pin
relationships are shown in Figure 3 below.
Figure 3. Model 1094A twisted pair line interface.
1 (N/C)
2 (N/C)
3 (N/C)
4 (2-Wire TIP)
5 (2-Wire RING)
6 (N/C)
7 (N/C)
8 (N/C)
1
2
3
4
5
6
7
8
NOTE:
Based upon the chosen DTE rate, the Model 1094A
will automatically select the optimum line rate for distance. This
selection is based on the lowest line rate that will support the
DTE rate.
IMPORTANT!:
The Model 1094A has been optimized for
performance at high bitrates (DTE rates greater than 512 kbps).
To ensure accurate performance at these bit rates, please use
twisted pair line interface cable that is at least 330ft (100m) in
length.