KX-TD500 Technical
Review
1
Table of Contents
Introduction
KX-TD500 Basic and Expansion Shelf
TD500 Cards
CPU Card KX-TD50101
TSW Card KX-TD50102
New KX-TD500 Cards
Other Cards Supported
System Construction
System Configuration
System Startup
Hardware Addressing
Maintenance Console Software
1-7
8-16
17
18-21
22-26
27-33
34-53
54-58
59-62
63-65
6680-90
2
Table of Contents
Activity
Activity
Activity
Activity
Activity
T1
Activity
Activity
Three
Four
Five
Six
Seven
Eight
Nine
91
92-98
99
100
101-102
103-122
123-128
129
3
KX-TD500
4
KX-TD500
Digital Super Hybrid
This TD-based system will offer a smooth
upgrade path for 2-cabinet TD1232 users
as well as a starter system for the
medium-sized businesses or high-end
residential users
5
KX-TD500
Digital Super Hybrid
The system will provide the TD dealers
with a larger system size, but offer a
similar programming and user interface as
currently offered by the TD308/816/1232.
The major differences between the
existing TD line of systems and the KXTD500 includes a new Windows-based
programming tool, and the universal slot
design.
6
KX-TD500 System Outline
The KX-TD500 consists of a basic shelf
and up to two expansion shelves.
The systems features a universal slot
design enabling station, CO, and other
function cards to be installed into free
slots in the cabinets.
7
Basic Shelf
KX-TD500
The Basic Shelf is the initial building-block
of the KX-TD500 system allowing a singlecabinet system to be configured with up
to a maximum of 192 ports.
The Basic Shelf then provides the
foundation on which the system can be
expanded by use of expansion shelves to
configure a system up a maximum of 512
ports.
8
Basic Shelf
KX-TD500
The Basic Shelf houses the system’s
common control cards including the
Central Processing Unit (CPU) card and
the Time Switch (TSW) card.
Only the TSW card is included with the
Basic Shelf which includes the DOHCA and
TSW-CONF cards
The CPU card is available separately.
9
Basic Shelf
KX-TD500
12 Free Slots (FS1-FS12) are available in
the Basic Shelf and can be carded with
CO, station, or other function cards as
required by the installations application.
If the installation location requires more
than the 12 slot configuration supports,
the system can be expanded by attaching
2 additional Expansion Shelves to the
upper portion of the Basic Shelf
10
Basic Shelf Includes:
Top panel with 3 LED indicators (Run,
Offline, Alarm)
2 Female RS-232C connectors
One for Programming
One for SMDR
An AC Power connector
11
Basic Shelf Includes:
Primary AC Power Supply with:
Main Power Switch
Grounding Terminal
AC outputs for Expansion Shelves
Shelf Power Supply with:
Power Switch
Power LED Indicator
Fuse
KX-A46 interface connector
12
Basic Shelf Includes:
Shelf Cooling Fan
SLT Ring Generator
Mounting Brackets
Side Panels
Lower Panel
Front Door with Lock
13
Expansion Shelf
KX-TD520
The KX-TD520 Expansion Shelf can be
installed onto the Basic Shelf adding on a
maximum of 216 additional ports. This
provides a two-cabinet system with a
maximum configuration of 408 ports.
A second Expansion Shelf could then be
added bring the system up to its
maximum port configuration of 512 ports.
14
Expansion Shelves Include:
14 Free Slots (FS1-FS14)
A Shelf Power Supply with:
Power Switch
Power LED Indicator
Fuse
KX-A46 Interface Connector
Shelf Cooling Fan
SLT Ring Generator
15
Expansion Shelves Include:
Side Panels
Front Door with Lock
Data and Power Connecting Cables
Mounting Hardware
16
TD500 Cards
Basic Cards
Basic Slot 1 = CPU Card, purchased from
parts
Basic Slot 2 = TSW Card, Factory Installed
Extension Cards
Trunk Cards
Resource Cards
Other Cards
17
KX-TD50101 CPU Card
386-based Main Central Processing Unit
Card residing in the Basic Shelf
This card provides control and call
processing data for all system functions
including TSW control, power down and
system clock alarms
Main components include 80386 CPU,
RAM, ROM, memory backup lithium
battery
18
KX-TD50101 CPU Card
CPU card also includes circuitry for the
RS-232C connectors
“System” and “Mode” switches are 10
position rotary switches located on the
front edge of the CPU card along with the
push reset switch.
The “System” switch is not used in the US
version.
19
KX-TD50101 CPU Card
The “Mode” switch is used to determine the
startup condition of the system. Although it
is a 10 position switch, only 4 position are
utilized for normal operations.
20
KX-TD50101 CPU Card
Mode switch positions are:
 Position
 Position
 Position
 Position
 Position
 Position
 Position
1
0,2,3,9
4
5
6
7
8
On-line while holding current data
On-line Same function as 1
Off-line holding current data
Off-line while defaulting system
ON-LINE with “backdoor” password
Off-line factory finished product testing
Off-line factory finished product testing
21
KX-TD50102 TSW Card
The Time Switch (TSW) card provides the
systems voice switching matrix including 72 3party conferencing circuits
The TSW card generates all audible call
progress tones, including dial tone, busy tone,
reorder and ringback tones
22
KX-TD50102 TSW Card
The TSW card also provides an interface for 2
Music on Hold inputs (9/64” mini-plug) and 2
External Paging output jacks (RCA plugs) with
volume adjustments
Two daughter boards are attached to the TSW
card
KX-TD50104
KX-TD50105
23
TSW Cards
The KX-TD50104 TSW-CONF Expansion Card
adds an additional 64 3-party conference
circuit to the basic 8 provided by the TSW
card
The KX-TD50105 DOHCA card allows for
OHCA for Digital Proprietary station cards
Both of these cards play an important role in
Digital Voice Mail integration
24
TSW Card
The KX-TD50104 TSW-CONF card provides 3party conferencing capability. This includes the
three DPITS integration features Two-way
Record, Two-way Transfer, and Live Call
Screening.
Each of these features requires the use of
conference circuit
25
TSW Card
The KX-TD50105 DOHCA card provides for
DPT OHCA by providing TSW circuitry to
support the second “B” channel for DPT
telephones and DPITS integrated voice mail
ports
The KX-TD50105 DOHCA card must be
installed for DPITS voice mail integration to
work
26
New KX-TD500 Cards
include:
 These cards will only operate in a KX-TD500
KX-TD50170-Digital Hybrid Line Card (DHLC)
KX-TD50172-Digital Line Card (DLC)
KX-TD50175-Enhanced Single Line Card
(ESLC)
KX-TD50180-Enhanced Loop Central Office
Trunk (ELCOT)
KX-TD50197-Enhanced Remote Card (ERMT)
27
KX-TD50170
Digital Hybrid Line Card
The DHLC supports 8 analog proprietary
telephones or 8 digital proprietary and 8
SLT telephones (XDP or parallel)
This card supports 7000 and 7400 series
telephones as well as SLT’s
See right side of page 2-41 in Installation
Manual for block wiring
28
KX-TD50170
Digital Hybrid Line Card
OHCA using the KX-T7436/7130 is
supported without any additional cards
installed on the station card. (The KXTD50105 card must be installed on the
TSW card for OCHA to the KX-T7436)
29
KX-TD50172
Digital Line Card
The DLC supports 16 digital proprietary
telephones (7400 series) and DSS
consoles
No SLT’s are will operate on this card
See right side of page 2-44 in Installation
Manual for block wiring
30
KX-TD50175
Enhanced Single Line Card
The ESLC supports 16 single line
telephones with Message Waiting Lamp
compatibility
No proprietary telephones will operate on
this card
ESLC has 4 DTMF receivers
See right side of page 2-42 in Installation
Manual for block wiring
31
KX-TD50180
Enhanced Loop CO Trunk
The ELCOT card supports 8 Loop Start
Central Office lines
When two optional KX-TD193 Caller ID
cards are installed, Central Office Caller ID
is provided to proprietary display
telephones
See page 2-55 in Installation Manual for
block wiring
32
KX-TD50197
Enhanced Remote Card
The ERMT card is a modem card (V.34)
used for remote administration.
33
Other Cards Supported by
the KX-TD500
The following cards were previously
supported by the KX-T336, and in the case of
the KX-TD193, the KX-TD816/1232, and
provide the same functions and capabilities.
Refer to KX-TD500 optional card
compatibility chart for more information
34
Other Cards Supported by
the KX-TD500
KX-T96170 - 8 Station Hybrid Line Card (HLC)
KX-T96172 - 8 Station Proprietary Line Card
(PLC)
KX-T96174 - 8 Station Single Line Card (SLC)
KX-T96175 - 8 Station Single Line Card with
Message Waiting Lamp compatibility (SLCM)
KX-T96180 - 8 Loop Start Central Office Trunk
card (LCOT)
KX-T96181 - 8 Ground Start Central Office Trunk
card (GCOT)
35
Other Cards Supported by
the KX-TD500
KX-T96182
KX-T96185
card (OPX)
KX-T96186
KX-T96187
KX-T96161
KX-T96191
KX-T96193
(AGC)
- 4 DID Trunk card (DID)
- 4 Station Off-Premise extension
-
Off Premise Extension Power Unit
T1 card (T1)
Doorphone card (DPH)
DISA card (DISA)
Automatic Gain Control card
36
Other Cards Supported by
the KX-TD500
KX-T96196 - 1200 bps Remote card (RMT)
KX-T96136 - OHCA card for HLC and PLC
cards (OHCA)
KX-TD193 - Caller ID card for ELCOT card
(CID)
37
KX-T96170
Hybrid Line Card (HLC)
Each card provides 8 Hybrid extension
ports
Either a Analog Proprietary Telephones
(7000 series) or a single line telephones
can be connected to this card
See right side of page 2-41 in Installation
Manual for block wiring
38
KX-T96172
Proprietary Line Card (PLC)
Each card provides 8 proprietary
extension ports
Only Analog Proprietary Telephones (7000
Series) can be connected to this card
See right side of page 2-41 in Installation
Manual for block wiring
39
KX-T96174
Single Line Telephone card (SLC)
Each card provides 8 single line extension
ports
Only single line telephones can be
connected to this card
See right side of page 2-41 in Installation
Manual for block wiring
40
KX-T96175
Single Line Card with Message Waiting
(SLC-M)
Each card supports 8 single line extensions
with Message Waiting lamps
See right side of page 2-41 in Installation
Manual for block wiring
41
KX-T96180
Loop Start Central Office Card (LCOT)
Each card allows 8 Loop Start Central
Office lines to be connected to the system
See page 2-55 in Installation Manual for
block wiring
42
KX-T96181
Ground Start Central Office Card (GCOT)
Each card allows 8 Ground Start Central
Office lines to be connected to the system
See page 2-55 in Installation Manual for
block wiring
43
KX-T96182
Direct Inward Dialing Trunk Card (DID)
Each card allows 4 DID Central Office
lines to be connected to the system
This card will accept pulse signaling only
System interface is modular (RJ-11C)
44
KX-T96185 and KX-T96186
KX-T96185--Off Premise EXtension Card (OPX)
KX-T96186--Off Premise Extension Power Supply
An OPX card and Power Supply provides 4 OPX
single line telephones only
Both OPX units are required when a single line
telephone must be placed in another building or
location
System interface is modular (RJ-11C)
45
KX-T96187
T-1 Card
Up to 8 T1 cards can be installed in the
KX-TD500
Frame Formats D4/SF or ESF
Line Coding
AMI or B8ZS
Channel Types
LCO/GCO/DID/OPX/TIE
System interface is RJ-48C (See page 253 in Installation Manual for cable
configuration)
46
KX-T96187
The T1 card can only be installed in slots
1 (2), 5 (6), and 9 (10).
The slot immediately adjacent to the right
of each T1 card must be left empty as
indicated above by the slot number that
are parenthesized.
47
KX-T96161
Doorphone card
Provides 4 Doorphones and 4 dry contact
relays
2 card per system
48
KX-T96191
Direct Inward Station Access card (DISA)
Each DISA card can be programmed to
provide one of three functions.
Basic 4 port automated attendant or;
Outgoing Message for Uniform Call
Distribution
Timed Reminder OGM
8 DISA cards can be installed in the
system
49
KX-T96193
Automatic Gain Control card (AGC)
Each card provides 4 gain controlled CO
to CO conference circuits
8 AGC cards can be installed in the
system
50
KX-T96196
Remote Administration card
Allows remote system administration at
1200 baud
1 Remote card can be installed in the
system
51
KX-T96136
KX-T96136 -- Off Hook Call Announce
card
1 KX-T96136 card must be installed for
every 2 KX-T7130 telephones that require
OHCA
A maximum of 4 KX-T96136 connects to
either the PLC or HLC cards
52
KX-TD193
Caller ID Card
1 KX-TD193 will support 4 Caller ID
compatible Central Office Lines connected
to the KX-TD50180 card (ELCOT). For all
eight lines to support Caller ID, a second
KX-TD193 must be installed.
The KX-TD193 supports both Single and
Multi-Message formats
53
System Construction
Maximum Configuration
Although the systems model number is
the KX-TD500, the actual maximum
system configuration can be 512 ports.
This port configuration cannot be
exceeded.
54
System Construction
Maximum Configuration
Things to remember about system configuration
512
448
192
216
192
128
160
ports/system is the maximum allowed
extensions/system is the maximum allowed
CO Lines/system is the maximum allowed
PT, SLT, & CO ports/expansion shelf
PT and SLT ext./shelf is the max. allowed
PT/Shelf is the maximum allowed
SLT/Shelf is the maximum allowed
55
System Construction
Basic Shelf
Review Installation Manual
Page 1-4 (see handout)
 Basic System
192 Lines (Ports)
Basic Shelf
14 Card Slots
2 Basic Slots
12 Free Slots
56
System Construction
Expansion Shelf
Review Installation Manual
Pages 1-5 (see handout)
System Expansion
Two Expansion Shelves Maximum
14 Free Slots per Expansion Shelf
216 Lines (Ports) Maximum per Expansion Shelf
57
System Construction:
Installation Manual:
Review Installation Manual
Pages 1-7, 1-8 and 2-36/39 (see handout)
Review number of ports per shelf / system
Review number of particular ports per shelf
8 Doorphones and 64 DSS Consoles per sys
Review Ports per particular Card
Review Ports per Special Cards
Review types of devices per Card
58
System Configuration
Example 1
Expansion Shelf 2
4 DLC x 16 ports =
4 LCOT x 8 ports =
6 FS for option cards
64 ports
32 ports
96 ports total
Expansion Shelf 1
8 DLC x 16 ports =
4 ESLC x 16 ports =
2 LCOT x 8 ports =
128 ports
64 ports
16 ports
208 ports total
Basic Shelf
8 DLC x 16 ports =
4 ESLC x 16 ports =
128 ports
64 ports
192 ports total
Final system configuration of (48) CO lines and (448)
extensions (320 DPT & (128) SLT) = (496) Total
59
System Configuration
Example 1
41 - 48 CO
= 6 LCOT (ELCOT)
305 - 320 DPT
= 20 DLC
113 - 128 SLT
= 8 ESLC
34 out of 40 Free Slots used
496 out of 512 ports used (16 avail.)
XDP, Parallel Telephones or APT require
DHLC
60
System Configuration
Example 2
Expansion Shelf 2 8 DLC x 16 ports = 128 ports
2 T1 x 24 ports =
48 ports
176 ports total
Expansion Shelf 1 5 DLC x 16 ports = 80 ports
3 T1 x 24 ports =
72 ports
152 ports total
Basic Shelf
3 DLC x 16 ports = 48 ports
3 T1 x 24 ports =
72 ports
120 ports total
Final system configuration of 192 T1 channels and 256
DPT extensions 448 Total
61
System Configuration
Example 2
169 - 192 T1 Channels = 8 T1
241 - 256 DPT
= 16 DLC
32 out of 40 Free Slots used
448 out of 512 ports used (64 avail.)
62
TD500 Upgrade from a
Duel Cabinet TD1232
Assignable Features to Button Differences
4 digit Extension Numbers
Parallel / XDP requires DHLC
2 External Paging Zones
100 Call Park Zones
PC Programming of Station Telephone
Settings
63
System Startup Procedure
System startup or initialization must be
executed for every system
The purpose of this procedure is to
default the system and to automatically
assign installed hardware into their
respective positions
This procedure is accomplished using
rotary switch labeled “Mode” on the CPU
card
64
System Startup Procedure
Mode switch positions are:
 Position
 Position
 Position
 Position
 Position
 Position
testing
 Position
testing
1
0,2,3,9
4
5
6
7
On-line while holding current data
On-line Same function as 1
Off-line holding current data
Off-line while defaulting system
ON-LINE with “backdoor” password
Off-line factory finished product
8
Off-line factory finished product
65
System Startup Procedure
Review Installation Manual
Page 2-78/80 and 2-79/81
Initializing system with default values
Mode SW Position 5, reset, then 0, reset
Loading system with saved data (Off-line)
Mode SW Position 4, reset, then Up-Load,
Mode SW position 0, reset
66
KX-TD500 Hardware
Addresses
The KX-TD500, like most other universal
free slot designed PBX’s, utilize a
numbering system to identify ports, cards,
and shelf locations.
This is necessary when programming and
maintaining the system
67
KX-TD500 Hardware
Addresses
Generally hardware address will be either
3 digit or 5 digit numbers.
Example: 10205
The first digit (1) indicates the shelf. In this
example the 1 indicates the Basic Shelf. The
first expansion shelf would be identified with
a 2 and the second expansion shelf identified
with a 3
68
KX-TD500 Hardware
Addresses
Example: 10205
The next two digits (02) indicate the slot
number. In this example the card is located in
the Basic Shelf in slot 2. In the Basic Shelf,
valid entries would be 01-12. In the
Expansion Shelves, valid entries would be 0114
69
KX-TD500 Hardware
Addresses
Example: 10205
The next two digits (05) indicate the port
number. Port number identifiers will vary
based on the card type. Some will have up to
16 ports, others 8 or less.
For example, a DLC is a 16 port card and
would have valid entries of 01-16.
70
KX-TD500 Hardware
Addresses
Example: 10205
A DHLC is slightly different. The first 8 port
identifiers (01-08) are used to identify the 8
proprietary ports on this card. The second 8
port identifiers (09-16) are used to identify
the XDP ports. For example, port identifier 09
is used to program the XDP single line
extension for port 01.
71
KX-TD500 Hardware
Addresses
A card with twenty-four port identifiers
(01-24) is the T1 card
Cards with sixteen port identifiers (01-16)
include: DLC, DHLC and ESLC
Cards with eight port identifiers (01-08)
include: HLC, PLC, SLC, SLC-M, LCOT,
GCOT & ELCOT
72
KX-TD500 Hardware
Addresses
Cards with four port identifiers (01-04)
include: OPX, DID, DISA, AGC & DPH
Cards that have no port identifier include:
RMT and ERMT
73
Port Status
Ports and cards can be in various states of
service
Operational devices are usually In-Service
or the abbreviation “INS”
Disabled devices are usually Out-ofService or the abbreviation “OUS”
Another state is Fault. This can be caused
by several things including configuration
problems as well as hardware failure
74
Port Status
The final state of service is called Busyout. This occurs on CO ports that have
been placed in the Busy-out state by a
system administrator.
Generally the “INS” and “OUS” states are
most common. Changing from one to
another is accomplished by using different
screens from within the KX-TD500
Maintenance Console programming tool
75
Port Status
Within the Maintenance Console
programming tool, the state of service can
be identified and changed by clicking on
the “Status” button. The text on the
“Status” button indicates the current
state, and the state can be toggled from
one state, for example OUS, to the
alternative state, in this case INS, by
clicking on the “Status” button and then
selecting OK.
76
Port Status
What is T1?
T1 is the telephone companies infrastructure
(copper wire, transmission equipment,…)
that provides a high speed digital telephone
circuit between two points.
T1 circuits operate at a rate of 1.544 Mbps
or at what is referred to as DS1
A DS1 is comprised of 24 64 Kbps* channels
(DS0) plus framing overhead
* Certain line code and frame selections can reduce the available bandwidth from 64 to 56 Kbps
80
T1
channels
24
bits per word
x8
bits
192
samples/sec
x 8000
user data 1,536,000 bps
frame bits
+ 8000
line speed 1,544,000 bps
81
Digital Trunking
T1 Channel Service Unit
T1 demarc at customer premise
PSTN:
Local Exchange Carrier (LEC)
or
Interexchange Carrier (IEC)
TD500 equipped with KX-TD97187
82
T1 Channel Service Unit
A T1 Channel Service Unit (CSU) is
required for each T1 line that is to be
connected to the KX-TD500
For a basic TD500 T1 installation, only a
CSU is required.
CSU’s come in a variety of configurations
based on the application and prices will
vary.
83
T1 Channel Service Unit
CSU Functions:
It is the first piece of Customer Premise
Equipment (CPE) after Telco’s demarcation point.
Provides a 100 Ω circuit termination
Provides FCC Part-68 protection
Initiates and facilitates loopback testing
Monitors line for errors and violations
Maintain 0’s and 1’s density
Supports Line Coding and Framing requirements
84
Adtran ESF T1 CSU ACE
Full featured T1 CSU suitable for wall or
desktop use.
Front panel LCD and four user keys provides
easy configuration and unit monitoring
Physical Interface RJ-48C
Supports D4/SF or ESF
Supports AMI or B8ZS
85
What is D4/SF and ESF?
Superframe (SF) or D4, and Extended
Superframe (ESF) are the two frame
formats used in North America.
Frame formats are used for frame
synchronization and also for line
management tasks
The KX-TD500 supports either frame
formats
86
D4/SF
D4 or Superframe was introduced in 1974.
The D4 was derived from the first Telco
channel bank which utilized this type of
frame formatting.
D4/SF framing consists of a superframe
made up of twelve individual frames
The twelve framing bits within the
superframe follow a pattern of
100011011100
87
D4/SF Superframe
Superframe
F1
F2
F3
F4
F5
Frame 1
F6
F7
F8
F9
F10
F11
F12
Frame 2
F Ch1 Ch2 ……... Ch24 F Ch1 Ch2 ……... Ch24
0 1
0
0
1
Word
0
1
1
0
Frame 2 framing bit
88
D4/SF
D4 or SF framing uses an in-band call control
method called “bit robbing” which robs the
least significant bit from each of the 24
channels within the 6th and 12th frame.
This call control information is used for
dialing and other line maintenance functions.
This frame format restricts the channel
bandwidth to 56 Kbps rather than 64 Kbps
and is used most often in voice applications.
89
Extended Superframe
(ESF)
Extended Superframe is the preferred
method of framing since it utilizes a larger
number of frames (24 frames) and
requires fewer framing bits to maintain
synchronization
Framing bits for frames 4, 8, 12, 16, 20,
are set to the pattern of 001011 that the
far end equipment synchronizes on.
90
Extended Superframe
(ESF)
Since fewer frames require framing bits,
the excess framing bits for the other
frames can be used for other functions
such as Cyclic Redundancy Checks and for
an Embedded Operations Channel
The Embedded Operation Channel is an
Out-of-Band call control method used for
signaling, dialing, diagnostics as well as
other functions.
91
Extended Superframe
Extended Superframe
F1
F2
F3
F4
C
F5
F6
F8
F9
C
E
F10
F
E
F11
F12
C
F
E
F7
E
E
F14
C
F
E
F13
E
F15
F
E
E = Embedded Operations channel bit
C = Cyclic Redundancy Check bit
F = Framing bit
Only 15 of the 24 frames are shown
92
Extended Superframe (ESF)
ESF should be used whenever possible since
it has a more sophisticated diagnostic and
maintenance capability and allows for a 64
Kbps channel bandwidth.
93
What is AMI and B8ZS?
Alternate Mark Inversion and Binary 8 Zero
Substitution are the two Line Coding
formats used in North America for T1 lines
The purpose of Line Coding is to maintains
synchronization by ensuring that no more
than 7 consecutive “0’s” are transmitted
within a DS0.
94
Signaling Formats
Unipolar Signaling
Used internally within most DTE equipment
such as the KX-TD500 and computers
+5 v
0
1
1
0
0
1
0
0
0v
Bipolar Alternate Mark Inversion
T1 lines utilize this type of signaling format
+3 v
0
1
1
0
0
1
0
0
0v
-3v
95
AMI Line Coding
AMI get around the 1’s density
requirement by forcing a 1 into the bit
stream or what is called “bit stuffing.” The
CSU accomplished this task by inserting a
1 into the least significant bit location.
The draw back to this method is that it
reduces the available user bandwidth to
56 Kbps
96
AMI Line Coding
+5 v
DTE Sends
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
1
Ov
-5 v
CSU set
for AMI
sends
+5 v
Ov
-5 v
97
B8ZS Line Coding
Binary 8 Zero Substitution is the most
popular Line Coding technique used in
North America.
B8ZS uses a method of inserting a
particular bit pattern which includes
intentional bipolar violations to replace a
series of 8 “0’s”
This is the preferred Line Coding
technique since it allows for 64 Kbps
98
B8ZS Line Coding
+5 v
DTE Sends
1
0
0
0
0
0
0
0
B
0
0
0
B
1
0
Ov
-5 v
Previous Word
CSU set
for B8ZS
sends
+5 v
1
1
0
Ov
-5 v
B = Bipoalar Violation
99