US Robotics COURIER HST User'smanual
[]11ilobotic:;
-------
HST™-
MODEM
-
9600
/
2400
/
1200
/
300
BPS, AUTO DIAL, AUTO ANSWER
MODEM
M610
-0 1
01
-00
WITH USR
HSr
M ERROR CONTROL
USER'S
MANUAL
USRobotics, Inc.
8100 North McCormick Blvd.
Skokie.
IL
60076
c
1986.
All
Rights
Re
se
rved
Courier
HST
is
a trademark
of
USRobotics. Inc.
Touch-Tone
and
Di
gital Data Service
(DDS)
are trademarks
of
American Telephone and Telegraph . MCI Mail is a service
mark
of
MCI
Communications.
Incorporated. Microcom Networkin g Protocol
(MNP)
is
a trademark
of
-"'1icrocom. Inc. Sprint
is
a trademark
of
General Telephone and
Electric.
Limited
Warranty
FCC
Registration
Connecting
to the
Telephone
Company
Radio
and
Television
Interference
For
Canadian
Modem
Users
How
to Use this Manual
COURIER HST
TABLE
OF CONTENTS
Vil
Vlll
VIII
IX
X
XI
PART
I.
INSTALLATION
AND
OPERATION
CHAPTER
I-Introduction
USR-HST
Trellis
Coded
Modulation
Asymmetric
Modulation
Enhanced
Error Control
Shorter
Response
Time
The
Courier
Product
Family
Courier
HST
Compatibility
CHAPTER
2-Set-Up
and
Testing
Package
Components
Operational
Requirements
Assembling
the
Modem
Testing
Analog
Loopback Self-Test
Additional Test Procedures
CHAPTER
3-0perations
at a
Glance
Data
Format
Error
Control
Dialing
HST-Compatible,
9600
bps
MNP-Compatible,
2400
or
1200 bps
Non-MNP
Compatible,
2400,
1200,
300
bps
Flow Control
Maximum
Throughput
High-Speed
Channel
Turnaround
Link Negotiation
Data
Rate Defaults
Nonvolatile
Memory
(NRAM)
Phone
Number
Storage
Dialing Stored
Numbers
1-1
1-1
1-1
1-1
1-1
1-1
1-3
2-1
2-1
2-1
2-2
2-5
2-6
2-7
3-1
3-1
3-1
3-1
3-1
3-1
3-2
3-2
3-2
3-2
3-2
3-3
3-3
3-3
3-3
iii
COURIER HST
IV
Busy Answer
Inactivity
Timer
CHAPTER
4-Interface
Controls
Terminology
Error Control
ARQ
Retry
Timer
Error Control Modes (&Mn)
With Auto Answer
Flow Control
Commands
Transmit Data Flow Control (&Hn)
Received Data Flow Control
Software Control (&In)
Hardware Control (&Rn)
Data Rate
Commands
Optional Fixed Rates
Terminal Rate Select (&Bn)
Link Rate Select (&Nn)
Rate-Select Guidelines
DSR Override (&Sn)
CHAPTER
5-Internal
Controls
Setting/Using Defaults
Writing Defaults to
NRAM
(&W)
Loading the Factory Defaults (&F)
Resetting to
NRAM
Defaults (Z)
Storing Telephone Numbers
(&Zn=
s)
Result Codes
Response Modes (Vn)
Result Code Sets
(Xn)
Result Codes Options Table
Options
Summary
Quiet Mode (Qn)
/ARQ
Result Codes (&An)
Local Echo
Command
Mode Local Echo (En)
Online Local Echo (Fn)
The Audio Monitor
Speaker Control (Mn)
Modem
Clock Usage (Kn)
Transmitter Enable/Disable (Cn)
Break Handling (&Yn)
The S-Registers
3-4
3-4
4-1
4-1
4-1
4-1
4-2
4-2
4-2
4-3
4-4
4-4
4-5
4-5
4-5
4-6
4-6
4-6
4-7
5-1
5-1
5-1
5-2
5-2
5-2
5-3
5-3
5-3
5-4
5-4
5-5
5-5
5-5
5-5
5-6
5-6
5-6
5-7
5-7
5-8
5-8
CHAPTER
6---Dialing and Answering
Basic Requirements
Transmission Rate
Error Control
Automatic Retrain
Placing Calls
Dial (D)
Dialing Type (T.
P)
Adaptive Dialing
Pause ( ,)
Dial and Return to
Command
Mode (;)
Dialing Letters
(")
Transferring Calls ( ')
Wait for a Second Dial Tone (W)
Wait for an Answer
((
i
t)
Reversing Originate/ Answer Frequencies
Canceling Dialing
Redialing
Reexecute the Last
Command
(A/)
Automated Redialing
Continuous Repeat ( > )
Continuous Reexecute (A> )
Exiting Repeat Mode
Dialing a Stored Number (DSn)
Pulse Dial Make/Break Ratio (&Pn)
Escape Code Operations (
+ + + )
ARQ
Mode Response
Normal Mode Responses
Returning Online
(0)
Hanging UP (Hn)
Automatic Answering
Suppressing Auto Answer
Points to Remember
U.S./CCITT
Answer Tone (Bn)
CHAPTER
7-Queries
and Help Screens
User
Inquiries (In)
S-Register Query (Sr?)
Sl7
S20
COURIER HST
6-1
6-1
6-1
6-1
6-2
6-2
6-2
6-2
6-3
6-3
6-4
6-5
6-5
6-5
6-6
6-6
6-6
6-7
6-7
6-7
6-7
6-7
6-7
6-8
6-8
6-8
6-9
6-9
6-9
6-10
6-10
6-10
6-10
6-11
7-1
7-1
7-3
7-3
7-3
V
COURIER HST
vi
Phone Number Query
(&Z11
'
1)
Help Screens
Basic Command Set
($)
Extended Command Set
(&$)
S-Rcgister Functions (
S$)
Dialing
(0$)
PART
II.
REFERENCE
APPENDIX
A-Error
/Flow Control Concepts
Overview
Throughput
MNP
Service Classes
Error Detection /Retransmission
Flow Control
Example
I-Transmit
Data
Example
2-Received
Data
APPENDIX
B-Summaries
and Tables
The RS-232C Interface, with Pin Definitions
Front End Indicators
DIP
Switch Summary
Default Settings
S-Register Summary
ASCII Chart
APPENDIX
C-Alphabetic
al Command Summary
APPENDIX
0-Problems
and Solutions
If
You Still Have Problems
APPENDIX
E-Additional
Operational Information
Using Both Voice and Data Communications
High Speed/Low Speed Protocol
Retrain Sequence
PBX,
Dedicated Line, and Leased Line Operations
Hewlett Packard Installations
APPENDIX
F-Technical
Specifications
GLOSSARY
INDEX
7-4
7-4
7-4
7-5
7-5
7-6
A-1
A-1
A-1
A-1
A-2
A-3
A-4
A-4
B-1
B-1
. I
B-2. I
B-3.
I
8-4.
I
B-5. I
B-6. I
C-1
D-1
0-3
E-1
E-1
. I
E-2.
I
E-3. l
E-4. 1
E-5. I
F-1
G-1
LIMITED
WARRANTY
COURIER HST
U.S. Robotics. Inc .. warrants to the original
consumer
or
other
end user purchaser that this product
is
free from
defects
in
materials
or
workmanship
for a period
of
two
years from the date
of
purchase. During the warranty period.
and upon
proof
of
purchase, the product will be repaired
or
replaced (with the same
or
similar model) at
our
option.
without charge for either parts
or
labor. This warranty shall
not apply
if
the product
is
modified, tampered with. mis-
used.
or
subjected to abnormal working conditions.
REPAIR
OR
REPLACEMENT
AS
PROVIDED UNDER
THIS
WARRANTY
IS
THE
EXCLUSIVE REMEDY
OF
THE
PURCHASER.
THIS
WARRANTY
IS
IN
LIEU
OF
ALL
OTHER
WARRANTIES. EXPRESS
OR
IM-
PLIED,
INCLUDING ANY
IMPLIED
WARRANTY
OF MERCHANT ABILITY
OR
FITNESS
FOR
A
PAR-
TICULAR
USE
OR
PURPOSE.
AND
U.S.
ROBOTICS
SHALL
IN
NO
EVENT
BE
LIABLE
TO
PURCHASER
FOR
INDIRECT
OR
CONSEQUENTIAL DAMAGES
OF
ANY
KIND
OR
CHARACTER.
Some states do not allow the exclusion
or
limitation
of
inci-
dental
or
consequential
damages
or
allow limitations on how
long an implied warranty lasts, so the above limitations
or
exclusion may not apply to you. This warranty gives you
specific legal rights, and you may also have
other
rights
which vary from state to state.
To
obtain service under this warranty. contact the U .S.
Robotics Technical Support Department at
800
/982-5151
(in Illinois, 312/
982-5151),
or
by mail at 8100 North
McCormick
Blvd.,
Skokie, Illinois. 60076. You will be
given a Return Materials Authorization
(RMA)
number
to
help us keep track
of
your warranty request.
Once
you have
received your
RMA
number,
take
or
mail the product, postage prepaid, to U.S. Robotics at the above address. Include
proof
of
the date
of
purchase. IMPORTANT: If you ship
your unit, pack it securely, be sure your
RMA
number
is
visible on the outside
of
the
package,
and ship it charges
prepaid and insured.
>-
Should you
encounter
problems in operating this device.
follow the instructions in Appendix D in Part lI
of
this man-
ual.
The
Appendix contains solutions to operating problems
as well as procedures to follow
if
there
is
an apparent
modem
malfunction.
vii
COURIER HST
FCC
REGISTRATION
viii
CONNECTING
TO THE
TELEPHONE
COMPANY
FCC68: CJE794- l l
323-DM
-E
RINGER
EQUIVALENCE:
048
FCCl5:
CJE
794FAST
It
is
not necessary to notify the teleph one
comp
any before
in
stalling the
modem
.
Howev
er. the telephone
co
mpany may
request the telephon e number(s) to which the Couri er
is
con-
nected and the FCC inform ation printed above.
If the telephone co
mp
any has any ques
ti
ons
or
raises prob-
lems, ask them to
ca
ll
the T
ec
hnical
Supp
o
rt
Department.
USRobotics. Inc .. 800/982-5151 (in Illinois. 312/982-5151).
If the mod em
is
malfunctioning.
it
may affect the telephon e
lines. In this
case.
dis
connect
the mod em until the source
of
the diffi culty
is
traced. Do not use the mo
dem
on party
or
co
in
telephone lines.
RADIO
AND
TELEVISION
INTERFERENCE
COURIER HST
This equipment generates and uses radio frequency energy
and if not installed and used properly.
in
strict accordance
with the
manufacturer's
instructions, may cause interference
to radio and television reception. The Courier
HST
has been
tested and found to comply with the limits for a Class B
computing device
in
accordance with the specifications
in
Subpart
J
of
Part
15
of
FCC
rules. which are designed to
provide reasonable protection against such interference in
a residential installation.
However, there
is
no guarantee that interference will not
occur
in
a particular installation.
If
this device does cause
interference to radio
or
television reception, which you can
determine by monitoring reception when the modem
is
on
and off, try to correct the problem with one
or
more
of
the
following measures.
Reorient the receiving antenna.
Relocate the
computer
with respect to the receiver.
Relocate the
computer
and/or the receiver so that they are
on separate branch circuits.
If necessary, consult your dealer
or
an experienced radio/
television technician for additional suggestions. You may
find the following booklet , prepared by the Federal
Commu-
nications
Commission,
helpful:
How to Identify and Resolve Radio-TV Interference
Problems
Stock No.
004-000-0345-4
U.S.
Government
Printing Office
Washington,
DC
20402
ix
COURIER HST
X
FOR
CANADIAN
MODEM
USERS
Th
e
Canadian
Department
of
Communication
s (DOC) label
identifies certifi ed equipment. This certificati on m
ea
ns that
the e
quipment
m
ee
ts
ce
rtain tel
eco
mmunications network
protective,
op
erational, and
saf
ety requirements.
Th
e depart-
ment
does
not guarantee the
equipment
will
op
erate to a
user's satisfaction.
B
efo
re installin g th is e
quipm
ent , ma
ke
sure you are permit-
ted to
connect
it
to the facilities of the local tel
eco
mmuni-
ca
ti
ons
compan
y. You must also install the equipm ent using
an acce ptable
method
of
connec
ti
on. In some case s, you
may also extend the c
ompan
y's
in
s
id
e wiring
fo
r s
in
g
le
line
individual ser v
ic
e by mean s
of
a ce rtified connec tor ass
em
-
bl
y (tele
phone
extension cord ). You should be a
war
e, how-
ev
er
. that compli ance with the above conditions may not
pr
event degradati on
of
service
in
some
situations.
Repairs to certified e
quipment
should be made by an author-
ized
Ca
nadian maintenance facility des ignated by the sup-
plier. An y repairs
or
alterations made by a use r to this
e
quipm
ent,
or
e
quipm
ent malfun c
ti
ons. may give the
tel
eco
mmunicati ons co
mpany
ca
use to request the us
er
to disconnect the equipment.
Fo
r your own protec
ti
on, make sure that the elec tric
al
ground connec
ti
ons of the
pow
er utility. telephone lines,
and internal metallic water pipe system,
if
present, are con-
nected together. This precaution may be particularly
impor
-
tant
in
rural areas.
CAU
TION:
Do not attempt to make such
co
nn
ec
ti
ons
yourself;
conta
ct the appropriate electric inspec
ti
on authority
or electrician.
Courier
HST Modern L
oa
d Numb er: 388
Th
e Load
Numb
er (LN) assigned to each terminal device
denotes the perce
nt
age
of
the total load to be co nnected to
the telephone l
oo
p used by the de
vi
ce. without overloading.
The termination on a loop may
co
nsist
of
an y combination
of devices. subject o
nl
y to the re
quir
ement that the total
of
the Load
Numb
ers
of
a
ll
the devices not exceed I 00 . An
alphabetic suffix is also specified
in
the Load N
umber
for
the appropriat e ringing type (A
or
8).
if
appli ca
bl
e.
For
example. LN
=
38 8 designates a Load
Numb
er
of
38 and
a 8 -type rin
ge
r.
HOW
TO USE
THIS
MANUAL
COURIER HST
This manual
is
divided into two parts. The first part
is
designed to aid you
in
getting your modem connected and
operating as quickly as possibl e. Part I
al
so includ es chap-
ters on
command
usage. Part
II
contains a number
of
informative appendixes that you may
or
may not nee d,
depending on your situation. plus a Glossary and Index.
Below
is
a brief description
of
the
manual's
contents. We
suggest you review at least Chapters
1-3
before operating
th
e modem.
• Chapter
I-Introduction
• Chapter
2-Assembling
and testing the modem
• Chapter
3-lmmediate
operations-essentials
• Chapter
4-Interface
controls
•
Chapter
5-Internal
controls
• Chapter
6-Calling,
answering and disconnecting
• Chapter
7-Inquiries
and Help screens
The appendixes in Pa
rt
II
cover
the following subjects:
• Background information on error and flow control
• Summaries and tables
• Problems, their causes, and solutions
• Additional operational information
• Technical specifications
Whenever a cross-reference
is
made to the same
or
a similar
subject,
you'
II
be directed to the appropriate section
of
the
manual with this arrowhead symbol,
~
xi
USR-HST
Trellis
Coded
Modulation
Asymmetric
Modulation
Enhanced
Error
Control
Shorter
Response
Time
THE COURIER
PRODUCT
FAMILY
MNP
Error
Control
at
2400/1200 BPS
COURIER HST
CHAPTER 1
INTRODUCTION
The USRobotics Courier HST modem represents powerful,
advanced electronic design that gives you optimal speed and
accuracy. USRobotics' High Speed Technology (USR-HST)
offers these advantages:
Trellis coded modulation
is
a convolutional coding technique
that makes data transmission less vulnerable to errors caused
by
phone network impairments.
It
can tolerate twice the telephone channel noise power as conventional modulation
(quadrature amplitude modulation,
or
QAM), so there are
fewer error-control retransmissions. Trellis coded modulation
is
also less susceptible to impulse-type noise.
At top speed, data flows
in
one direction at 9600 bits per
second and
at
300 bits per second
in
the other. The modems
automatically switch the high-speed channel on demand,
i.e.,
depending on which transmitter has the most data to
transmit. In practice, the modems seldom need to reverse
channels, since the asymmetric design reflects typical com-
munications sessions- brief messages typed at one end
of
the link, files sent from the other. The asymmetric approach
provides the most efficient and economical strategy for using
ordinary phone channels
at
high speeds.
The
HST
error control protocol uses sophisticated error
detection methods to ensure data integrity. Design efficiencies have reduced the overhead (extra control information) experienced with error control protocols at lower
speeds. On local and long-distance connections the result
is
accuracy. greater speed and higher
throughput-
approximately 1100 characters per second.
9600-bps modems are generally most efficient for file transfers. You'll find that the Courier HST also offers faster
response times during interactive sessions.
In addition to the Courier
HST's
new features, the modem
incorporates the same popular capabilities
of
other products
in
the Courier line:
The Courier HST implements the Microcom Networking
Protocol
(MNP), Service Classes
l,
2, and 3, at 2400 and
l 200 bits per second. This ensures compatibility with the
Courier 2400e and other MNP-compatible modems at
those speeds.
1-1
COURIER HST
Data Rate
Fall back
Inactivity
Timer
Call
Duration
Reporting
Ca
11
Progress
Detection
Modem
Settings
Display
HELP
Screens
Bottom
Panel
Reference
Repeat
Commands
Quote
Mode
Adaptive
Dialing
1-2
Automatic
Retraining
The
Courier
HST
automatically falls back to 2400. 1200.
and
300
bits
per
second . in both
Originate
and
Answer
Modes, to match a lower rate
of
a called
or
calling
modem.
You can optionally set local interface and link rates at
fixed speeds.
You
can
set the
modem
to automatically
hang
up after a
specified
number
of
minutes if there is no activity
on
the
phone
line.
The
modem
records the duration
of
your
calls in hours,
minutes,
and
seconds.
This
feature
enables
you to display
and print an audit
of
your
calling activities. You can option-
ally use the
modem
clock
as a real-time clock.
An optional set
of
result
codes
(screen messages) lets you
know
when
a line
is
busy, a person rather than a
modem
has
answered
the
phone,
there
is
no dial tone,
or
the distant
phone
is ringing.
On
command,
the
modem
displays its current settings, a
handy way to
check
your
transmission rate, S-registers and
other
operational controls.
You
can
also
displa
y screens that
summarize
the
command
sets. Dial
command
options,
and S-register functions.
Operational
summaries
and
other
information are printed
on
the
bottom
of
the
modem
case. A Dual In-Linc
Package
( DIP) switch guide
makes
it
easy to tailor the switch set-
tings to
your
requirements.
You can have the
modem
continuously repeat a
command
until you instruct
it
otherwise.
This
is
especially useful in
dialing services
whose
lines are often busy.
Set the
modem
to
Quote
Mode
if
you want
it
to dial
an alphabetic
"number,"
such as
800-"DIAL
USR"
(USRobotics'
Sales
Department).
You
can
set the
modem
to first try
Touch-Tone
dialing.
If
tone dialing
doesn
't work
on
the line. the
modem
automatic-
ally
switches
to the
slower
type,
pulse (rotary).
Retraining
(a
resynchronization with the remote
modem)
occurs
if
the
modem
detects line disturbances that might
affect
data
reliability. At
9600
bps the
connection
must be
with an
HST-compatible
modem.
Retraining also
occurs
at
COURIER
HST
COMPATIBILITY
COURIER HST
2400 bps if the
other
modem
is
Y.22bis-compatible.
(>
Ap-
pendix E-3 contains more information.)
The
Courier
HST
offers upgrading to
9600
bps while main-
taining compatibility with most installed 2400/
I
200/300 bps.
dial-up modems and existing software. Its compatibility
features include the following:
• Can be used with any
computer
or
terminal that
is
compatible with the RS-232C standard interface.
(>
For more information on the
RS-232C
interface.
see Appendix
8-
I . )
• Can be used with
any
computer
or
terminal that uses
ASCII,
the standard character code supported by most
equipment
manufacturers.
•
Connects
with any
modem
whose signal
scheme
is
compatible
with the following standards at the given
data
rate:
300
bps
1200 bps
2400
bps
9600
bps
Bell
!03
Bell 212A
V.22bis
USR-HST
• Uses the
HST
error
control protocol at
9600
bps
and.
optionally. the
MNP
error
control protocol, Service
Classes
I.
2
and 3 at
2400/1200
bps.
•
Is
fully FCC-certified for the uses described in this
manual.
1-3
PACKAGE
COMPONENTS
OPERATIONAL
REQUIREMENTS
COURIER HST
CHAPTER 2
SET-UP AND TESTING
Figure 2.
]-Courier
HST
The
box
containin
g
yo
ur
Courier
HST
contains
the following
it
ems in additi
on
to this
manu
al:
•
The
Courier
HST
mod
em
• An
RJ
I IC
phone
cord
• A
power
adapter
• A
Quick-R
efe
rence
card
,
in
the
manu
al
•
Your
warranty
card,
to be filled
out
and returned to
U
SRoboti
cs.
Inc.
The
Courier
HST
has
minimal
operational
requirements.
Be
sure to read th e
information
in the front
of
this
manual
about
radio
and
television interference
and
connecting
to the
phon
e
co
mpany.
In
addition.
you
should be
aware
of
the following:
•
Follow
the
operating
instructions in
Appendix
E-4
if
the
mod
em is to be used in
either
of
the following
types
of
in
stallation.
I
J
The
modem
will be installed in a k
ey
system
PBX
in
which
RJ
12
or
RJ
13
telephon e
ja
cks
are used
rather than the
RJ
I I jack.
2)
The
modem
will be attached to a use r-installed
phone line
or
a line l
ease
d from the
telephone
company.
Often
r
efe
rred to as
"dedi
ca
ted"
or
"private
...
this type of line is used for a
dir
ec
t.
2-1
COURIER HST
2-2
ASSEMBLING
THE
MODEM
continuous connection between two modems.
The connection
is
made without dialing.
•
If
the modem
is
installed in a Hewlett Packard system,
be sure to follow the instructions
in
Appendix E-5.
•
If
you're working with a computer rather than a ter-
minal, the computer must be in Terminal Mode.
If
you're not familiar with this requirement, check the
Glossary and refer to your communications software
documentation for instructions.
• You'll need an RS-232C cable to connect the modem
to your computer or terminal.
It should be a shielded
cable to ensure minimal interference with radio and
television reception. (~ For information on the RS232C interface, see Appendix B-1.)
The modem takes a DB-25P (25-pin plug) connector,
but computer equipment varies: check the serial port
at the rear
of
your machine. The port will be labeled
"Modem,"
"Communications,"
or
"EIA,"
or
with a
phone symbol. (Don't use the port marked
"Printer"
or
"Aux.")
If
the port
is
a plug, specify a DB-25S
(socket) connector to your dealer.
If the port
is
a
socket, specify a DB-25P (plug) connector. If your
machine has other than a 25-pin port, check your
documentation to see what type
of
RS-232C con-
nector
is
required.
I. Turn
off
the computer
or
terminal and its peripheral
devices.
2.
Examine the label on the bottom
of
the modem.
In
addition to the summaries and other information, the label
contains icons to aid
in
modem assembly. Then check
the interfaces at the back
of
the modem, shown in the
following photograph.
COURIER HST
Figure
2.2-lnterface
End, Courier HST
3.
Now
review the attached interfaces
in
Figure
2.3.
Figure
2.3-Connected
Courier HST
4. Check to make sure that the
power
switch
is
OFF; press
it
towards the zero in the
l/0
icon on the bottom label.
Then
plug the small end
of
the
power
supply cord into
the power jack at the back
of
the modem, and plug the
power
adapter into a standard 115-volts AC wall socket.
2-3
COURIER HST
2-4
Disconnect your present phone cable from the wall jack.
Plug one end
of
the phone cord that came with the
modem into the wall
jack,
and the other end into one
of
the phone jacks at the rear
of
the modem.
NOTE: Older telephone installations may not have the
appropriate modular wall jack and plug. Adapters and
RJ
11
C connectors are available from your telephone
company
or
computer dealer.
If
you want to keep your telephone connected for conven-
tional calls, plug its cord into the other jack at the rear
of
the modem. You can also use both your telephone and
modem
in
one call, although not at the same time.
>
Ap-
pendix E-1,
"Using
Both Voice and Data Communica-
tions,''
explains how to switch control
of
the phone line
between the modem and the phone.
5. Next, check the positions
of
the bank
of
Dual In-Line
Package (DIP) Switches located at the back
of
the
modem. These switches are set at the factory to the positions desired by most users, as shown in Figure 2.4.
QUAD 1 2
3
4 5 6
7
8 9
10
o;~
IL:::::,
~
1
1
~l..'.:...ll
~
I~~
I
~::'..L:.I
~~I~
1....'.:::'..l..~
I
~~I
~~I~
I
Figure
2.4-DIP
Switch Factory Settings
>
Use the guide on the bottom
of
the modem or refer to
the more detailed summary in Appendix
8-4
to determine
if
your situation requires a different setting.
If
you're
connecting the modem to a dedicated line or to a small
interoffice
or
PBX system, review Appendix E-4 for spe-
cial installation and operating instructions.
6. The final step
is
10
connect the modem to the com-
puter's
or terminal's serial port with the RS-232C cable
described earlier under
"Operational
Requirements."
Attach the appropriate connectors to the modem and to
the serial port.
N
OTE
: When you are using the modem, be sure not to
cover the vents on the top
of
the case.
The modem
is
now ready to be tested and operated.
TESTING
COURIER HST
To verify that your modem
is
working properly, follow
these steps:
I.
Tum
on your computer or terminal and clear the screen.
Then turn the Courier's power switch ON. These front
indicator LEDs will light
up:
HS
High speed: 9600 bits per second
CD Carrier Detect (if you haven't changed the
factory setting
of
DIP switch 6)
TR Data Terminal Ready (if you haven't changed
the factory setting
of
DIP switch
I)
MR Modem Ready/Power
RS
Request to Send, if your computer/terminal
supports RTS on the RS-232C interface
CS Clear to Send
2.
If
you're
using a personal computer, load your tele-
communications software and put your computer
in
Terminal Mode. This causes the computer to function as a
terminal rather than a processor: everything you type at
the keyboard goes directly to the modem.
If
necessary,
refer to your communications software documentation
for instructions.
3. Next, check to see
if
your machine and modem are communicating with each other by entering the command
to get the
modem's
"attention."
(Type either upper
or
lower case letters, not a combination. In this manual,
the Carriage Return
or
Enter key required to issue com-
mands
is
represented by the symbol
<er>.
Don't
type
the angle brackets.)
Type the following:
AT
<er>
If
everything
is
correct, the modem responds as follows:
OK
NOTE: The AT command
is
used alone to check the
modem/terminal interface. AT
is
also the mandatory
prefix for all other commands except A/ and
A>,
used to
repeat execution
of
the command in the command buffer,
and
+ + +, the escape code. These exceptions are
explained in Chapter 6.
2-5
COURIER HST
Analog
Loopbaek
Self-Test
2-6
4.
The
modem
is
shipped with DIP switch 4 UP. causing
the mod em to display (echo) your keyboard
commands.
If y
our
typed co
mm
and is not displa yed . y
our
l
oca
l ech o
is
OFF
. To turn the local ec ho
ON.
send the modem the
followin g
command.
ATE1
<
er
.->
If
double characters
appear
on the sc
re
en. both y
our
modem
and softw are are set to local echo
ON.
Either set
y
our
so
ft
ware to local
ech
o
OFF.
or
turn the mo
dem's
echo
OFF
with this
command
:
ATEO
<-
er
>
S.
If no
OK
a
ppear
s on y
our
screen. check out the
connec
-
tions at the interface
end
of the modem.
Then
ca
refully
review the previous instructions to see if you 've missed
s
omethin
g.
Another
way to verify that the
modem
is working properly
is to run this test. During Anal
og
Loopb
ack the modem
modulates and
demodulate
s dat a sent to it. and returns the
data to the screen. Follow these steps:
I. Because modulation at
9600
bps
is
asymmetric. the
self
-
test must be performed at 2
400
bps and below.
The
first
step
is
to
set your terminal or softw are to
2400
bps.
2.
The
mode
m·s
defa ult error
co
ntrol setting
is
&M4.
But
if the mo
dem
is
se t for error control (
&M4
or
&MS)
you wo
n't
be able to tell if there
is
a problem with the
modem
's transmitter
or
rec eiver, as
it
will retransmit any
errored data. For this reason, the following
command
sets
the modem to Normal Mode
(&M0)
before issuing the
command
for the test
(Sl6=5D).
The
t
es
t option caus
es
the
modem
to modulate and
demodul
ate its internal test pattern at the Origin ate (dial)
frequency and return the pattern to the screen. (Spaces
in
c
omm
ands arc unnec
essar
y, but are included
in
this man-
ual for r
ea
dability. ) Type:
AT
&MO
S16
=
5D
<
er
,
When
the
modem
enters Anal og Loopback Mode the
AL
indicator at the
fr
ont
of
the
modem
li
ghts. The mo
dem
g
oes
of
f ho
ok
(the equival ent
of
picking up a phone
Additional
Test
Procedures
COURIER HST
receiver), sends the message
CONNECT
2400 to the
screen. and then sends the test pattern.
3. Press any character key to terminate the test.
The
modem
goes back
on hook
(the equivalent
of
hanging up the
phone). and responds with the message NO CARRIER.
4.
Follow the same steps if you want to test the Answer
frequency, but substitute the Answer command (A) for
the Dial command (D).
If
you've
already set the modem
for Normal Mode, as
in
Step
2
above, you don't need to
type
&M0
again:
AT
&M0
S16
=
5A
<
er
>
5.
Reset your terminal
or
software to 9600 bps. Reset the
modem to its error control and Data Mode defaults with
this command:
AT
&M4
S16
= 0
<
er
>
You may want to take the time at this point to read the
following information on other test options, or skip
to
Chapter 3 for basic operational guidelines.
S-register
16
has five settings, explained in what follows.
0
I
2
Data Mode (no testing)
Analog Loopback
Dial Test
4 Test Pattern
5 Analog Loopback with Test Pattern
I.
To
perform analog loopback testing
of
the Originate or
Answer frequency without the test pattern, set the terminal or software to 2400 bps and issue either
of
the
following commands:
AT
&MO
S16
=
10
<
er
>
AT
&M0
S16
=
1A
<
er
>
The modem enters Analog Loopback Mode, goes
off
hook and displays the message
CONNECT
2400.
Type any message you wish at the keyboard.
It
is looped
through the modem and returned to the screen.
End the test by not typing anything for
at
least one sec-
ond and then typing three pluses. This
is
an escape code
2-7
COURIER HST
2-8
that forces the modem back to Command Mode
(don't
type the AT prefix or enter a Carriage Return):
+++
The modem returns the OK message.
To have the modem exit Analog Loopback Mode and
hang up the phone. first reset your transmission rate to
9600 bps. Then reset the modem to its error control and
Data Mode defaults with this command:
AT
&M4
S16=0
<er
2. The Dial Test is used to test the frequencies
of
Touch-
Tone values.
If
S16
is
set to 2 and a single Touch-Tone
is
dialed
(e.g.,
ATDT7
<er>),
the modem continues
to transmit that tone until another Carriage Return is
entered. This test
is
used
in
factory testing.
3. The Test Pattern alone
(ATS16=4
<er>)
is
used for
testing equipment and the phone line.
If
S
16
is
set to 4
and a Dial command issued, the modem transmits the test
pattern upon connection to the remote system. If set for
Auto Answer (DIP switch 5 UP). the modem transmits
the test pattern when
it
answers a call.
4. The preceding instructions test the modem at 2400 bps.
To test the modem
at
1200 or 300 bps, set your terminal or software to the lower speed and follow the same
procedures.
5.
It
might happen that you have issued either S
16
= I or 5
and the modem
is
in
Analog Loopback Mode, but you
haven't
yet sent a Dial or Answer command to initiate
testing.
If
the modem
is
also set for Auto Answer and a
call comes in, the Courier
HST
resets S
16
to zero and
answers the call.
NOTE: After any testing, be sure to reset S-register
16
for
normal Data Mode operations, with or without the default
error control setting (&M4):
ATS16=0
<er>
DATA FORMAT
ERROR
CONTROL
&MO
&M4
&M5
DIALING
HST-Compatible,
9600
bps
MNP-
Compatib/e,
2400
or
1200
bps
COURIER HST
CHAPTER 3
OPERATIONS
AT
A GLANCE
Here are some brief guidelines for immediate operation
of
the modem.
Ten-bit data units: check the table on page
6-1
or page
F-1
.
Both modems
must
be set to error control mode for error
detection and retransmission to occur.
Alwavs use error
control
for
9600-hps communications.
We use the term ARQ (automatic repeat request) for error
control. The three ARQ settings are as follows:
Normal Mode. No error control.
Normal/ARQ
Mode-Default.
The Courier attempts an ARQ
connection;
if
the signal isn't recognized. the modem contin-
ues
in
Normal Mode (&M0).
ARQ Mode. The Courier attempts an ARQ connection: if
the signal isn't recognized, the modem hangs up.
Use these settings/commands to call the following types
of
modems at the indicated speeds.
Terminal /software: 19.2k (preferable) or 9600 bps
Type:
AT
&H3
D
phone
number
<
er>
The command includes the setting for hardware/software
flow control ( &H3). See the flow control guidelines that
follow. 1f the modem isn't set for error control, include
&M4 or &MS
in
the command line.
Terminal/software: 19.2k, 9600, 2400 or 1200 bps
Type:
AT
&H3
D
phone
number
<
er
>
The command includes the setting for hardware/software
flow control (&H3). See the flow control guidelines
that follow.
3-1
COURIER HST
Non-MNP
Compatible,
2400, 1200
or
300
bps
FLOW
CONTROL
MAXIMUM
THROUGHPUT
HIGH-SPEED
CHANNEL
TURNAROUND
LINK
NEGOTIATION
3-2
See the flow control guidelines that follow.
Terminal/software: 2400. 1200
or
300 bps
Type:
AT
&M0 D phone
number
<er>
NOTE:
&M0
suppresses the MNP signals that may be misinterpreted by the remote system and prevent a successful
connection.
Hardware and/or software flow control can be used for
transmitted and received data. We recommend hardware
Transmit data flow control
(&HI)
since this setting
doesn't
affect the data stream. This is especially important
if
you're
transmitting binary data.
Use flow control
in
any
of
the following situations.
•
You're
using error control (9600/2400/1200 bps). Flow
control prevents buffer overflow
in
the event that line
disturbances cause frequent retransmissions.
• The rate at the local terminal interface is higher than
the link rate.
• The volume
of
data transfer
is
high.
Flow control commands are covered
in
Chapter 4.
Use these settings for both Originate and Answer Modes.
Terminal/software:
Modem:
19.2k bps
Fixed terminal interface rate
(&BI)
Variable link rate
(&N0)
Transmit Data flow control (
&H
1
preferred, &H2 or &H3)
As described
in
Chapter
I,
HST modems use asymmetric
modulation. The modems allocate the high-speed channel on
demand so that the modem with the greatest amount
of
data
in
its buffer transmits at 9600 bps. Turnaround
of
the chan-
nel is automatic and requires no user intervention.
When a Courier HST calls an HST-compatible modem and
both are operating at 9600 bps, the modems negotiate the
link connection
("shake
hands")
at 2400 bps and automatically resume operation at 9600 bps. The lower handshaking
rate maintains compatibility with the existing telephone network as well as existing hardware and software.
DATA
RATE
DEFAULTS
NONVOLATILE
MEMORY
(NRAM)
PHONE
NUMBER
STORAGE
DIALING
STORED
NUMBERS
COURIER HST
It's possible for
two
HST-compatible modems to connect
directly at
9600.
without 2400-bps handshaking, but
hoth
modems
must be set as follows:
Terminal/software:
Modem:
9600
or
19.2k bps
Fixed link rate
of
9600
bps (&N6)
Error control. either
&M4
or
&MS
Terminal interface:
&80,
detect rate from the AT
command.
then follow connection
rate.
Link interface:
&N0
, negotiate the highest possible
rate with the remote modem
in
both
Originate and
Answer
Modes.
The terminal interface and link rates may be set to fixed
rates using
&8
I and
&Nl-6,
respectively.
The
modem
is factory set
(DIP
switch
IO
OFF) to load the
settings stored
in
NRAM
on
power
up. Write
your
own
configuration defaults to
NRAM
with the
&
W
command.
To
review the
NRAM
settings, refer to Appendix
8-3
or
type:
ATl5
<
er
'>
Use
&Zn
=
s
to store four frequently
ca
lled phone numbers
in
NRAM
(nonvolatile memory);
11
=
positions
0
through
3,
s
=
number-string.
The
string may contain a
maximum
of
36
characters and any Dial
command
options.
Example:
AT&Z
=
9,, 1 312 5551234
<
er
>
(Store at position 0)
Example :
AT&Z1
=
5551234
<
er
>
(Store at position I)
To
dial, issue the
DS11
command
, where
II
indicates the
position
of
the
number
in
NRAM.
Example:
ATDS
1
<
er>
(Dial
number
at position
1)
The first
command
in the following sequence stores the
phone
number
and access code for a long distance service.
The second
command
dials the stored
number
/access code
and continues dialing the long distance phone number.
AT&Z2
=
5551234,,9876
,,
<
er
>
ATDS2
D1
312
5556789
<
er
>
3-3
COURIER HST
BUSY
ANSWER
3-4
INACTIVITY
TIMER
Use A> instead
of
Al
and the modem redials up to
IO
tries
instead
of
once. Neither A> nor
Al
takes the
AT
prefix
or
a Carriage Return.
Add the Repeat Mode
command(
> ) to the Dial
command
string and the modem automatically redials up to
10
tries:
AT>
D5551234
<er
>
ATD5551234
> <
er
>
You may include the Repeat command when you store a
phone number-string
in
NRAM:
AT&Z2
=
5551234
> <
er
>
Set the inactivity timer (S-Register 19)
if
you suspect that
a connection may be inadvertently left open without data
transfer.
TERMINOLOGY
ERROR
CONTROL
ARO
Retry
Timer
COURIER HST
CHAPTER 4
INTERFACE CONTROLS
Use the
comm
ands explained
in
this chapter to select the
mode
m's
operating characteris
ti
cs at the terminal and link
interfaces. Th e
co
mmands apply to error and
fl
ow control,
and to the speed-select options at both interfaces.
)lo-
For
background informa
ti
on on
th
ese f
ea
ture s, see App endix A.
NOTE:
When
yo u change a defa ult settin g during a ses-
si
on. the mod em retains that setting until you do o
ne
of
th
e fo llowing:
• Select a n
ew
setting.
• Issue the Z
co
mmand to rel
oa
d the
NR
AM
defaults
or
the &F
co
mmand to l
oa
d the factor y settings.
•
Tum
the modem off.
For simplicit y. references to a
terminal
in
this chapter mean
bo
th
conventional terminals and
mi
crocomputers.
A
RQ
(a
ut
omatic rep
ea
t request. i.e. retransmission) is the term
used by USR obo
ti
cs in error
co
nt
rol commands and re-
sponse codes.
In
summ a
ri
es. the terminal is referred to as DTE, for Data
Terminal Equipment. while the mo
dem
is
referred to as
D
C£
, for Data
Co
mmunications Equipment. DTE/
DCE
indi-
cates the terminal/mo
dem
interface.
DCE/DC
E indicates the
link (modem -to-m odem) interface. (For
mor
e
in
fo
rmation
see
th
e Flow
Co
ntrol section
in
Appendix A.)
While error
co
nt
rol is option al.
it
should always be selected
fo
r
96
00
bps sessions.
The
USR-HST proto
co
l
is
used at
9600 bps. The
MNP
protocol is used at 2400 and 1200 bp s.
Bo
th
protocols use cyclic redundancy checking
fo
r error
detection. and an a
ut
omatic rep
ea
t request (ARQ ) for
retransmission
of
errored data frames.
It
may happen
th
at a retransmission request
fo
r
th
e same
frame occurs repeatedly. Ordinarily this is due to a serious
disturbance
in
the phone conn
ec
ti
on. The retry maximum is
12.
af
ter w
hi
ch the mo
dem
s a
ut
omatically hang up ins
te
ad
of
running up was t
ef
ul
phone charges.
If
the Co urier han gs
up and you
don't
know why, query register S20 with
this command:
ATS20?
<,
er -,
4-1
Loading...