Patton electronics NetLink 2720/B User manual

USER
MANUAL
MODEL 2720/B and 2720/C
Series
NetLink-T1™
T1/Fractional T1 CSU/DSU
SALES OFFICE
[phone]
TECHNICAL SUPPORT
[phone]
http://www.patton.com
Part# 07M2720-UM
Doc# 08615U2-001,
Rev. B
Revised 10/26/06
An ISO-9001
Certified Company

12
TABLE OF CONTENTS
Section Page
1.0 Warranty Information.............................................................2
1.1 Warranty Statement
1.2 Radio and TV Interference
1.3 Industry Canada Notice
1.4 FCC ComplianceStatement
1.5 Service Information
1.6 CE Notice
2.0 General Information...............................................................5
2.1 Features
2.2 General Product Description
3.0 Configuration .........................................................................6
3.1 DIP Switch Configuration
3.2 Software Configuration
4.0 Installation ..........................................................................32
4.1 DTE Interface Connection
4.2 Network Interface Connection
4.3 DC Power Supply
5.0 Operation.............................................................................33
5.1 LED Descriptions
5.2 Loop (V.54 & Telco) Diagnostics
5.3 Bit Error Rate (V.52) Diagnostics
Appendix A - Specifications ........................................................39
Appendix B - Cable Recommendations......................................40
Appendix C - Factory Replacement Parts and Accessories ......41
Appendix D - T1 Interface Pin Assignments ..............................42
Appendix E - DTE Interface Pin Assignments............................44
1.0 WARRANTY INFORMATION
Thank you for your purchase of this Patton Electronics product. This
product has been thoroughly inspected and tested and is warranted for One
Year parts and labor. If any questions or problems arise during installation
or use of this product, please do not hesitate to contact Patton Electronics
Technical Support at [phone].
1.1 WARRANTY STATEMENT
Patton Electronics warrants all Model 2720 Series components to be
free from defects, and will—at our option—repair or replace the product
should it fail within one year from the first date of shipment. This warranty is
limited to defects in workmanship or materials, and does not cover cus-
tomer damage, abuse, or unauthorized modification. This product contains
no serviceable parts; therefore you should not attempt to modify the unit in
any way. If this product fails or does not perform as warranted, your sole
recourse shall be repair or replacement as described above. Under no con-
dition shall Patton Electronics be liable for any damages incurred by the
use of this product. These damages include, but are not limited to, the fol-
lowing: lost profits, lost savings and incidental or consequential damages
arising from the use of or inability to use this product. Patton Electronics
specifically disclaims all other warranties, expressed or implied, and the
installation or use of this product shall be deemed an acceptance of these
terms. In the event that you detect intermittent or continuous product mal-
function due to nearby high power transmitting radio frequency equipment,
use only data cables with an external outer shield bonded to a metal or
metalized connector.
1.2 RADIO AND TV INTERFERENCE
The NetLink-T1™ Model 2720 Series generates and uses radio fre-
quency energy, and if not installed and used properly—that is, in strict
accordance with the manufacturer's instructions—may cause interference to
radio and television reception. The Model 2720 Series has been tested and
found to comply with the limits for a Class A computing device in accor-
dance with the specifications in Subpart J of Part 15 of FCC rules, which
are designed to provide reasonable protection from such interference in a
commercial installation. However, there is no guarantee that interference
will not occur in a particular installation. If the Model 2720 Series causes
interference to radio or television reception, which can be determined by
disconnecting the cables, try to correct the interference by one or more of
the following measures: moving the computing equipment away from the
receiver, re-orienting the receiving antenna, and/or plugging the receiving
equipment into a different AC outlet (such that the computing equipment
and receiver are on different branches).
WARNING! This device is not intended to be con-
nected to the public telephone network in Europe.

43
1.3 INDUSTRY CANADA NOTICE
The Canadian Department of Communications label identifies cer-
tified equipment. This certification means that the equipment meets
certain telecommunications network protective, operational and safety
requirements. The Department does not guarantee the equipment will
operate to the user's satisfaction. Before installing this equipment,
users should ensure that it is permissible to be connected to the facili-
ties of the local telecommunications company. The equipment must
also be installed using an acceptable method of connection. In some
cases, the company’s inside wiring associated with a single line individ-
ual service may be extended by means of a certified connector assem-
bly (telephone extension cord). The customer should be aware that
compliance with the above condition may not prevent degradation of
service in some situations. Repairs to some certified equipment should
be made by an authorized maintenance facility designated by the sup-
plier. Any repairs or alterations made by the user to this equipment, or
equipment malfunctions, may give the telecommunications company
cause to request the user to disconnect the equipment. Users should
ensure for their own protection that the ground connections of the
power utility, telephone lines and internal metallic water pipe system,
are connected together. This protection may be particularly important
in rural areas.
1.4 FCC PART 68 COMPLIANCE STATEMENT
This equipment complies with Part 68 of FCC Rules. Please note the
following:
1. You are required to request service from the telephone company
before you connnect the CSU to a network. When you request serv-
ice, you must provide the telephone company with the following data.
When you request T1 Service, you must provide the telephone compa-
ny with the Facility Interface Code. Provide the telephone company
with both of the following codes: 04DU9-B (1.544 MB D4 framing for-
mat) and 04DU9-C (1.544 MB ESF format). The telephone company
will select the code it has available. The Service Order Code(s) (SOC):
6.0N. The required Universal Service Order Code (USOC) jack: RJ
48C. The make, model number, and FCC Registration number of the
CSU.
2. Your telephone company may make changes to its facilities, equip-
ment, operations, or procedures that could affect the proper functioning
of your equipment. The telephone company will notify you in advance
of such changes to give you and opportunity to maintain uninterrupted
telephone service.
3. If your CSU causes harm to the telephone network, the telephone
company may temporarily discontinue your service. If possible, they
will notify you in advance, but if advance notice is not practical, you will
be notified as soon as possible and will be informed of your right to file
a complaint with the FCC.
4. If you experience trouble with the CSU, please contact Patton
Electronics, Co. for service or repairs. Repairs should be performed
only by Patton Electronics Co.
5. You are required to notify the telephone company when you dis-
connect the CSU from the network.
1.5 SERVICE INFORMATION
All warranty and non-warranty repairs must be returned freight
prepaid and insured to Patton Electronics. All returns must have a
Return Materials Authorization number on the outside of the shipping
container. This number may be obtained from Patton Electronics
Technical Support at: tel: [phone] email:
[email protected] www: http://www.patton.com.
NOTE: Packages received without an RMA number will not be accept-
ed. Patton Electronics' technical staff is also available to answer any
questions that might arise concerning the installation or use of your
Patton Model 2710RC. Technical Support hours: 8AM to 5PM EST,
Monday through Friday.
1.6 CE NOTICE
The CE symbol on your Patton Electronics equipment indicates
that it is in compliance with the Electromagnetic Compatibility (EMC)
directive and the Low Voltage Directive (LVD) of the European Union
(EU). A Certificate of Compliance is available by contacting Technical
Support.
CAUTION: Users should not attempt to make such connections
themselves, but should contact the appropriate electric inspection
authority, or electrician, as appropriate.
Facility
Interface Service Network
Service Code Code Connection
1.544 Mbps SF format without line power 04DU9-BN 6.0N RJ48C
1.544 Mbps SF and B8ZS without line power 04DU9-DN 6.0N RJ48C
1.544 Mbps ANSI ESF without line power 04DU9-1KN 6.0N RJ48C
1.544 Mbps ANSI ESF and B8ZS w/o line power 04DU9-1SN 6.0N RJ48C

56
3.0 CONFIGURATION
The Model 2720 features configuration capability via hardware
DIP switches or a software control port. This section describes all pos-
sible hardware and software switch configurations of the NetLink-T1™.
3.1 DIP SWITCH CONFIGURATION
The Model 2720 has two eight bit DIP switches that allow configu-
ration for a wide range of applications. The switches are externally
accessable by removing the plate on the bottom side of the unit.
Figure 1 (below) shows the location of the DIP switches on the bottom
of the printed circuit board.
DIP Switches S1 and S2 can be configured as either “On” or “Off”.
Figure 2 (below) shows the orientation of the DIP switches with respect
to ON/OFF positions. Default position and descriptions for Switches
S1 and S2 are provided on pages 6-10.
2.0 GENERAL INFORMATION
Thank you for your purchase of this Patton Electronics product. This
product has been thoroughly inspected and tested and is warranted for One
Year parts and labor. If any questions arise during installation or use of the
unit, contact Patton Electronics Technical Services at [phone].
2.1 FEATURES
• Terminates T1/FT1 Circuits over a 4-Wire RJ-48C interface
• Connects to standard CPE Serial Interfaces
• Common Framed nx56/64 rates up to 1.536 Mbps
• Unstructured Rates at 1.544 Mbps
• D4 or ESF Framing Modes
• Supports AMI or B8ZS/B7ZS Line Coding
• Configuration via Software Control Port or Internal DIP Switches
• Six Easy-to-Read LED Indicators Monitor Data & Diagnostics
• Internal, External or Network Clocking
• Also Operates as a High-Speed Point-to-Point Modem
• Made in USA
2.2 GENERAL PRODUCT DESCRIPTION
The NetLink-T1™ Model 2720 Series are single port T1/FT1
CSU/DSUs that provide high-speed WAN connectivity. Plugging directly into
the serial WAN port of a switch, router or multiplexer, the NetLink-T1™ pro-
vides T1 or FT1 access at connection data rates of 1.544 Mbps, nx64, and
nx56 (n=1 to 24 channels). The Netlink-T1™ is an excellent choice when
terminating leased line services, Frame Relay backbones, internet access
as well as LAN-to-LAN services.
The Netlink-T1™ provides digital access to a local WAN service
provider or directly between two facilities over a dedicated 4-Wire circuit.
WAN bandwidth, framing and coding options are programmed via externally
accessible DIP switches or via a VT-100 type terminal using the rear-
mounted EIA-232 Control Port. Netlink-T1™ supports D4/ESF framing
options and AMI/B8ZS/B7ZS line coding. Netlink-T1™ also supports a full
range of system and diagnostic features that make system setup easy.
The NetLink-T1™ provides T1 terminations over a modular RJ-48C jack
and comply with jitter tolerance capabilities as specified in ANSI T1.403 and
AT&T TR62411. External power options include 120VAC and universal
interface 100-240VAC. 48VDC and rack card versions are also available.
Figure 1. Underside of Model 2720, Showing Location of DIP Switches
Front
Rear
OFF
S1
S2
ON
1234
ON
5678
Figure 2. Close up of DIP switches showing ON/OFF positions.

8
3.1.1 Switch S2
The table below shows the default configurations for Switch S2. A
description of all S2 options follows this table.
Switches S2-1, S2-2, and S2-3
Use Switches S2-1, S2-2 and S2-3 to set the DTE data rate.
Each setting represents an nx56/nx64 setting. Individual channel set-
tings can be configured through the software control port.
S2-1 S2-2 S2-3 Speed
Off Off Off Clear Channel (Unframed)
On Off Off 112kbps/128kbps
Off On Off 224kbps/256kbps
On On Off 336kbps/384kbps
Off Off On 448kbps/512kbps
On Off On 672kbps/768kbps
Off On On 896kbps/1024kbps
On On On 1344kbps/1536kbps
Switch S2-4: Line Framing and Coding
Use Switch S2-4 to control the Network Line Framing and Coding
Options. Set these options to be the same as the Line Framing and
Coding Options given to you by your Service Provider. If you are using
two Model 2720s together as short range modems, set both units iden-
tically.
S2-4 Line Framing & Coding
Off ESF/B8ZS
On D4/AMI
Line Framing Options:
D4/Superframe: The D4 framing format, as specified in AT&T
TR62411 is the standard in which twelve frames make up a
superframe. All signaling and synchronization are done in-
band.
Extended Superframe (ESF): Extended Superframe, as speci-
fied in AT&T TR 54016, consists of twenty-four (24) T1
frames. The framing bits are now used for framing, CRC and
the Facility Data Link (FDL). The FDL allows maintenance
messages and information to be passed between the 2720
and the Central Office.
Line Coding Options:
Alternate Mark Inversion (AMI): This mode does not inherently
account for ones density. To meet this requirement, each time
slot can be reduced to 56 kbps and the Least Significant Bit
(LSB) of each time slot set to one.
Bipolar 8 Zero Substitution (B8ZS): This mode assures proper
bit density in the data stream. In this mode any data pattern
can be transmitted without causing ones density errors. This
mode allows for 64 kbps clear channel timeslots.
Switch S2-5: DS0 Channel Rate
Use Switch S2-5 to set the DS0 rate.
SW2-5 Setting
Off 56 kbps
On 64 kbps
S2 SUMMARY TABLE
Position Function Factory Default Selected Option
S2-1 Data Rate On
S2-2 Data Rate On
S2-3 Data Rate On
S2-4 Framing & Coding Off
S2-5 DS Zero Rate On
S2-6 Clock Mode Off
S2-7 Clock Mode Off
S2-8 Reserved Off
1.536 Mbps
(DTE Rate)
ESF/B8ZS
64 kbps
Network
Reserved
Network
7

3.1.2 Switch S1
The chart below shows the default configurations for Switch S1. A
description of all S1 options follows this table.
Switch S1-1: RDL Type
Switch S1-1 selects the type of Remote Digital Loopback that the
2720 will initiate when the RDL is initiated from this unit. The 2720 will
respond to both the V54 and the CSU loopback regardless of the set-
ting of S1-1
S1-1 RDL Type
On Initiate a V.54 RDL loop when selected
Off Initiate a CSU loopback when selected
Switch S1-2: Tx Clock Select
Switch S1-2 selects the clock that is used to accept the Transmit
Data from the DTE interface. Standard DTE interfaces will transmit
data with respect to the External Clock. In some cases a DTE interface
will transmit with respect to the Transmit clock sent out from the 2720.
Please review the information provided with your DTE equipment for
more information on its' operation. In most cases when there are errors
on the line only in the direction of the transmit data either S1-2 or S1-3
can be changed to solve the problem.
S1-2 Tx Clock Select
On Transmit data accept with respect to the transmit
clock from the 2720
Off Transmit data accept with respect to the external
clock from the DTE
Switch S2-6 and S2-7: Clock Mode
Set Switch S2-6 and S2-7 to determine the 2720’s transmitter tim-
ing.
S2-6 S2-7 Clock Mode
Off Off Network Clock . Transmitter timing is
derived from the received line signal.
On Off Internal Clock . Transmitter clock is
derived from an internal oscillator.
Off On External Clock. Transmitter clock is
derived from DTE interface.
NOTE 1: When using the Model 2720 as a high-speed short
range modem, one unit of the link must be configured in
Internal/External Clock mode, and the opposite end unit must be
configured for Network Clock mode.
If the ERR LED on the front of the unit is flashing (or on) it could
be an indication of a clocking problem. Double check your clock
mode settings and your Tx Clock Select (S1-2) and Tx Clock
Invert S1-3 settings.
Switch S2-8 Reserved
910
S1 SUMMARY TABE
Position Function Factory Default Selected Option
S1-1 RDL Type On
S1-2
Tx Clock Select Off
S1-3
Tx Clock Invert Off
S1-4
Line Build Out Off
S1-5 Off
S1-6
Reserved Off
S1-7
Reserved Off
S1-8 Reserved Off
V.54 RDL
External Clock
Normal
0dB

11 12
Switch S1-3: Tx Clock Invert
Switch S1-3 allows the user to invert the transmit clock originating
in the 2720. When S1-2 is set for transmit clock, it may be necessary
to invert the transmit clock to allow for delays due to long cables.
S1-3 Tx Clock Invert
On Transmit clock is inverted
Off Transmit clock is normal
Switches S1-4 and S1-5: Line Build Out
Use Switches S1-4 and S1-5 to set the Line Build Out (LBO). The
Line Build Out varies the pulse shape and attenuation of the signal
sent to the network. The amount of Line Build Out depends on
NetLink™ T1’s distance to the last repeater. The telephone company
providing the service will advise on the amount of LBO necessary. In
most cases the default setting will suffice.
SW1-4 SW1-5 Function
Off Off -0dB
On Off -7.5dB
Off On -15.0dB
On On -22.5dB
Switch S1-6 Through S1-8: Reserved
3.2 SOFTWARE CONFIGURATION
The Model 2720 features a menu-driven command system that
allows you to monitor/configure its operating parameters. Follow the
instructions below to configure the Model 2720 using the software
selections:
1) Plug the 9-pin male end of the cable to your terminal or com-
puter’s DB-9 serial port and start up the terminal emulator
software if necessary. Plug the miniature stereo plug into the
rear of the unit. The small recessed jack on the left side of
the unit is the control port jack.
NOTE: If your terminal uses a DB-25 connector, please use a
DB-9 to DB-25 Adapter to connect to the cable.
2) Power up the terminal and set its RS-232 port as follows:
9600 Baud
8 data bits, 1 stop bit, no parity
Local echo off
ANSI or VT-100 emulation
3) Here is an example of a terminal emulator setup session. In
normal font are the various parameter types. In bold type are
the values that should be used for best results. Your terminal
program’s setup screen may differ from this one:
Baud rate: 9600 Parity: None Data Length: 8Stop Bits: 1
Default terminal type: VT100
Local Echo: Off
Add Line Feeds after CRs: Off
Received Backspace Destructive: On
Backspace key sends: BS
XON/XOFF software flow control: On
CTS/RTS hardware flow control: Off
DSR/DTR hardware flow control: Off

13 14
4) When the unit is first turned on, the terminal screen may
appear blank. Press the [Enter] key. If your serial connection
is good, the unit will immediately display a password prompt.
The following message will appear in the middle of the
screen:
5) Type in the password and press [Enter]. The factory default
password for the unit is (password is case sensitive):
patton
NOTE: If the entry is incorrect, the password screen will clear
and prompt you again for the correct password. The password
you enter will not be shown. For security, asterisks will be dis-
played for each letter you type. The maximum length of the
password, which can include any character the terminal can
generate, is 16 characters.
6) The Model 2720 will then display the Main Menu screen.
Patton Electronics
Menu Management
Enter Password: _
3.2.1 Introduction to Main Menu
After entering the password, you may access all of the system’s
functions and parameters. The Main Menu looks like this:
HELPFUL HINTS
1. To make a selection, key the highlighted letter that corre-
sponds to a menu selection.
2. To execute the selection, type [Enter/CR]
3. To toggle between options on a highlighted selection, Press
[space].
4. Select Save Changes from Main Menu after making modi-
fications to any Model 2720 parameter. Otherwise, changes
will be lost when the Model 2720 is turned off.
Header Line 1 Header Line 2
Highlighted items
Commands
Commands and text entered here
_
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15 16
The Main Menu options are briefly described below.
System Configuration options allow you to change various
aspects of the Model 2720’s operation, e.g., framing, line cod-
ing, and aggregate bandwidth.
System Diagnostics/Statistics options allow you to monitor
the network performance, initiate V.54 loops, local loops, and
send test patterns. Network performance parameters are
updated once a second, giving you the ability to quickly deter-
mine if there is a problem.
Unit Information allow you to customize the Model 2720 for
your location. You can change the default header names to
give each unit a unique name and password. Also, you can
reset the unit to its default settings without the manual. It also
has a Service Information screen in case you need technical
assistance from Patton Electronics.
Implement and Save Changes. Once you have configured
the unit to your satisfaction, you can save the changes per-
manently by executing the Save Changes command. This will
update the unit’s configuration and save all the parameters to
permanent memory.
Logoff. For security, log off the control menu by executing
the Logoff command. This will blank the screen until an
[Enter] key is pressed.
a
b
c
d
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3.2.2 System Configuration
The default System Configuration menu looks like this:
The System Configuration options are described below:
Line Format: ESF (default)
Options: ESF, D4, UNFRAMED
D4: This is an older, but widely used, line format that does not
provide FDL, so network interface performance cannot be
monitored so easily. AT&T TR 62411 contains the specifica-
tions for this format and the ESF. D4 is also known as
Superframe format. According to TR 62411, “The Superframe
format…consists of 12 frames of 193 bits each for a total of
2316 bits. Each 193 bit frame consists of 192 bits preceded
by one framing bit….the framing bit is time shared to both
synchronize the terminal equipment and to identify the signal-
ing frames.” (Sec. 4.1.1)
a
Commands and text entered here
_

17 18
ESF: This stands for Extended Superframe Format, a line format
developed by AT&T. AT&T Technical Reference 54016 (TR
54016) defines the ESF, a format which is commonly used to
allow monitoring of the network interface performance over
the Facility Data Link (FDL). AT&T TR 62411 says, “the
Extended Superframe Format “extends” the DS1 superframe
structure from 12 to 24 frames…for a total of 4632 bits. It
redefines the 8 kb/s channel previously used exclusively for
terminal and robbed bit signaling synchronization.” The ESF
provides a 4 kb/s data link, called the FDL, which allows for
in-service monitoring and fast troubleshooting. Certain net-
work services require the ESF.
UNFRAMED:This is a special mode that allows you to achieve the
maximum possible data rate of 1.544 Mb/s (million bits per
second) by using the framing bits for data transmission. There
is no signaling or FDL. This is commonly used for campus
connections, and by the Federal government and the military.
This format is not to be used when connecting to a public car-
rier’s network without its permission. This provides one chan-
nel at a rate of 1.544 Mb/s. In addition, this format can be
used with external clocking.
Line Coding: B8ZS (default)
Options: AMI, B8ZS, B7ZS.
AMI: Alternate Mark Inversion defines a pulse as a “mark”, a
binary one, as opposed to a zero. In a T1 (DS1) 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
CSU/DSU receiving the signal relies on the signal to recover
the 1.544 Mb/s clock. To get around this problem, one method
is to limit the data rate per channel (known as a DS0,
because it is a 64 kb/s portion of the DS1 frame or super-
frame) to 56 kb/s and forcing a pulse in the last data bit to
ensure a minimum pulse density in the signal. If you must use
AMI with a DS0 data rate of 64 kb/s, you should ensure that
the data terminal equipment connected to the unit provides a
minimally acceptable pulse density. For this reason, there are
advantages to using B8ZS instead.
b
B8ZS: Bipolar violations occur when consecutive pulses are of
the same polarity. In B8ZS, or Bipolar Eight Zero Substitution,
bipolar violations are introduced deliberately to indicate that
eight zeros have been transmitted. This special encoding is
recognized by the receiver and decoded correctly. See AT&T
TR62411 Section 4.2.2 for a detailed description of B8ZS.
This enables information to be sent over a T1 connection
without any constraints on the data’s pulse density. This is the
most acceptable way to accomplish 64 kb/s on each DS0
channel.
B7ZS: This stands for Bipolar Seven Zero Substitution. Instead of
introducing bipolar violations, this method substitutes a one
for a zero in bit 7 (out of 8) of a DS0 channel when the data in
that channel are all zeros. This is a special form of AMI and is
compatible only with special equipment. For most applica-
tions, AMI or B8ZS will suffice.
DS0 Line Rate: 64kbps (default)
Options: 64kbps, 56kbps
64kbps: Also known as Clear Channel, this takes full advantage
of the available bandwidth in a DS0 channel. Implementing it
usually requires B8ZS line coding. In certain cases, special
equipment may implement Clear Channel using AMI or B7ZS.
Consult the equipment manual for compatibility. Your carrier
will advise you on whether to use 64 or 56 kb/s. Campus
applications may not have such restrictions, enabling you to
use 64kbps. In Unframed format, the 24 DS0s and the fram-
ing bits are combined to provide 1.544Mb/s for your use.
56kbps: This uses only the first seven bits of the DS0, limiting the
data rate per DS0 channel to 56 kb/s. Your carrier will advise
you on whether to use 64 or 56 kb/s. This is not available
when using the Unframed format.
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19 20
Clocking: Network (default)
Options: Network, Internal, External
Network: This is the most commonly used setting when connect
ing to a carrier’s network. In this mode, the unit recovers the
clock from the received signal and uses it to transmit data. In
this way the unit remains synchronized to a master clock. In
campus applications, one of the units must be set to Internal
clock, and the other end is set to Network clock. At all times,
there must be only one clock source. Otherwise, clock slips
and framing errors and bit errors may occur.
Internal: This is commonly used in campus applications, where
the unit is not connected to the public telephone network
directly. In this mode, the unit uses the on-board oscillator as
the transmit clock source.
External: This is a special mode that should only be used with
the Unframed format. In this mode, the unit requires a 1.544
Mhz clock signal from the DTE via the external clock pin on
the DTE interface connector. Most applications will use
Network or Internal clock modes.
Line Build Out (dB): 0 – 133 feet, 0 dB (default)
Options: 0 – 133 feet, 0 dB
133 – 266 feet
266 – 399 feet
399 – 533 feet
533 - 655 feet
-7.5 dB
-15.0 dB
-22.5 dB
This controls the transmitter signal strength and pulse shape. For
most applications, the default setting will suffice. When connecting to a
carrier connection, the carrier will determine what LBO is necessary. 0
dB provides the highest signal strength and therefore the longest dis-
tance, while –15.0 dB provides the lowest usable signal strength. The
last setting, –22.5 dB, is usually only used to test the line and should
not be used in normal applications.
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ESF Data Link: ANSI T1.403 (default)
Options: ANSI T1.403, AT&T TR54016
ANSI T1.403: This ANSI developed standard (see ANSI T1.403-
1995: Network-to-Customer Installation—DS1 Metallic
Interface) uses the FDL to send and receive one second
Performance Report Messages (PRMs). The messages con-
tain the NI performance over the last four seconds. Thus, up
to three consecutive messages may be lost without loss of
information. It is available only with ESF. When ANSI T1.403
is selected, requests to send AT&T performance reports (ref.
AT&T TR 54016) are ignored.
AT&T TR54016: Developed by AT&T, this FDL method differs
principally from the ANSI method in two ways: First, the ANSI
method transmits messages continuously, whereas the AT&T
method transmits a performance report only upon a request
from the remote end for a report. Second, the AT&T method
provides a historical summary, up to the last 24 hours, of NI
performance. Only the service provider or special test equip-
ment can send these requests. When AT&T TR54016 is
selected, ANSI PRMs are still transmitted by the unit, but only
PRMs sent by the carrier will be recognized. To receive PRMs
from another customer unit (i.e., in a campus application),
select ANSI T1.403. When the frame is not ESF, the FDL is
disabled.
ESF Carrier Loops: Enabled (default)
Options: Enabled, Disabled
The ESF format provides the CO the ability to put the customer
installation’s Model 2720 into loopback mode. The Model 2720 recog-
nizes these special messages that are sent over the FDL. When
enabled, the unit will respond to these loopback commands and go into
or out of loopback mode. When disabled, the unit will not respond,
although it still recognizes the loopback commands. When in loopback,
the unit will remain in loopback until a loopback exit command is
received or when the loopback timer times out. See Unit Options
(Section 3.2.4) to make Loop Timeout choices. This feature allows the
remote user to regain control should one be locked out after a loop-
back is initiated.
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Remote In-band Loops: Enabled (default)
Options: Enabled, Disabled
In ESF, D4 and Unframed formats, the unit can respond to special
repeating codes in the data stream that represent loopback com-
mands. The command to loop up (go into loopback) is a repeating pat-
tern of 00001s. This pattern overwrites the normal data. When this
code is detected for 5 seconds, the unit will go into loopback if the
Remote In-band Loopback is Enabled. When a repeating code of 001s
is received for 5 seconds, the unit loops down (goes out of loopback).
The delayed recognition guards against false starts, since the code
must be present for a long time continuously. When Disabled, the unit
will recognize the codes but will not respond to them. The loopback
timeout also applies to this feature.
V.54 Loops (RDL Only): Enabled (default)
Options: Enabled, Disabled
This is a special in-band loopback facility that sends a special
pseudo-random pattern over the data stream. This is the only remote
loopback that the unit can initiate. This is useful for campus applica-
tions when you need to put a remote unit in loopback. The remote unit
responds to the V.54 loopback command, and the whole process takes
only a few seconds to complete. This setting will enable/disable RDL
from being initiated from either the control port or the DTE interface. It
will also enable/disable the unit to respond to the V.54 command if
received over the line. The duration of the loopback is limited by the
loopback timeout setting. (See Unit Operations, paragraph 3.2.4, on
pages 32 and 33.)
Default Config Source: Switch (default)
Option: EEPROM, Switch
The Model 2720 can be initialized via the configuration in the on-
board permanent memory (EEPROM) or via the internal DIP switches
(Switch). Once the unit is powered up, you may change the settings
through the control port or the DIP switches.
If you do not have a terminal, you may force the unit to use the
DIP switches as the default configuration source by turning off the unit,
setting all the DIP switches to the ON position, then powering on the
unit. This will cause the unit to enter a special mode. Then turn off the
unit and change the switch settings to the desired settings. When you
turn the unit on again, the unit will be set up with the selected switch
settings.
DS0 Channel Configuration Menu: [ Bandwidth/# Channels =
1,536/24 ] (default)
The DS0 Channel Configuration Menu has a sub-menu that looks
like this:
You may configure the Model 2720 to operate with any combina-
tion of active and inactive DS0 channels in this screen. When you exe-
cute the Save Changes command, the selected settings will be saved
to permanent memory, and the system will be updated to operate with
the new channel settings.
NOTE: In Unframed format, the Bandwidth Selected will display
“1,544k,” and the Total Channels will display “n/a.” When the DS0
Channel Rate is 56kbps, the Bandwidth Selected will be a multiple
of 56k, not of 64k. When using the DIP switches to set the band-
width, the starting channel is always channel 1.
Front Panel Switches: Enabled
Options: Enabled, Disabled
Front panel switches(2) activate Local/Remote Loops and
Test patterns. Both switches can be enabled or disabled Via
this software option.
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3.2.3 System Diagnostics
The System Diagnostics/Statistics screen looks like this:
NOTE: This screen is updated once per second.
The System Diagnostics/Statistics options and functions are
described below.
Local Loop: Idle (default)
The Local Loop is a bi-lateral loopback in which the data from the
local DTE and the data from the remote unit are looped back to their
respective sources (See Section 5.3). Activate this loop to test the
each of the DTE’s connection to the Model 2720.
The Local Loop test has four states:
Idle No user-controlled loopbacks are active.
LL The Model 2720 is in local loopback mode.
Off The Model 2720 is in remote or CO initiated loopback
mode or sending a pattern. Local loopback is disabled.
LocP The Model 2720 is in Local Loopback mode, and is send-
ing a test pattern
.
Remote Loop Idle (default)
The Remote Digital Loopback (RDL) test checks the performance
of both the local and remote Model 2720s, as well as the communica-
tion link between them. Data from the local DTE is sent across the
entire communication circuit and looped back to the local DTE.
The Model 2720 Initiating a RL can be in one of the following
states:
Idle No user-controlled loopbacks are active.
TxPr The Model 2720 is sending the preparatory phase pattern
lasting for approximately 2 -5 seconds.
WtAk The Model 2720 is waiting for an acknowledgement from
the remote unit. If the remote unit does not respond, the
WtAk message will remain on the screen.
RxAk The Model 2720 has received an acknowledgement from
the remote unit.
Tout The Model 2720 is waiting before entering the Remote
Loopback test mode.
TM The Model 2720 has successfully negotiated the Remote
Loopback test and is in control of the remote unit. You
may send a test pattern at this point by pressing:
c <spacebar>
TxTr The Model 2720 is sending a Terminate Loopback mes-
sage to the remote unit. If the remote unit does not
respond, the local unit will return to the Idle state.
Tx1s If the remote Model 2720 responds to the local NetLink-
T1™’s terminate loopback request, the local unit then
sends an all ones pattern before returning to the Idle
state
TxP The Model 2720 is sending a test pattern while in Test
Mode
IdlP The Model 2720 is sending a test pattern in place of data.
The Model 2720 is not in test mode.
a
DIP Sw. setting
Link status display
indicates the cable may
not be connected
Error
Counts
15 min increments
and # of seconds
in current interval
Commands and Text entered here Received ANSI performance
report message(PRM)(ESF)
only
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25 26
The Model 2720 receiving a RL can be in one of the following states:
RxPr The Model 2720 is receiving a preparatory pattern.
Sack The Model 2720, upon receiving a preparatory pattern,
sends an acknowledgement message.
RL The Model 2720 is in remote loopback mode.
RxTr The Model 2720 is receiving a terminate loopback mes-
sage.
Wt1s The Model 2720 is waiting for a sequence of all ones and
will time out if it does not receive it.
IdleP The Model 2720 is sending a QRSS, 511 or 2047 pattern.
Off The Model 2720 is in local loopback.
Test Pattern Idle (default)
Options: Idle or Sending
To send a pattern, press the ‘c’ key and press <spacebar> to send
the test pattern. The “OK” message indicates the received test pattern
is error-free. The “BE” message indicates errors in the received pat-
tern.
Idle Indicates that Model 2720 is not sending a pattern.
Sending Indicates that 2720 is sending a pattern.
Error Insertion Off (default)
Options: On, Off
You may inject intentional errors into the test pattern by turning
Error Insertion ON. The Error (ERR) LED will blink once per second.
Selected Pattern QRRSS (default)
Options: QRSS, 511, or 2047
Use this option to select the test pattern used to test the link.
Note: The front panel test pattern switch will initiate the test pattern
selected in this menu (default QRSS).
Network Interface (NI) STATUS
The Network interface (NI) status is shown in
the middle of the Diagnostics/Statistics screen. The brackets are
empty when the link is operating normally. In this example, various two
or three-letter messages are displayed within the brackets, illustrating
what you may see if the Model 2720 is not connected at all or is in a
loss of signal condition. Here are the eight status messages.
Excessive zeros [EXZ], i.e., lack of pulses, detected. This condition
may occur if the unit is not connected to the network, in which case the
EXZ is displayed continuously. If EXZ comes on intermittently, there
may be a frame, line code or data rate mismatch between the near and
far-end units.
Receiver Carrier Loss [RCL] occurs when 192 consecutive zeros
have been detected at the network interface. RCL clears when a pulse
is detected.
Frame Bit Error [FE] occurs when there is an error in the framing bit
sequence. This may happen due to a disconnected line, mismatched
framing formats or severe errors in the data stream. This error may
indicate a noisy line or cable condition. This error may indicate a noisy
line or cable connection if the frames appear to be set correctly.
Severe Frame Error [SE] occurs when the framing error exceeds a
certain threshold of errors. This may happen due to a disconnected
line, an extremely noisy connection, or mismatched framing.
Loss of Sync [LOS] occurs when the T1 framer in the unit cannot
synchronize itself to the received data stream. This may happen due to
a disconnected line.
Out of Frame [OOF] occurs when no valid frame structure can be
found. This may happen due to a disconnected line or mismatched
framing or mismatched framing.
Alarm Indication Signal [AIS] indicates that the remote unit or the
central office is sending a Blue Alarm, because it is not receiving a sig-
nal; the alarm is an unframed all-ones signal, mainly used to keep the
line alive and to indicate that it is not receiving any signal. This may
indicate that the local unit is receiving a good signal, but that the trans-
mit link may be broken.
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27 28
Receive Alarm Indication [RAI] indicates that the local unit is receiv-
ing a Yellow Alarm. This alarm is sent by the remote unit or the central
office when it loses the received signal. This indicates the local unit’s
transmitted signal is not reaching the remote unit.
Rx Level The Model 2720 displays the current received signal
strength in dB. There are four level ranges detected:
+2 to –7.5
-7.5 to –15
-15 to –22.5
< -22.5
Valid Interval Count & Current Interval Time
The Valid Interval Count and Current Interval Time display the
number of valid 15 minute intervals in the last 24 hours and the num-
ber of seconds which have elapsed in the current interval, respectively.
The Valid Interval Count saturates at the count of 96 (96 * 15min = 24
hours), while the Current Interval Time rolls over after 900 counts.
When the counter rolls over, it is reset to zero, and the Interval Counter
is incremented by one if the count is less than 96.
Error Counters
These error counters give a second-by-second snapshot of the
link performance. To clear all counters, press the [Backspace] key. If
your keyboard does not have this key, you can press a two-key combi-
nation to affect the same result: Hold down the [Ctrl] key and then
press the [H] key. This will send to the unit the Ctrl-H character, which
is the same as pressing the [Backspace] key.
Rx PRM
The NetLink-T1™ transmits ANSI performance report messages
once a second when the framing mode is ESF. When the ESF Data
Link is set to ANSI T1.403, the unit recognizes PRMs with addresses
of 38h or 3Ah. The address 3Ah indicates the PRM is coming from a
Carrier, whereas the address 38h indicates the PRM is coming from a
Customer. When the ESF Data Link is set to AT&T TR54016, the unit
recognizes Carrier-originated PRMs, which have an address of 3Ah.
Current DIP Switch Settings
The Switch settings are displayed here to
facilitate troubleshooting your unit without
opening up the unit first.
Valid Interval Count: [96]
Current Interval Time: [899]
ERR SEC: 0 0 Errored Seconds in Current Interval....
UAS SEC: 557 209 Unavailable Seconds
SE SEC: 0 0 Severely Errored Seconds
BE SEC: 0 0 Bursty Errored Seconds
LOF SEC: 0 0 Loss of Frame Error Seconds
Rx PRM: 00010000000300023289

29 30
3.3.6 Unit Information
The Unit Options screen looks like this (factory default):
Header Line 1 & Header Line 2
Headers 1 and 2 are provided for easy identification of your unit
after installation. You may want to give each unit a unique name via
the header lines to help distinguish one unit from another. You can
enter a header up to 40 letters long. Two lines provide 80 letters for
your use. That’s a lot of flexibility!
Password
The Password facility provides security by allowing only those who
know the correct password to configure the unit via the control port.
You can still configure the unit via the DIP switches. The password can
be up to 16 characters long, with no restriction on the combination of
characters you can use, so be sure to remember the password. If you
lose your password, you will lose the ability to access the unit via the
control port.
Loop Timeout
The Loop Timeout setting can be set to one of the following:
00:05 = five minutes
00:10 = ten minutes
00:15 = fifteen minutes
00:30 = thirty minutes (default setting)
00:45 = forty-five minutes
01:00 = one hour
01:30 = 90 minutes
02:00 = two hours
03:00 = three hours
NEVER = forever—the unit will remain in loopback without user
intervention.
Note: Loop timeout settings are efective only for VT-100 initiated
Loops. Loops initiated via DTE interface or front panel switch are
not affected, therefore they must be terminated accordingly.
Tx Data Clock
This option selects the clock that is used to accept the Transmit
Data from the DTE interface. Standard DTE interfaces will transmit
data with respect to the External Clock. In some cases a DTE interface
will transmit with respect to the Transmit clock sent out from the 2720.
Please review the information provided with your DTE equipment for
more information on its' operation. In most cases when there are errors
on the line only in the direction of the transmit data either Tx Data
Clock or Tx Clock Invert can be changed to solve the problem.
Tx Clock Invert
This option allows the user to invert the transmit clock originating
in the 2720. When Tx Data Clock is set for transmit clock, it may be
necessary to invert the transmit clock to allow for cable delays.
Set to Default Configuration
You may set the NetLink-T1™ to its factory default configuration,
except for the header lines and the password, by executing the Set to
Default Configuration command.
Service Information
Provide the user with contact information for Patton Electronics
Technical Support.
Clear Errors
Allows the user to clear the error indication counter.
a
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31 32
4.0 INSTALLATION
The Model 2720 is equipped with DTE, network, and power inter-
faces. This section briefly describes connection to each.
4.1 DTE INTERFACE CONNECTION
The DTE interface is a V.35 DCE presented as an M/34 male con-
nector. This interface is designed to plug directly into a DTE interface
(See Appendix D for V.35 interface pin assignments).
4.2 NETWORK INTERFACE CONNECTION
The Network Line Interface is an eight position keyed modular jack
configured as a RJ-48C. This interface will need to be configured to
match the line parameters (i.e. framing, line coding, etc.) supplied by
the central office.
4.3 DC POWER SUPPLY
The 36-60 VDC DC to DC adapter is supplied with the DC version of
the Model 2720. The black and red leads plug into a DC source (nomi-
nal 48VDC) and the barrel power connector plugs into the barrel power
supply jack on the 2720.
5.0 OPERATION
Once the NetLink-T1™ is installed and configured properly it is
ready to place into operation. This section describes the function of
the LED indicators, and the use of the loopback and pattern test
modes.
5.1 LED DESCRIPTIONS
The NetLink-T1™ is equipped with six LED indicators that monitor
the status of communication. Figure 12 (below) shows the location of
the LEDs on the NetLink-T1™ Series front panel.
T1 Link Solid green indicates that the end to end TI
link is up. Signifying that the link is active.
The TI link LED is off when the link is down
TD When the unit sends a one, the TD LED is
green. When it sends a zero, the TD LED is
orange. Moreover, the TD LED is active
only in active DS0 channels. In inactive
channels, the TD LED is off.
RD When the unit receives a one, the RD LED
is green. When it receives a zero, the RD
LED is orange. Moreover, the RD LED is
active only in active DS0 channels. In inac-
tive channels, the RD LED is off.
ALM The alarm LED indicates the presence of a
Blue or Yellow Alarm, or Out of Frame con-
dition. The ALM LED will blink on every half-
second. Alarms may occur due to:
• Loss of Synchronization
• Loss of Frame
• AIS (Blue Alarm)
• RAI (Yellow Alarm)
Figure 2. Model 2720 twisted pair line interface.
1 RX Data (TIP)
2 RX Data (RING)
3 (no connection)
4 TX Data (TIP)
5 TX Data (RING)
6 (no connection)
7 (no connection)
8 (no connection)
1
2
3
4
5
6
7
8
NOTE:
If the Model 2720 is being used for private short range
modem applications, the twisted pair cable connected to
its port will need to be a crossover cable. See Appendix
D for Interface pin assignments.
} From Network
} To network
To Power
Supply Jack To -48VDC
Source
-Vin
+Vin
SWITCHING POWER SUPPLY MODEL : SYD1106-0505 INPUT : 36-60V 0.2A MAX OUTPUT : +5V 1.0A OUTPUT POWER : 5W MAX
S/N: G01234567890 MADE IN CHINA BYSUNNY
Black lead (-V)
Red lead (+V)
Barrel power connector
Figure 3: 2720/C Front Panel

33 34
ER The error LED indicates various error condi-
tions, including framing bit errors, excessive
zeros, controlled slips, severe errors, or bit
errors (when sending V.52 test patterns).
When sending a test pattern, the LED will
remain lit if the unit does not receive the
identical pattern. When it receives the cor-
rect pattern, the LED will turn off. If error
insertion is on, the LED will blink once a
second if everything is operating properly.
TM The test indicator LED blinks with a specific
pattern depending on the type of test mode.
When the unit is in local analog loop, the
LED will blink on briefly. When the unit is in
remote loop, the TM LED will blink off
briefly. When the unit is sending a test pat-
tern or is putting the remote unit into
V.54/CSU loopback, the TM LED will stay
on. These are the test modes:
• V.54/CSU Loopback & V.52 Patterns
• D4 Line Loop (CO initiated)
• ESF Line Loop (CO Initiated)
• ESF Payload Loop (CO Initiated)
5.2 LOOP (V.54 & TELCO) DIAGNOSTICS
The NetLink-T1™ offers three V.54 loop diagnostics and is com-
patible with two Telco loop diagnostics. Use these diagnostics to test
the CSU/DSU and any communication links. These tests can be acti-
vated via the software control port (See Section 3.2.3 System
Diagnostics), via signals on the serial port interface or the front panel
switch.
5.2.1 Operating Local Loopback (LL)
The Local Loopback (LL) test checks the operation of the local
NetLink-T1™, and is performed separately on each unit. Any data sent
to the local NetLink-T1™ in this test mode will be echoed (returned)
back to the user device (i.e., characters typed on the keyboard of a ter-
minal will appear on the terminal screen).
To perform a LL test, follow these steps:
1. Activate LL. This may be done in one of three ways:
a. Enter Local Loop from the System
Diagnostics/Statistics menu and toggle the <Spacebar>
until “LL” appears next to the Local Loop option.
b. Activate the “LL” signal on the DTE. If you are not sure
which lead is the “LL” signal, please refer to Appendix D.
c. Toggle the front panel switch to the “Local” position.
2. Verify that the data terminal equipment is operating properly
and can be used for a test.
3. Perform a V.52 BER (bit error rate) test as described in
a
a
Figure 7. Local Loopback
Serial
Device
Serial
Device
Receive
Recover
Clocking
Internal
Clocking
Cable Span
T1/FT1 CSU/DSU
Model 2720/X T1/FT1 CSU/DSU
Model 2720/X
Clock/
Data
Clock/
Data
Clock/
Data
Data
Data
Model 2720/X Model 2720/X RC
LLB Initiated

35 36
Section 5.3. If the BER test equipment indicates no faults,
but the data terminal indicates a fault, follow the manufactur-
er’s checkout procedures for the data terminal. Also, check
the interface cable between the terminal and the NetLink-T1.
5.2.2 Operating Remote Digital Loopback (RL)
The Remote Digital Loopback (RL) test checks the performance of
both the local and remote NetLink-T1™, as well as the communication
link between them. Any characters sent to the remote NetLink-T1™ in
this test mode will be returned back to the originating device (i.e, char-
acters typed on the keyboard of the local terminal will appear on the
local terminal screen after having been passed to the remote NetLink-
T1™ and looped back).
There are two Remote Loops that can be initiated from the
NetLink-T1 unit: (1) V.54 Loop, and; (2)CSU Loop. The user can
select the type of loop that can be initiated from the System
Diagnostics/Statistics screen or with Switch S1-1. Select “c” RDL
Type and press the <spacebar> to toggle between the CSU loop and
the V.54 loop. When a loopback is initiated this is the type of loop that
the unit uses to loop up the remote unit. NOTE: The NetLink-T1 will
respond to both loops regardless of the state of the RDL Type.
To perform an RDL test, follow these steps:
1. Activate RDL. This may be done in three ways:
a. Enter Remote Loop from the System
Diagnostics/Statistics menu and toggle the <Spacebar>
until “RL” appears next to the Remote Loop option.;
b. Activate the “RL” signal on the DTE. If you are not sure
which lead is the “RL” signal, please refer to Appendix D.
c. Set the front panel switch to ‘Remote’.
2. Perform a bit error rate test (BERT) using the internal V.52
generator (as described in Section 5.3), or using a separate
BER Tester. If the BER test indicates a fault, and the Local
Line Loopback test was successful for both NetLink™s, you
may have a problem with the twisted pair line connection.
5.2.3 CSU Loop
The NetLink-T1™ also responds to central office initiated loop com-
mands. The NetLink-T1™ will implement the “loop up” command when
it recognizes the pattern “10000” in the data stream for a minimum of 5
seconds. The “loop down” command is implemented by the pattern
“100” in the data stream for a minimum of 5 seconds.
When operating in ESF framing mode, loopback commands are
issued via the Facility Data Link (FDL). The line loop message will
cause a loop back before data enters the framer portion of the CSU.
The payload loop message will cause the NetLink-T1™ to loop data
after the framer portion of the CSU.
The NetLink-T1™ will respond to Universal Loopback De-activate
to clear all central office loops.
5.3 BIT ERROR RATE (V.52) DIAGNOSTICS
The NetLink-T1™ offers three V.52 Bit Error Rate (BER) test pat-
terns. These test patterns may be invoked along with the LAL and
RDL tests to evaluate the unit(s) and the communication links.
When a 511, 2047, or QRSS test is invoked, the NetLink-T1™
generates a pseudo-random bit pattern of 511 bits, 2047 bits or 220 bits,
respectively, using a mathematical polynomial. The receiving NetLink-
T1™ then decodes the received bits using the same polynomial. If the
received bits match the agreed upon pseudo-random pattern, then the
NetLink-T1™(s) and the communication link(s) are functioning properly.
511 Initiates a built-in 511 bit pseudo-random
pattern generator and detector.
2047 Initiates a built-in 2047 bit pseudo-random
pattern generator and detector.
QRSS Initiates a built-in 220 bit pseudo-random
pattern generator and detector.
b
b
Figure 8. Remote Loopback
Serial
Device Ethernet
Device
Model 2720/X
Receive
Recover
Clocking
Internal
Clocking
Cable Span
T1/FT1 CSU/DSU
Model 2720/X T1/FT1 CSU/DSU
Model 2720/X
Clock/
Data
Clock/
Data
Clock/
Data
Data
Data
Model 2720/X
RDL Initiated

To perform a V.52 test, follow these steps:
1. Activate the local loopback or remote loopback diagnostic.
2. Activate the test pattern. This may be done in one of two
ways:
a. Enter Selected Pattern from the System
Diagnostics/Statistics menu and toggle the <Spacebar>
until the desired test pattern appears.
One of two result codes will appear to the right of the
Test Pattern listing:
OK Indicates that the received test pattern is error-free.
BE Indicates that there are errors in the test pattern (to
deliberately insert errors in the pattern, toggle
Error Insertion to ON).
b. Toggle the front panel switch to either PAT or PAT/E (Test
Pattern with Error Injection).
c
38
APPENDIX A
PATTON NETLINK-T1 MODEL 2720
SPECIFICATIONS
WAN Speed: 1.544 Mbps
WAN Connection: RJ-48C
Nominal Impedance: 100 Ohms
DTE Interface: EIA-530 (DB25 female); V.35 (M/34
female)
Line Coding: AMI/B8ZS
Line Framing D4/ESF/Unframed
Receive LBO: Automatic
Transmit LBO: Selectable - 0, 7.5,
15, or 22.5 dB, plus DSX-1
Clock Options: Internal, external or network clock
Diagnostics: Responds to CO-initiated D4 loopup
and loopdown codes, ESF line loop
and payload loop FDL messages,
Universal Loopback De-activate mes-
sage
Standards: AT&T TR62411, TR54016, ANSI
T1.403
Power Supply: 120VAC, 60 Hz to 5VDC 300mA wall-
mount transformer; UI 100-240VAC,
50-60 Hz to 5 VDC, 2A desktop trans-
former; -48VDC to 5VDC, 500MA
Dimensions: 5.0’’ L x 42’’ W x 1.5’’ H
37
b