The receiver recognizes these special violations and decodes
them as zeros. This method enables the network to meet mini-
mum pulse density requirements. Use HDB3 unless AMI is
required in your application.
Alternate Mark Inversion (AMI)
: AMI defines a pulse as a
“mark,” a binary one, as opposed to a zero. In an E1 Network con-
nection, signals are transmitted as a sequence of ones and zeros.
Ones are sent as pulses, and zeros are sent as spaces, i.e., no
pulse. Every other pulse is inverted from the previous pulse in
polarity, so that the signal can be effectively transmitted. This
means, however, that a long sequence of zeros in the data stream
will cause problems, since the modem receiving the signal relies
on the signal to recover the 2.048 Mbps clock.
If you must use AMI, ensure that the data terminal equipment con-
nected to the unit provides a minimally acceptable pulse density.
For this reason, there are advantages to using HDB3 instead. AMI
coding does not account for ones density. To meet this require-
ment, ensure that the data meets pulse density requirements.
S3
S4
DTE Line Coding
Off
Off
HDB3
Off
On
Internal use only
On
Off
Internal use only
On
On
AMI
Switches S5 through S8: Reserved
Switches S5 through S8 are reserved for future applications and
should be set to OFF.
3.2 CONFIGURE THE REAR INTERFACE CARD
The Model 1186RC has two interface card options: the Model
1001RCM703ST (with ST fiber connector) and 1001RCM703SMA (with
SMA fiber connector). See Figure 4, at upper right. Each of these inter-
face cards support one fiber connector, two BNC and one RJ-48C line
connectors.
The interface card for the Model 1186RC is shipped configured for
use with a BNC connection to the G.703/G.704 Network. If your
Network connection is using BNC, skip this section.
Jumper Configuration
The rear interface card for the Model 1186RC has four internal
jumpers: JP2, JP3, JP4 and JP5. These jumpers are used to match
input/output impedance between the module and external line on the
G.703/G.704 Interface. The jumper settings select either a BNC (75-
ohm) or an RJ-48C (120-ohm) interface. Figure 5 below shows the top
view of the printed circuit board (PCB) and the location of the jumpers.
The following is a description of the jumper settings and the interface
selection:
1. For a 75-ohm connection (BNC/coax), insert all jumpers (default).
2. For a 120-ohm connection (RJ-48C/twisted pair), remove all
jumpers.
8
Figure 5:
Top view of 1186RC circuit board and location of jumpers
Note: Electronic equipment is sensitive to ESD (electrostatic dis-
charge). When you change the internal jumpers on the
1001RCM703XX, use a grounding strap to avoid damages. For more
information call Patton Technical Support (301) 975-1007.
NOTE:
The 1186RC Series rear cards are specifically
designed to operate with the Model 1186RC function card and
must not be swapped with other Patton function cards.
Figure 4:
Interface cards for Model 1186RC.
Model
1000RCM703SMA
Model
1000RCM703ST
RJ-45
TX
RX
JP3
JP2
JP4
JP5
RJ
TX
RX
7
