IBM 2702 Technical manual

Systems R.eference Library
IBM 2702/2703 Transmission Controls
Original Equipment Manfacturers' Information
File No. 8360-19
Form A27-3012-0
This publication describes the IDM 2702/2703 Transmission
Control interfaces. The processor interface description
includes a description of the operating signals and responses.
The interface descriptions provide device attachment infor-
mation. The electrical, mechanical, and cabling specifications
of these interfaces are provided, together with physical planning
requirements.

PREFACE
This manual references information contained in the
System/360 I/O Interface Original Equipment Manufac-
turer's Information Manual, Form A22-6843.
Unless otherwise stated, the grounding of various
external devices to the 2702/2703 is made at the power
source common. However, when the power sources
differ (thus allowing the frames of different machines
to be at different potentials) and when the machines
are close enough to one another to present a hazardous
condition, other grounding methods must be used. In
no case should interface lines designated as grounds
be used to establish a common frame grounding.
First Edition, February 1968
Significant changes or additions to the. specifications contained in this
publication are continually being made.. When using this publication
in connection with the operation of IBM equipment, check the latest
SRL Newsletter for revisions or contact the local IBM branch office.
The data contained herein is current as February 16, 1968.
Requests for copies of IBM publications should be made to your IBM
representative or to the IBM branch office serving your locality.
A form is provided at the back of this publication for the reader's
comments. If the form has been removed, comments may be ad-
dressed to IBM Corporation, Systems Development Division, Product
Publications, Dept. 860, P. O. Box 12275, Research Triangle Park,
North Carolina 27709.
ii

CONTENTS
CHAPTER 1. INTRODUCTION
..
1-1
Timeouts. 2-42
Features
1-3
IBM Telegraph Line Adapter - Operations.
2-42
2702 Features 1-3 'fransmission-Code Error Detection Employed.
2-42
2703 Features
1-4
Modes of Operation 2-45
Communications Facilities 1-6
Timeouts 2-45
Addressing 1-6
IBM World Trade Telegraph Terminal Control
2-45
Transmission Code.
2-45
CHAPTER 2. OPERATIONS
2-1
Special Characters
2-45
2702 Operator's Panel
2-1
Line Cont rol .
2-47
Operator Switches 2-1 Timeouts
2-47
Operator Panel Indicators 2-1
Message Restrict ion
2-48
2702 CE Panel 2-3
Telegraph Terminal Control Type I -
Operations
2-48
CE Panel Switches
2-3
Transmission Code
2-48
CE Panel Indicators 2-7 Special Charact ers
2-48
2703 Operator's Panel. 2-10
Terminal-to-Terminal Operation with Search
Operator Panel Switches 2-10 Command
2-50
Operator Panel Indi cators 2-10
Timeouts
2-50
2703 CE Panel 2-10
Message Restrictions
2-50
CE Panel Switches 2-10 Telegraph Terminal Control Type II -Operations
2-52
CE Panel Indicators
2-10 Transmission Code.
2-52
Metering 2-10
Special Charact ers
2-52
Metering with the TPS Feature.
2-11
Binary Synchronous Communications (BSC)
2-53
Reset 2-11
System/360 1/0 Interface. 2-26
CHAPTER 3.
COMMUNIcATIONS INTERFACES
3-1
Data Bytes 2-26
Int erface Line Descript ions .
3-1
'Status Byte 2-26
EIA RS232B Interface Description
3-1
Sense Byte
2-29
Automatic Calling Unit Interface
3-3
Interface Stop Signal. 2-29
2702/03 Line Adapters .
3-5
Halt 1/0 (Interface Disconnect Signal)
2-29
IBM Line Adapter.
3-5
Commands • 2-29
Telegraph Line Adapter
3-5
Control-Type Commands. 2-29
Data-Set Line Adapters
3-5
Transmit-Type Commands 2-35
2702/03 Auto Call Feature. 3-9
Receive-Type Commands. 2-38
IBM Terminal Control Type I - Operations 2-39
CHAPTER 4.
EXTERNAL cABLING 4-1
Transmission Code
2-39
Cable Requirements 4-1
Special Characters
2-40
Serpent Contacts. 4-1
Modes of Operation
2-41
Cables
4-1
Emergency Power Off (EPO) Cabling
4-1
iii

Figure
Page
1-1 Data Communication Units Attachable to
2702/2703 1-2
1-2
At t achable Terminals and Comm unica t ion
Facilities for Domestic Use
1-7
1-3 Attachable Terminals and Communication
Facilities for World Trade Use. 1-10
1-4 Addressing Scheme.
1-11
2-1
2702/2703 Commands 2-2
2-2
2702 Operator Panel
2-3
2-3
2702 Operator Panel with TPS and 2712 Features 2-4
2-4
2702 CE Panel 2-5
2-5
2703 Operators Panel with TPS and 2712 Feature
2-11
2-6 2703 CE Panel 2-13
2-7 CE Panel Roller Indicators •
2-17
2-8 Status Bits 2-26
2-9 Ending Status CE, DE, and UE
2-27
2-10 Ending Status on Halt I/O • 2-28
2-11 Sense Bit 0, Command and Reject 2-30
2-12
Sense Bit 1, Intervention Required 2-30
2-13
Sense Bit 2, Bus-Out Parity Check 2-31
2-14 Sense Bit 3, Equipment Check 2-31
2-15 Sense Bit 4, Data Check 2-32
2-16
Sense Bi t 5, Overrun
2-32
2-17 Sense Bit 6, Lost Data Set by Common
Controls
2-33
2-18
Sense Bit 7, Timeout Complete 2-34
2-19 Dial Digits in System/360 Byte Structure
2-37
2-20
IBM Terminal Control Type I Transmission Code
2-40
2-21
IBM Terminal Control Type I Transmission to
Int erface Conversion •
2-40
2-22
Special-Character Configuration
2-40
2-23 Sample Message Sequence
2-42
2"24
IBM Terminal Control Type II Transmission
Code
2-44
2-25 TC-n Transmission to Int erface Conversion
2-44
2-26
Special Charact er Configuration
2-44
2-27 Sample Message Sequence
2-46
2-28
Baudot Transmission Code
2-46
2-29
Transmission Code Conversion to Interface Code
2-46
2-30
Special Characters
2-46
2-31
Baudot Transmission Code
2-49
2-32
Transmission Code Conversion to Interface Code
2-49
Table
Page
2-1
Correlation of Load Line Ctl Word Switch with
LCW Segments
2-7
2-2
Clock Ring Indicators
2-8
2-3
Operator Panel Switches
2-12
2-4 Operator Panel Indicators
2-13
2-5 CE Panel Switches.
2-14
2-6
CE Panel Indicators 2-18
iv
ILLUSTRATIONS
Figure
Page
2-33
Special Charact ers
2-49
2-34
Telegraph Terminal Control Type I with AT&T
83B2/83B3
or Western Union Plan 11SA
Terminals
2-51
2-35
TWX Transmission Code
2-52
2-36
Transmission Code Conversion
2-52
2-37 TWX Special Characters
2-53
3-1 Data Set Interface-(Start/Stop) 3-2
3-2
2712 Feature Data Set Interface 3-2
3-3
Automatic Calling Interface
3-4
3-4 Automatic Calling Unit Interface Pin Circuit
Designations
3-4
3-5
2702 Telegraph Line Adapter 3-6
3-6
2703 Telegraph Adapter
3-7
3-7
2702 Data Set Line Adapter #3233 Plugged for
Switched Network, Full Duplex
3-8
3-8
2702 Data Set Line Adapter #3233 Plugged for
Private Line, Full Duplex.
3-10
3-9
Input Line Characteristics •
3-11
3-10
Out put Line Charact erist ics
3-11
4-1 2702/2703 Cables.
4-2
4-2 Connector Blocks and Contact Location
4-2
4-3 Serpent Cont act
4-3
4-4 2702/2703 Cable Connectors
4-4
4-5
2702/03 to System/360 Cables
4-5
4-6
2702/03 EPO Cable
4-6
4-7
2702 Data Set Cable (Group No. 403); 2703 Data
Set Cable for 2712 (Group No. 428)
4-7
4-8 Group 404-Domestic TTY
4-8
4-9 Group 405-Customer Owned Comm.
Line Cable
4-9
4-10
Group 406-WTC Teletype Cable
4-10
4-11
Group 408-Data Set Cable.
4-11
4-12
Group 409-Domestic Teletype (2702)
4-12
4-13
2702/3 IBM Limited Distance Line Adapters
Type lA, 1B and 2703 Type 2B to Line
Connection.
4-13
4-14
2703 to Data Set (Group 424); 2703 to 2711
(Group 442) •
4-14
4-15
2703 to Telegraph Lines (Group No. 425) •
4-15
4-16
2703 to Auto Call Data Set (Group No. 427) •
4-16
4-17
2703 to (Synchronous) Data Set (Group
No. 429)
4-17
TABLES
2-7 Meter Operation Under Various TPS Conditions
3-1 Length of Timeout Sequence for 2702 Read-Type
Commands •
4-1 2702 Cable Data
4-2 2703 Cable Data
2-25
3-10
4-18
4-19

The IBM 2702/2703 Transmission Control Units:
III Permit combining data processing and data com-
munications.
• Direct and control data flow between the processor
and remote terminals.
o Operate in byte-interleaved mode.
Also:
• The 2702 can operate from 1 to 31 half-duplex
lines.
(ll The 2703 can operate from 1 to 176 half-duplex
lines.
G The 2702 provides speeds up to 180 bps, or up to
600 bps with added features.
Cl The 2703 provides speeds up to 600 bps, or up to
2400 bps with added features.
In addition, the 2702/2703:
e Receives and transmits data serially by bit.
o Transfers data to and from channel by byte.
QII Does not restrict message length.
The 2702/2703 Transmission Control Units (from
now on referred to as multiplexers) provide for the
on-line attachment of various I/o devices via private
and commercial common-carrier communications
facilities to a channel that conforms to the standard
IBM System/360 I/o Channel Interface (Figure 1-1).
Data communications equipment that can be attached
to the multiplexers inclUde the following:
IBM 1030
Data Collection System.
IBM 1032 Digital Time Unit (2702 only).
IBM
1050 Data Communication System,
IBM 1060 Data Communication System.
IBM 1070 Process Communication System.
IBM 2712 Remote Multiplexer, Models 1 and 2,
IBM
2740 and 2741 Communications Terminals.
CHAPTER 1. INTRODUCTION
AT&T
83B2/83B3 Type Selective Calling Ter-
minals.
Western Union Plan 115A Terminals.
Common Carrier TWX Stations (8-level code).
European Teleprinters (World Trade attachments).
Another IBM System/360 via an IBM 2701 Data
Adapter Unit equipped with appropriate Syn-
chronous Features (2703 only).
Another IBM System/360 via an IBM 2703 Trans-
mission Control equipped with the appropriate
Synchronous Features (2703 only).
IBM
2780 Data Transmission Terminal (2703 only),
IBM 1130 Computing System equipped with the
Synchronous Communications Adapter feature
(2703 only).
Each multiplexer occupies one of eight allowable
control-unit positions in a multiplexer channel. Data
transfers between the multiplexers and the multi-
plexer channel are in the byte-interleaved mode,
each byte consisting of eight data bits and one parity
bit.
Each multiplexer is flexible in line capacity, trans-
mission code, and speed. The basic 2702 can have
15 half-duplex lines and operates at speeds up to
134.5 bps for any or all attached communications
lines. (Optional features enable the 2702 to operate
up to 15 lines in a start-stop mode at transmission
rates up to 600 bps.) The 2703 can operate 1 to 176
half-duplex lines at speeds up to 134.5 bps for any
or all attached communications lines (as an optional
feature up to 72 lines at 600 bps). Optional features
available enable the 2703 to operate in a synchronous
mode at transmission rate up to 2400 bps.
On input messages (data being sent to the channel),
the mUltiplexer accepts data serially by bit from the
remote terminal via the communications line, assem-
bles this data into characters and transfers the char-
acters serially to the channel. On output messages
(data being sent to the mUltiplexer from the channel),
the multiplexer accepts the data serially by byte and
transfers it serially by bit to the remote terminal.
The multiplexer does not impose restrictions on
message length. All 2702/2703-channel message
buffering is done by the processor. All necessary
bit-byte conversion, data control, and signal match-
ing to common-carrier equipment are accomplished
by the multiplexers.
Introduction 1-1

IBM 2780*
IBM
1050
IBM 1060
IBM 2712
IBM 1070
IBM 2740 or 2741
Figure 1-1. Data Communication Units Attachable to the 2702/2703
1-2
IBM 1130*
2702
or
2703
o
1M:I;p~:-e~ . Processor
IChannel r
L _____ -'
* Connects only to 2703
** Connects only to 2702

FEATURES
2702 Features
The following features provide expanded capability
for the IBM 2702 in terms of line speed, number of
lines, and other functions.
Speed Extension Feature. Enables the 2702 to oper-
ate at speeds up to 600 bps on all 15 lines.
31- Line Expansion Feature. Expands the line handl-
ing capabilities of the 2702 to 31 half-duplex lines at
134.5 bps. The 31-Line Expansion feature and the
Speed Extension feature are mutually exclusive--that
is, either feature may be selected, but not both.
Auto Call Feature. Provides the 2702 with automatic
dialing capability of up to S communications-line
attachments.
Auto Call Expansion Feature. Expands the automatic
dialing capability of the 2702 up to 16 communications-
line attachments. The Auto Call feature is a prere-
quisite.
Auto Call Adapter Feature. Matches the interface of
the common-carrier Automatic Dialing Unit; the Auto
Call feature is a prerequisite. The Auto Call Adapter
provides for attachment of the 2702 to private or
common-carrier switched networks, via Western
Electric Automatic Calling Unit SOlA1 or SOlC2. A
maximum of 16 Auto Call Adapters can be chosen
for one 2702 when the Auto Call ExpanSion feature
is installed. One adapter is required for each auto
call line. The Auto Call feature is a prerequisite.
Two- Processor Switch Feature. Enables the 2702 to
be physically attached to the multiplexer channels of
two System/360 processors. The 2702 must be in a
neutral state for the switching to occur. When in
this neutral state, the 2702 monitors both multiplexer
interfaces and automatically switches and locks to the
first channel addressing any line of the 2702. The
attached processor can return the switch to neutral
under program control or through a manual reset.
Data Set Line Adapter. Allows attachment to the fol-
lowing:
a. IBM 2711 Line Adapter.
b. Western Electric Data Set 103A* for operation
at 134.5 bps on Common Carrier Switched
Telephone or 150 baud TWX networks.
*Or equivalent (see Chapter 3) .
c. Western Electric Data Set 103F2* for operation
at 134.5 bps on Telephone Company Type
3002 Private Line Service.
d. Suitable channel termination for operation on
Telephone Company Type 1006 (150 baud)
Channels.
e. Western Union Data Loop Transceiver 11S3A*
on Western Union Class D (ISO baud) Channels.
f. Western Electric Data Set (202Dl* for operation
on Telephone Company Type 3002 Channels or
Western Union Class G channels for 600 bps
operation.
IBM Line Adapter. Two types are available:
a. Limited-Distance Line Adapter Type I--Allows
attachment to privately owned or leased com-
munication networks of 4. 75 wire miles or less
length. With this feature, a data set is not
needed. Up to 25 adapters can be mounted in
the 2702 unit; additional adapters require the
use of an IBM 2711 Line Adapter Unit.
b. Limited-Distance Line Adapter Type II--Allows
attachment to privately owned or leased com-
munication networks of S wire miles or less
length. With this feature, a data set is not
needed. A maximum of 15 adapters (16 with
the 3l-Line Expansion feature) can be attached.
IBM Terminal Control Type 1. Enables the 2702 to
operate with the IBM 1050, 1060, and 1070 systems
or the IBM 2740 and 2741 terminals. Three speeds
are available:
75 bps
134.5 bps
600 bps
Connection
IBM 1050 on telegraph lines
IBM 1050, 1060, 1070, 2740 Mod 1, or
2741
IBM 1070, 2740 Mod 2
IBM
Terminal Control Type II. Enables the 2702 to
operate with the IBM 1030 Data Collection System
(1031A Input Station and 1033 Printer) or the IBM
1032
Digital Time Unit at a speed of 600 bps.
Telegraph Line Adapter. Allows attachment to Com-
mon Carrier Leased Private Line Telegraph Service.
Channels that can be attached are Telephone Company
Type 1002 at 45.5 or 56.9 bps, Type 1005 at 74.2
bps, and Western Union Class A, B, and C Channels
at 45.5, 56.9, and 74.2 bps, respectively. A maxi-
mum of 15 lines is allowed; with 31-Line Expansion
feature, 31 are allowed.
Introduction 1-3

Telegraph Terminal Control Type 1. Enables th~
2702 to operate with the AT&T 83B2/83B3 Selective
Calling Terminal or the Western Union Plan 115A
terminal. Three speeds are available:
45.5 bps
56.9 bps
74.2 bps
Facilities
Telephone Company Type 1002 Chan-
nels or Western Union Class A
Channels
Telephone Company Type 1002 Chan-
nels or Western Union Class B
Channels
Telephone Company Type 1005 Chan-
nels or Western Union Class C
Channels
Telegraph Terminal Control Type II. Provides con-
trols for the attachment of Telephone Company Tele-
typewriter Exchange (TWX) Stations to the 2702.
Control is point-to-point over Common Carrier
Switched 150 baud TWX Service. Transmission
speed is 110 bps.
Terminal Control Expansion. Required if both IBM
and Telegraph terminals are to be attached to the
same 2702.
Additional Selective Speed Feature. Provides ability
to add an additional selective speed with IBM Ter-
minal Control Type I, Telegraph Terminal Control
Type I, and World Trade Telegraph Terminal Con-
trol. This feature allows one terminal control as-
signable within a 2702 to operate different lines at an
additional line rate (speed). For example, IBM
Terminal Control Type I could operate IBM 1050,
1060,
and/or 1070 terminals at 134.5 bps and 1070
terminals at 600 bps on the same 2702, but not on
the same communications line. Up to two Additional
Selective Speed features can be associated with one
terminal control, allowing it to handle three speeds.
The Additional Selective Speed feature can be associ-
ated with only one terminal control.
World Trade Telegraph Terminal Control. Enables
the 2702 to operate with various European teleprinters
over single-current or double-current telegraph lines.
Speeds are 50 and 75 bps. (Only one speed may be
selected without an Additional Selective Speedfea-
ture.) The World Trade Terminal Control and the
Telegraph Terminal Control Type I are mutually
exclusive; that is, either feature may be chosen but
not both. An IBM 3945 is required to interface with
the telegraph line adapters controlled by this terminal
control.
1-4
Remote Switch Attachment. Used with a System/360
Model 65MP or Model 67 to provide partitioning and
the ability to attach the Two-Processor Switch feature
to the Multisystem features (#4951, #4952) on the
65MP or on the 2167 Configuration Unit.
2712 Line Adapter. Provides the interface between
the 2702 common controls and the 2712 Modell or
Model 2 Adapter feature. One is required for each
line operating with the IBM 2712 Remote Multiplexer.
IBM 2712 (Models 1 and 2) Adapter. These adapters
are used in conjunction with an IBM 2712 Remote
Multiplexer. The Remote Multiplexer is a freestand-
ing unit located at the remote communications point.
It allows up to 10 lines operating at 134.5 bps or 14
lines operating at 74.2 bps to be bit-multiplexed onto
one high-speed full-duplex communications line.
Models 1 and 2 of the 2712 Adapter perform demulti-
plexing and bit-multiplexing of the 10-line and 14-line
signals, respectively.
1032 Attachment Feature. Allows the IBM 1032
Digital Time Unit to be attached to line 1 of the 2702,
provided an IBM Terminal Control Type II, a Speed
Extension feature, and a Data Set Line Adapter or
IBM Line Adapter are available. Upon being polled,
the 1032 provides time data at 600 bps (60 cps) to the
CPU.
IBM 2741 Break Feature. Provides for attachment
of the IBM 2741 CommuniCations Terminal with Inter-
rupt feature in timesharing and other applications ..
Isolation Feature. Allows power to be turned on or
off in the 2702 without generating spurious I/O chan-
nel signals.
2703 Features
The 2703 does not have anyone basic model. Certain
major functional units of the 2703 (the line base, line
set, and terminal control) must be ordered to fit the
customer's line configuration. However, there must
be at least one line base, line set, and terminal con-
trol.
The following are the features that are provided in
the 2703. They are divided according to line base,
line set, terminal control, and special features.
Line Base Features
Start/Stop Base Type I. Allows attachment to the
2703 of up to 88 half-duplex lines operating at speeds
up to 165 bps.

Start/Stop Base Type II. Allows attachment to the
2703 of up to 24 half-duplex lines operating at speeds
up to 600 bps.
Synchronous Attachment. Allows attachment of
synchronous communications lines to the 2703. A
prerequisite to this feature is that the Base Expansion
feature be installed.
Synchronous Base Type 1A. Allows attachment to the
2703 of 24 half-duplex lines using Synchronous Ter-
minal Control for EBCDIC or USASCII. A prerequi-
site to this feature is the Synchronous Attachment
feature.
Synchronous Base Type lB. Allows attachment to the
2703 of 16 half-duplex lines using Synchronous Ter-
minal Control for 6-Bit Transcode. A prerequisite
to this feature is the Synchronous Attachment feature.
Base Expansion. Allows attachment of a Synchronous
Attachment feature or more than one Start/Stop Base
Type I or Type II feature to the 2703. Only one Base
Expansion feature can be used at one time.
Terminal Control Features
IBM Terminal Control Base. Allows attachment to
the 2703 of an IBM Terminal Control Type I and/or
Type II feature. A prerequisite to this feature is the
Start/Stop Base Type I feature.
IBM Terminal Control Type I. Allows attachment of
the IBM 1050, 1060, 1070, systems or the IBM 2740
and 2741 terminals to the 2703. A prerequisite to
this feature is the IBM Terminal Control Base fea-
ture. Three speeds are available:
Connection
75 bps IBM 1050 on telegraph lines
134.5 bps IBM 1050, 1060, 1070, 2740, or 2741
600 bps IBM 1070
IBM 2741 Break. Allows attachment of the IBM 2741
Communications Terminal with Interrupt feature.
IBM Terminal Control Type II. Enables the 2703 to
operate with the IBM 1030 Data Collection System at
a speed of 600 bps.
Telegraph Terminal Control Base. Allows attach-
ment of a Telegraph Terminal Control Type I or Type
II to the 2703.
Telegraph Terminal Control Type I. Enables the
2703 to operate with the AT&T 83B2/83B3 Selective
Calling Terminal or the Western Union Plan 115A
terminal. Three speeds are available:
45.5 bps
56.9 bps
74.2 bps
Facilities
Telephone Company Type 1002 Chan-
nels or Western Union Class A
Channels
Telephone Company Type 1002 Chan-
nels or Western Union Class B
Channels
Telephone Company Type 1005 Chan-
nels or Western Union Class C
Channels
Telegraph Terminal Control Type II. Provides con-
trols for the attachment of Telephone Company Tele-
typewriter Exchange (TWX) Stations to the 2703.
controi is point-to-point over common c-arrier
switched 150 baud TWX Service. Transmission
speed is 110 bps.
Telegraph Attachment. Allows attachment of Tele-
graph Line Set feature to the 2703. This feature is
required when one or more AT&T 83B2/83B3,
Western Union Plan 115A, IBM 1050, or IBM 2740
Model 2 are attached to the 2703 via the Telegraph
Line Set.
Synchronous Terminal Control. Allows attachment of
synchronous terminals to the 2703. It is available
for communicating in three different codes:
(1) EBCDIC; (2) USASCII; and (3) SBT.
Station Selection. This feature is required when one
or more lines are assigned to a Synchronous Ter-
minal Control that is functioning on a leased commu-
nications line as a terminal station or as a combina-
tion terminal and control station.
Line Set Features
Data Line Set. Allows attachment of up to eight lines
of terminals (IBM 1030, 1050, 1060, 1070, 2740,
2741, and Common Carrier TWX terminals Model
33/35 type) using facilities such as switched and
leased telephone networks, TWX, Western Union
Class D (180 baud) and Class E Channels, and
Telephone Company 150 baud Type 1006 Private
Line Service, or for attachment of up to eight lines
to the IBM 2711 Line Adapter Unit.
Intr oduction 1-5

Data Line Set Expander. Permits attachment of up
to eight additional lines to the Data Line Set feature.
IBM Line Set 1A. Allows attachment to the 2703 of
up to eight half-duplex lines with 2740/2741 terminals.
Used for two-wire local use (up to 4.75 wire miles).
IBM Line Set lB. Allows attachment to the 2703 of up
to eight half-duplex lines with 2740/2741 terminals.
Used for four-wire local use (up to 4.75 wire miles).
IBM Line Set 2. Allows attachment to the 2703 of up
to eight half-duplex lines with IBM 1030's, 1050's,
1060's, 1070's, 2740's or 2741'so Used for two-wire
local use (up to 8 wire miles).
Telegraph Line Set. Allows attachment of up to eight
lines via common-carrier private-line telegraph
service--such as Telephone Company Type 1002
(45.5 and 56.9 bps) and Type 1005 (74.2 bps) Private-
Line Service, and Western Union Class A, B, and C
Channels. AT&T 83B2/83B3 and Western Union Plan
115A terminals at 75 bps and IBM 1050 or 2740
Model 2 terminals can be connected to the 2703 using
this feature.
Telegraph Line Set Expander. Allows attachment of
up to eight additional lines to the Telegraph Line Set
feature.
Synchronous Line Set. Allows attachment of up to
four synchronous lines using voice-grade facilities.
Allows IBM 2701 's and IBM 2703's with System/360
processors, or System/360 Model 20 and IBM 1130's
with appropriate communications adapters, and IBM
2780's to be connected to the 2703.
Synchronous Clock. Required when attachment of
Western Electric Data Sets 202C1 or 202D1 are used.
Allows attachment to the 2703 of up to four such data
sets.
Special Features
This group of features can be divided into five classi-
fications: (1) Line-Speed Options; (2) Auto Call;
(3) 2712 Attachments; (4) Two-Processor Attach-
ment; and (5) Isolation.
Line Speed Options. These features provide the
attachment of the various synchronous and asynchro-
nous terminals with the following speeds:
1-6
Asynchronous
45.5 bps
56.9 bps
74.2 bps
75 bps
110 bps
134 bps
600 bps
Synchronous
600 bps
1200 bps
2400 bps
Autocall. Provides the 2703 with automatic dialing
capabilities for up to eight communications line
attachments.
2712 Attachment Features. These include:
1. 2712 Attachment--Needed for any 2712 lines.
2. 2712 Modell Adapter--Allows attachment of
up to eight 2712 Modell lines.
3. 2712 Modell Expander--Allows an additional
ninth and tenth line to the 2712 Modell Adapter
feature.
4. 2712 Model 2 Adapter--Allows attachment of
up to eight 2712 Model 2 lines.
5. 2712 Model 2 Expander--Allows an additional
ninth through fourteenth 2712 Model 2 line.
Two-Processor Switch Feature. Enables the 2703 to
be physically attached to the multiplexer channels of
two System/360 processors. The 2703 must be in a
neutral state for the switching to occur. When in this
neutral state, the 2703 monitors both multiplexer
interfaces and automatically switches and locks to the
first channel addressing any line of the 2703. The
attached processor can return the switch to neutral
under program control or through a manual reset.
Isolation Control Unit. Allows power to be turned on
or off in the 2703 without generating spurious I/o
channel signals.
COMMUNICATIONS FACILITIES
Figures 1-2 and 1-3 show the communic~tions facili-
ties used with the 2702/2703, the data set used for
attachment of each terminal, the operating speed, and
features required.
ADDRESSING
As previously mentioned, the multiplexers appear as
control units to the IBM I/o channel interface. Up to

Terrr.inal
Communication Foci Iity Terminal Dota Set*
Data Set*
Speed
Prerequisites
1050 Data Communication System
1051 Control Unit
Modell or 2 Common
Carrier Switched Western E! ectdc Western Electric
134. 5 bps
IBM Terminal ContTol Type I
Telephone Network 103A2 103A2
Selective Speed
Common Carrier Switched (150 Baud)
Western Electric
Western Electric
14.8 Char/Sec
Dota Set Line Adapter
Teletypewriter Exchange (TWX)
Network
103AI 103AI (One per Line)
Common Corrier Leased Private Western Electric Western Electric
Line Telephone Service 103F2 103F2
Western Union Class 0 (180 Baud)
Western Un ion Western Union
Channe I Doto
Set 1183A Data Set
1183A
Telephone Company
An Appropriate Channel
Type 1006 Termination Provided
Data Channel ~ (150 Baud) by Telephone Company
1051 Control Unit
Modell or 2
Telephone Company Type J005
75.0 bps
IBM Terminal Control Type 1
with Telegraph Attachment ·#7873
or Western Union Class C Channels Not Required
Not Required
Selective Speed
8.33 Cho,/Sec
Telegraph Line Adapter
(62.5 ma Neutral Signal) (One
De, Line\
1051 Control Unit Model 1 or 2 Common
Carrier Leased Private Line
134.5 bps
IBM Terminal Control Type I
with Line Adapter #4790
Telephone or Privately Owned Two
Not Required Not Required
Selective Speed
Wire Communication Facilities
14.8 Cho,/Sec
IBM Line Adopte, (#4612)
Conforming to SRL Manual A24-3435
(One per Line)
for Limited
Distance Line Adapter II.
1060 Data Communication System
1061 Control Unit Modell or 2
Telephone Company Type 3002
Western Electric Western Electric
134.5 bps
IBM Terminal Control Type I
Private Line Service.
I03F2 103F2
Selective Speed
Western Union Class 0 (180 Baud) Western Union Western Union
14.8 Chm/Sec Data Set Line Adapter
Channel
Data Set II 83A Data Set
II 83A (One per Line)
Telephone Company An Appropriate Channel
Type 1006
Termination Provided
Data Channels (150 Baud)
by Telephone Company
1061 Control Unit Model
1 or 2 Common Carrier Leased Private Line
with Line
Adapter #4790
Telephone or Privately Owned Two
Not Required NotRequired
134.5 bps
IBM Terminal Control Type I
Wire Communication Facilities
Selective Speed
Conforming to SRL Manual A24-3435
14.8 Cho,/Sec
IBM Line Adopte, (#4612)
for Limited Distance Line Adopter II.
(One per Line)
1030 Data Collection System
1031A Input
Station
Telephone Com pony Type 3002 600 bps
IBM Terminal Control Type II
Private Line Service or Privately
Not Required
Not Required
IBM Line Adopte, (#4612)
Owned Communication Facilities
60 Cho,/Sec
(One per Line)
Conforming to
SRL Manual A24-3435
Speed Extension Feature
for Limited Distance Line Adapter II.
1031A Input Station
Telephone Company Type 3002
Western Electric
Western Electric
IBM Terminal Control Type II
with Common Carrier Adapter
Private Line Service, Four-Wire
20201 20201
Data Set Line Adopter
12068 Full
Duplex.
(One per Line)
Speed Extension Feature
1070 Process Communications System
1071 Control Unit Modell
Telephone Company Type 3002
Western Electric
Western Electric
134.5 bps
IBM Terminal Coritrol Type 1
Private Line Service.
103F2 103F2
Selective Speed
Western Union Closs 0 (180 Baud)
Western Union Western Union
14.8 Cho,/Sec
Data Set Line Adapter
Channel
Data Set 1183A Data Set J183A
(One per Line)
1071 Control Unit
Model
1 Telephone Compony Type 3002
IBM Terminal Control Type I
with Line Adapter #4792
Private Line Service Of Privately
Not Required
Not Required
Selective Speed
Owned Communication Facilities
IBM Line Adopte, (#4612)
Conforming to SRLMonual A24-3435
(One per Line)
for Limited
Distance Line Adapter II.
1071 Control Unit Model 2
Telephone Company Type 3002
Western Electric
Western Electric
600 bps
IBM Terminal Control Type I
0'
Private Line Service, Four-Wire
20201 20201
Selective Speed
2740 Mod II with IBM Line Adopte, Full Duplex.
66.6 Char/Sec
Data Set Line Adopter
(One per Line)
#9121
Speed Extension Feature
1071 Control Unit Model 2
Telephone Company Type 3002
IBM Terminal Control Type I
with Line Adopter #4793 Private Line Service or Privately
Not Required Not Required
Selective Speed
0'
Owned,Communications Facilities
IBM Line Adapter (#4613)
2740 Mod II with Line Adapter
Conforming to SRL Manual A24-3435
(One per Line)
#4790 for Limited
Distance Line Adapter II.
Speed Extension Feature
TWX (Teletypewriter Exchange)
Models 33 and 35 TWX Terminals Common Carrier Switched
Western Electric
Western Electric 8-Level code
Telegraph Terminal Control
150 Baud TWX Networks
103AI 103AI at 110 bps
Type II
only
Data Set Line Adapter
(One per Line)
"Data Sets are those indicated or their equivalent. (See Chapter 3)
Figure 1-2. Attachable Terminals and Communication Facilities for Do'!'estic Use (Part 1 of 3)
Introduction 1-7

Terminal
Communication Facility
Terminal Data Set· Data Set· Speed Prerequistes
2740/2741 Communications Terminals
2740/2741 Communications Common Carrier ·Western Electric Western Electric
Terminal Switched Telephone
134.5 bps
IBM Terminal Control
Network 103A2 103A2
Type 1
Comma., Carrier
14.8 Char/Sec
Selective Speed Data
Switched TWX Network Western Electric Western Electric Set
line Adapter
(150
Baud)
103Al 103A1
(One per Line)
Western Union Western Union Western Union
Class D Chonnels
(180 Baud) 1183A 1183A
Telephone Company
A~ Appropriate Channel
Type 1006 Termination Provided by
Channels (150 Baud)
the Telephone Company
Telephone Company Type 3002 Western Electric Western Electric
Private line Service.
103F2 103F2
2740/2741 with Telephone Company Type 3002
134.5 bps
IBM Terminal Control
IBM line Adopter #4790 Private Line
Service or Privately Not Not Type I
Owned Communication Facilities
Required Required
14.8 Char/Sec
Se lective Speed
Conforming to SRL Manual A24-3435
I BM Line Adapter
for Limited Distance Line Adapter II. #4612
2740/2741 with Telephone Company Type 3002 I
BM Terminal Control
IBM line Adopter #4634 Private Line Service or Privately
Not Not Type I
Owned Communication Facilities
Required Required Se lective Speed
Conforming to SRL Manual A24-3435 I BM line Adapter
for limited Distance Une Adapter I. #4634 or #4638
Other Terminals
AT & T 8382/8383 Selective Telephone Company Type 1002 Not Not 45.5 bps Telegraph Terminal Control
Calling Terminal Channels (45
Baud) Required Required Type I
62.5 mo. 62.5 mo. Selective Speed
neutral neutral Te legraph line Adapter
d .c. loop,
d .c. loop, (One per
line)
tip negative I tip
negative,
Telephone Company Type 1002 ring positive ring positive 56.9 bps Telegraph Terminal Control
Channels (57 Baud) Type I
Selective Speed
Telegraph Line Adapter
(One per line)
Telephone Company Type 1005
74.2 bps Telegraph Terminal Control
Channe Is (75 Baud) Type I
Selective Speed
Telegraph line Adopter
(One per
line)
Western Union Plan 115A Western Union Not Not
45.5 bps Telegraph Adapter
Terminal Class A Required Required Type I #7860
Channels
62.5 mo.
62.5 mo.
neutral neutral
d
.c. loop,
d.c. loop,
tip negative, tip negative,
Western Union ring positive
dng positive 56.9 bps Telegraph Terminal Control
Closs B Type I
Channels
Selective Speed
(57 Baud) Telegraph
Line Adopter
(One per Line)
Western Union 74.2 bps Telegraph Terminal Control
Class C Type I
Channels
Selective Speed
(75 Baud) Telegraph Line Adopter
(One per Line)
*Data Sets are those indicated or their equivalent. (See Chapter 3)
Figure 1-2. Attachable Terminals, and Communication Facilities for Domestic Use (Part 2 of 3)
1-8

Terminal Communication
Facilities
Terminal Data Set Data Set Speed Prerequistes
Telephone Company Type 3002
Western Electric
Western Electric
2780 Private Line
Service with Type 202DI 202DI
1200
bps Synchronous
Clock Feature
1130
Cl Channel Conditioning.
2701 Western Electric Western Electric 2000 bps
2703
20lA3
20lA3
Telephone Company Type 3002
Private line Service with Type
C2 Conditioning.
Western Electric Western
Ele~tric
2400
bps
201 BI
201 BI
Switch Telephone Network Western Electrici Western Electric
1200
bps Synchronous Clock
Feoture,
202CI 202CI If Autocall feature is
installed, W.E. Automatic
Colling Unit 801AI or 801C2
(or equivalent) is required.
B01Al serves rotary pulse
dial-
ing; 801 C2 serves pushbutton
dialing. See common-carrier
representative for type
of dial-
ing facilities available.
Western Electric Western Electric
1200
bps Synchronous Clock
Feature,
202DI ·202DI
If Autocall feature is
installed, W.E. Automatic
Calling Unit 801 Al or 801 C2
(or equivalent) is required.
801 Al serves rotary pulse dial-
ing; 801 C2 serves pushbutton
dialing ..
See common-carrier
representative for type
of dial-
ing facilities available.
Western Electric Data
Aux i
Iiary Set B04A 1 or
equivalent.
Western Electric
Western Electric
2000 bps
If Autocall feature is
20lA3
20lA3
installed, W.E. Automatic
Calling Unit 801 AI or 80lC2
(or equivalent) is required.
80lAl serves rotary pulse dial-
ing; 801 C2 serves pushbutton
dialing.
See common-carrier
representative for type
of dial-
ing facilities available.
Western Electric Data
Auxiliary Set
804Al or
equivalent ..
Fi~ure 1-2. Attachable Terminals and Communication Facilities for Domestic Use (Part 3 of 3)
Introduction 1-9

Terminal Communication Facility Terminal Data Set Data Set Speed Prerequ isites
1050 and 1060 Data Communication Systems and 2740/2741 Terminals
1051 Control Unit Model 1 or 2
Common Carrier Leased Private IBM 3976
IBM 3976 134.5 bps IBM Terminal Control Type I
Line Telephone Service Selective Speed
1061 Control Unit Model I or 2 14.8 Char/Sec
Data Set Line Adapter
or (One per Line)
2740/2741 Terminal
1051 Control Unit
Madel
I or 2
Common Carrier Leased Private Line IBM Terminal Control Type I
2740/2741 Terminol Telephone
or Privately Owned Two
Not Requ ired
Not Required Selective Speed
or
Wire Communication Facilities
IBM Line Adapter #4612
1061 Control Unit Model
lor 2 Conforming to SRL Manual A24-3435
(One per Line)
with Line
Adapter #4790 for Limited Distance Line Adapler
Ii.
2740/2741 Communications Terminals
2740/2741 with
Common Carrier Leased Private Line
134.5 bps
IBM Terminal Control Type I
IBM Line Adapter # 4634
Telephone or Privately Owned Two Not Requ j red Not Required Selective Speed
Wire Communication Facilities 14.8 Char/Sec IBM Line Adapter # 4634
Conforming to SRL Manual A24-3435
for Limited Distance Line Adapter I.
2740/2741 with Common Corrier Leased Private Line I
BM Terminal Control Type I
IBM Line Adapter # 4790
Telephone or Privately Owned Two Not Required Not Required Selective Speed
Wire Communication Foci lities I
BM Line Adapter
Conforming to SRL Manual A24-3435
#4612
for Limited Distance Line Adapter II.
1070 Process Communication System
1071 Control Unit Model I
Common Carrier Leased Private IBM 3976 IBM 3976
134.5 bps IBM Terminal Control Type I
Line Telephone Service Selective Speed
14.8 Char/Sec
Data Set Line Adapter
(One per Line)
1071 Control Unit Madel 1 Common Carrier Leased Private Line
IBM Terminal Control Type I
with Line Adapter #4792 Telephone
or Privately Owned Two Not Required Not Required Selective
Speed
Wire Communication Facilities I
BM Line Adapter #4612
Conforming to
SRL Manual A24-3435
(One per Line)
for Limited Distance Line Adapter II.
1071 Control Unit Madel 2
Common Carrier Leased Four-Wire IBM 3977 Made I I IBM 3977 ModeI I
600.0 bps I
BM Terminal Control Type I
Private Line Telephone Service' Selective
Speed
66.6 Char/Sec
Data Set Line Adapter
(One per Line)
Speed Extension Feature
1071 Control Unit MadeI 2
Common Carrier Leased Private Line IBM Terminal Control Type I
with Line Adapter #4793 Telephone
or Privately Owned Two
Not Required
Not Required Selective Speed
Wire Communication Facilities IBM Line Adapter #4612
Conforming to SRL Manual A24-3~35
(One per Line)
for Limited Distance Line Adapter II. Speed Extension Feature
1030 Data Collection System
1031A Input Station
Common Carrier Leased Private Line 600 bps IBM Terminal Control Type II
Telephone or Privately Owned. Two
Not Requ ired Not Required IBM Line Adapter #4612
Wire Communication Facilities 60 Char/Sec
(One per Line)
Conforming
to SRL Manual A24-3435 Speed Extension Feature
for Limited Distance Line Adapter
II.
1031A Input Station
Common Carrier Leased Four-Wire IBM 3977 Mode I I
IBM 3977 Mode I I IBM Terminal Control Type II
with Common Carrier Adapter Private Line Telephone Service Dato
Set Line Adapter
#2068
(One per Line)
Speed Extension Feature
World Trade Teleprinters
W T Teleprinter
Common Carrier Private Line
IBM 3945 Mode I II 50 bps W T Telegraph Terminal Control
Telegraph Circuits (Double- Not Required Selective Speed
Current Telegraph Lines) Telegraph Line Adapter
(One per Line)
75 bps W T Telegraph Terminal Control
Selective Speed
Telegraph Line Adapter
(One per Line)
W T Teleprinter
Common Carrier Private Line
IBM 3945 Model 12
50 bps W T Telegraph Terminal Control
Telegraph Circuits (Single-
Not Requ ired Selective Speed
Current Telegraph Lines) Telegraph Line Adapter
(One per Line)
75 bps W T Telegraph Terminal Control
Selective Speed
Telegraph Line Adapter
(One per Line)
Figure 1-3. Attachable Terminals and Commlll1ication Facilities for World Trade Use (Part 1 of 2)
1-10

Terminal Communication
Facilities
Terminal Data Set
Dota Set Speed Prerequistes
2780 Leased
Voice Grade IBM 3977 ModeI 1 IBM 3977 Model 1 600/1 200 bps Synchronous
Clock Feature
1130
2701
IBM 3977 Model 2 IBM 3977 Model 2 Synchronous Clock Feature
2703
Up to 2400 bps
Figure 1-3. Attachable Terminals and Communication Facilities for World Trade Use (Part 2 of 2)
eight multiplexers can be attached to the channel, with
each multiplexer taking the place of one control unit.
Each communications line attached to the multi-
plexer is identified by a unique I/o address. The
addresses are shown in Figure 1-4. These addresses
are pluggable addresses and must be specified when
ordering the unit.
Because of the large amount of lines that can be
addressed in the 2703, the assignment of addresses
to particular start/stop lines is done in groups of
eight and must be done in a specific manner when·
configurating a system. For synchronous type lines,
address assignments are done in groups of four
lines.
The 2703 requires that the lowest address within
the 2703 begin at a specific address boundary. The
addresses are then assigned by group, consecutively
from the low-address boundary to the highest valid
address (or some group increment below this
address). The specific considerations necessary
when assigning 2703 addresses are:
1. A multiplexer channel can accommodate a
maximum of 256 individual addresses.
NOTE: Each address is associated with an individual non-shared
sub channel within the multiplexer channel.
Unit Group Address
Li ne Address
Any
One Combination
0,00
Addresses for Basic 15 Communication
from
Iines or less.
0000 1110
1111 Address for 16th line with 31 Line
1111
Extension Feature.
to
l> ~ombinations chosen must differ between
2702 groups.
Any One Combinatian
from
0000 0000 Addresses for 17th through
31 Line
~
with 31 Line Extension Feature.
1110
to 1111
0000 0000 Maximun 256 Addresses of which
1 1 only 176 can be used.
2703
1111 1111
Figure 1-4. Addressing Scheme
2. The specific address range available for
assignment is 0 to 255.
3. Anyone 2703 is limited to a maximum of 176
individual addresses (or lines).
4. The low-address boundary for address assign-
ment should be either 0 or a 16-unit increment
thereof (for example--16, 32, or 48. )
NOTE: A boundary of 48 should be used if convenient. This
starting number reserves sufficient positions to slow the
channel attachment of other devices with standard assigned
addresses. This also simplifies installation, since the low-
address boundary of 48 is pre-wired before shipping.
5. The high-address boundary must be an even
increment of either 8 (for start/stop) or 4
(for synchronous) from the low-address bound-
ary within the 2703.
6. The lowest address within the 2703 is always
assigned as the wrap address. The wrap
address is the address of the line used to read
data back to the channel from any line issued
the Wrap command. The wrap address and
its associated line can be used for normal
transmission at all times, except when the
2703 is being checked with a Wrap command.
A specific line base is assigned as the first line
base within the continuous span of addresses. Then
a line set of eight line adapters is added for this line
base. As many lines as desired (up to eight lines
for start/stop, or four lines for synchronous opera-
tion) are attached to this line set. Addresses are
assigned to all eight lines even if lines are not
attached. When the first line base is filled--or has
as many lines attached as desired--the addresses
are assigned to the second line base in the same
manner. Similarly, addresses are assigned to the
third line base if it is attached to the 2703.
If two 2703's are placed on the channel, the second
2703 may be placed with its lowest address in the
next increment of 16 not assigned to the first 2703.
Address assignment has no bearing on the priority
of any particular line. This is a function of the type
of line base and the number of lines.
The 2703 operates with non-shared subchannels
only and must have the highest priority on the
channel.
Introduction 1-11

Figure 2-1 shows all the operating commands used
by the IBM 2702 and 2703 Transmission Control
Units, the hexadecimal representation of the com-
mand byte sent over the IBM System/360 I/O Inter-
face, and the terminal controls that use the com-
mands. Some of the operating commands work with
the basic 2702/2703 and are independent of terminal
control type; some operating commands are not used
by all terminal controls; some operating commands
operate differently with different terminal controls.
2702 OPERATOR'S PANEL
The 2702 Operator's Panel is shown in Figures 2-2
and 2-3.
Operator Switches
Power On If in Local
This switch turns on 2702 dc power, provided the
Power Control switch is in the LOCAL or DRIVER
DEGATE position.
Power Off If in Local
This switch turns off 2702 dc power, provided the
Power Control switch is in the LOCAL or DRIVER
DEGATE position.
Meter On/Off (without Local/Remote Partitioning)
When this switch is placed in the OFF position, and
when the processor goes to a wait or halt state and
the 2702 is command-free, the 2702 goes off-line
and the 2702 usage meter stops running.
The Meter switch must be in the ON position for
the 2702 to operate on-line.
Local Partitioning
When the Local Partitioning switches or the Remote
Partitioning feature are installed, the Meter On/Off
switch is not present.
Interface A. When placed in the ACTIVE position
after a halt or wait state has been signaled, this
switch permits logical attachment to CPU A. When
placed in the INACTIVE position, this switch prevents
CHAPTER 2. OPERATIONS
the 2702 from becoming logically attached to CPU A.
If the 2702 is presently attached to CPU A, the 2702
becomes partitioned as soon as CPU A attains a halt
or wait state and channel A is unattached--for exam-
ple, the Release command has been issued to the
2702 and the 2702 is command-free.
Interface B. When placed in the ACTIVE position
after a halt or wait state has been signaled, this
switch permits logical attachment to CPU Bo When
placed in the INACTIVE position, this switch prevents
the 2702 from becoming logically attached to CPU B.
If the 2702 is presently attached to CPU B, the 2702
becomes partitioned as soon as CPU B attains a halt
or wait state and Channel B is unattached--e. g., the
Release command has been issued to the 2702 and the
2702 is command-free.
2712 Test Group 1 and 2
When the Group 1 or Group 2 switch is placed in the
LOCAL position, it permits a local high-speed wrap
operation to be performed to test the operation of the
2712 Adapter feature.
When placed in the REMOTE position, this switch
causes a high-speed wrap operation at the 2712 Multi-
plexer as well as the local wrap operation.
This switch is placed in the OPERATE position to
perform normal on-line telecommunication operations.
Operator Panel Indicators
Power-On
This indicator lights when 2702 dc power is on.
CE Test
This indicator lights when the CE Test switch at the
CE panel is depressed.
Thermal
This indicator lights when a thermal contact is open.
CB (Circuit Breaker)
This indicator lights when a 2702 power-supply cir-
cuit breaker is tripped.
Operations 2-1

X
*
**
00
01
02
03
04
05
06
09
OA
00
OE
13
17
IB
IE
IF
23
27
29
2F
04
F4
***
****
*****
2702/2703
IBM Terminal
Command Control
Type I
Test I/O
X
Write X
Reod X
No-Op
X
Sense X
Wrop X
Prepare X
Poll X
Inhibit X
Breok X
Search -
Sadzer *
Sadone *
Sadtwo *
Adprep -
Sadthree *
Set Mode -
Enoble X
Dial
****
Disable X
Release ***
Reserve
***
Uses Command.
Does not use Command.
2702 only--treated as No-Op in the 2703.
2703
only.
Two-Processor-Switch Feature only.
Auto-Coli Feature onl y.
Station Selection Feature only.
Figure 2-1. 2702/2703 Commands
2-2
IBM Terminal Telegraph Telegraph Synchronous
Control Type " Control
Type I ControI Type " Control **
X X X X
X X X X
X X X X
X X X X
X X X X
X X X X
X X X X
X --X
X X X -
-X X -
-X -*****
* * * *
* * * *
* * * *
---
*****
* * * *
---
**
X X X X
****
-
**** ****
X X X X
***
*** *** ***
*** ***
*** ***

POWER ON
IF IN
LOCAL II
PWR OFF
IF IN
LOCAL
Figure 2-2. 2702 Operator Panel
Usage Meter
ON
OFF
This meter indicates the elapsed on-line running
time of the 2702.
In-Sync
This indicator lights when synchronized data is being
recei ved satisfactorily.
Carrier-On
This indicator lights when the Carrier signal is
received from the 2712 Remote Multiplexer, indi-
cating that the 2712 Remote MUltiplexer is opera-
tional.
2702 CE PANEL
Figure 2-4 shows the CE Panel switches and indi-
cators.
CE Panel Switches
Machine Reset
The Machine Reset switch resets all 2702 registers
and LCW storage, except for the L1 and L2 check
bits.
Completing the reset initiated by this switch takes
1500 usec ± 25%; the 2702 signals Control Unit Busy
if initial selection is attempted during this time.
This switch is effective only when the 2702 is off-
line.
Display Line Ctl Word
This switch determines what information is captured
and displayed by the capture register; this information
is retrieved from the LCW of the communications
line selected by the Test-LCW Address switches.
With the Display Line Ctl Word switch in the A
position, the first 16 bits of the addressed LCW from
each delay line (L1 and L2) are captured and dis-
played.
With the Display Line Ctl Word switch in the B
position, the last 16 bits of the addressed LCW from
each delay line (L1 and L2) are captured and dis-
played.
With the Display Line Ctl Word switch in the S,
IO-LA position, the I/O register contents, the line-
adapter interface with the common controls, and the
S-line segment (if feature is used) are captured and
displayed.
Line Zero/Test- LCW Adr Switch
The Line Zero/Test-LCW Adr switch determines the
capture register display.
When this switch is in the LINE ZERO position,
the capture register will display, for line zero, the
fields selected by the Display Line Ctl Word switch.
When this switch is in the TEST-LCW ADR posi-
tion, the capture register will display the same infor-
mation for the line address entered in the Test-LCW
Address switches.
Test- LCW Address 1, 2, 4, 8, and 16
These switches are used to select a 2702 line to be
wrapped, displayed, or modified.
Operations 2-3

I THERMAL I
I PWR ON I I
PWR OFF I
c:J
[JCJ
IF IN
IF IN
TEST
LOCAL LOCAL
2712 TEST GROUP 1 2712
TEST GROUP 2
LOCAL
IN
CARR I ER
~,o~'
IN
CARRIER
SYNC ON
SYNC
ON
~oe,"",
00
OPERA TE
0 0
REMOTE
REMOTE
LOCAL PARTITIONING
I I
r-- INTERFACE
~
A B
I I I I I I I ACTIVE ACTIVE
0 0
INACTIVE INACTIVE
Figure 2-3, 2702 Operator Panel with TPS and 2712 Features
2-4