INSYS i-modul 336 LL User manual

Add-On Manual
INSYS Modem 336 LL
i-modul Modem 336 LL
(Modem for LeasedLine operation)
Aug-06

Copyright © August 06 INSYS MICROELECTRONICS GmbH
Any duplication of this manual is prohibited. All rights on this documentation and the
devices are with INSYS MICROELECTRONICS GmbH Regensburg.
Restrictions of guarantee
This handbook contains a concise description. The compilation of the text has been made
with the utmost care. Despite all efforts, there may be deviations compared with the ac-
tual functions. No guarantee can therefore be given for the accuracy of the contents. We
can neither take over a legal responsibility nor any liability for incorrect information and
their consequences. Suggestions for improvements and comments are gladly accepted.
Trademarks
The use of a trademark not shown below is not an indication that it is freely available for
use.
MNP is a registered trademark of Microcom Inc.
IBM PC, AT, XT are registered trademarks of International Business Machine Corporation.
INSYS ® is a registered trademark of INSYS MICROELECTRONICS GmbH.
Windows™ is a registered trademark of Microsoft Corporation.
Publisher:
INSYS MICROELECTRONICS GmbH
Waffnergasse 8
D-93047 Regensburg, Germany
Phone: [phone]
Fax: [phone]
e-mail: [email protected]
Internet: http://www.insys-tec.de
Subject to technical changes as well as correction.
Date: Aug-06
Item: 31-22-03.070 english
Version: 1.1
Language: EN

Inhalt
Aug-06 3
1BASICS........................................................................ 4
2MODEM CONFIGURATION ......................................... 6
2.1 CONFIGURATION MODE..............................................................6
2.2 TRANSMIT LEVEL........................................................................7
2.3 PING MODE AS CONNECTION SAFEGUARD ....................................7
2.4 STATUS TRANSMISSION OF THE DIGITAL INPUTS ..............................8
2.5 REMOTE CONFIGURATION............................................................8
3DIAGNOSIS AND TESTING OF THE PATH .................... 9
3.1 LINE OPTIMIZATION ...................................................................9
3.2 ERROR SOURCES ........................................................................9
3.3 DATA PROTOCOL DEPENDANT SETTINGS ........................................9
4TECHNICAL DATA .....................................................11
5FEATURES .................................................................12
6DECLARATION OF CONFORMITY ..............................13

Basics INSYS Modem 336 LL
i-modul Modem 336 LL
4Aug-06
1Basics
Leased line modems are used when a permanent connection between two data termi-
nals is required.
For these connections no regular switched line is used, but a dedicated (leased) line. This
can either be a line leased from Telekom, or just an unused pair e.g. on the premises.
Leased line modems establish a connection via such a two wire line immediately after
being switched on.
Leased lines are sometimes “serviced” which means they don’t represent a direct two
wire connection. The end terminals are supplied using a power supply unit.
The INSYS Modem 366 LL / i-modul 336 LL supports both variants. They operate polarity-
independent which means that a1 and b1 are interchangeable.
The two wire connection is the most used connection type.
Unserviced line
Serviced line
i-modul 336 LL /
INSYS Modem 336 LL
Originate
i-modul 336 LL /
INSYS Modem 336 LL
Answer
LA
LB
LA
LB
LA
LB
i-modul 336 LL /
INSYS Modem 336 LL
Originate
i-modul 336 LL /
INSYS Modem 336 LL
Answer
LA
LB

INSYS Modem 336 LL
i-modul Modem 336 LL
Basics
Aug-06 5
Note
For INSYS Modem 336 LL 4.1 and i-modul 336 LL 3.0:
Use AT&L<n> to switch between two wire operation (AT&L0) and
four wire operation (AT&L1).
During four wire operation, one pair each is needed for each transmission path (Origi-
nate →Answer and Answer →Originate). This will prevent problems with the terminat-
ing set (the part of the modem which separates received and sent data) for strongly mal-
adjusted lines.
Four wire line
Note
For leased line modems, it is required that one modem is operated
in originate mode and the other modem in answer mode.
For the connection start, the same protocols are used for switched line and leased line
operation.
The manufacturer will deliver completely pre-configured devices – Originate or Answer –
for two wire operation.
The difference lies in the factory settings for the S registry values (ATS11 und ATS7).
Originate: ATS11=3, ATS7=50
Answer: ATS11=1, ATS7=30
Note
For leased line modems, the same AT commands and S registries as
for switched line modems apply (see the Designer’s Guide i-modul
Modem or the User Manual INSYS Modem 336/56k) The only dif-
ference is the registry ATS11. For the switching line modem this
setting defines the DTC time setting, and for the LL modem it de-
fines the switching between Originate and Answer.
Basically, all connection protocols, error correction and compression methods which are
used for switched line operation, may also be used for the leased line mode. The AT
commands to set the desired protocol are identical to those of the switched line modem.
i-modul 336 LL /
INSYS Modem 336 LL
Answer
i-modul 336 LL /
INSYS Modem 336 LL
Originate
LB1
LB
LA
LA1
LB1
LB
LA
LA1

Modem Configuration INSYS Modem 336 LL
i-modul Modem 336 LL
6Aug-06
2Modem Configuration
2.1 Configuration Mode
The leased line modems have the same AT command set as the switched line versions. As
the modems attempt to establish a connection as soon as they are connected to a power
supply unit, they must first be returned to Configuration Mode.
The configuration mode is activated by pressing the RESET key (rail version) for a very
short time (<1s) or by briefly applying a RESET signal (module version, RESET is Low ac-
tive!).
The OH signal is inactivated (the modem “hangs up) and the modem can be configured
using AT commands.
After the configuration, the Connection State is activated, when:
-The operating voltage is switched off and back on,
-A Reset (>3s) is triggered, or
-The command “ATZ” is entered.
A built-in safety mechanism will furthermore automatically trigger a RESET, if no com-
mand is entered in configuration mode for more than 2 minutes. This mechanism will
protect the modem from unintentional interference pulses on the RESET line.
Prior to the configuration, the requested speed must be entered with the AT command
AT*S<n>&W, the data format with the AT command (AT*U<n>&W), and then saved. Dur-
ing the connection state, the INSYS Modems 336 LL can no longer be addressed via AT
commands.
The settings (baud rate, data format, error correction, data compression) must be the
same to guarantee trouble-free operation. For varied baud rates, handshaking must be
used to prevent the modem buffers from overflowing (the modem buffers can accom-
modate approximately 256 bytes in both the receive and send direction. If the individual
messages that are to be transmitted are shorter than the buffer length, and if a suffi-
cient delay time exists between the messages, even for varied baud rates handshaking
may be renounced).
Note
By default, handshake is deactivated (AT&K0) for the INSYS Modem
336 LL / i-modul Modem 336 LL 3.0. If handshake (RTS/CTS or
XON/XOFF) is required, it must be activated with the command
AT&K<n> (see manual).
Note
In contrast to the INSYS Modem 336 LL 4.0 (i-modul Modem 336), the
error correction for the INSYS Modem 336 LL 4.1 (i-modul Modem 336
LL 3.0) is set to V.42 by default (AT\N4). To enable operation with the
previous version (error correction by default MNP4 AT\N5), the INSYS
Modem 336 LL 4.1 (i-modul Modem 336 LL 3.0) must be configured

INSYS Modem 336 LL
i-modul Modem 336 LL
Modem Configuration
Aug-06 7
with AT\N5 at MNP4.
Note
All settings must be saved using AT&W as they are otherwise lost when
the connection is restarted!
2.2 Transmit Level
It may be required to adjust the transmit level of the modem to adapt it to the path.
The transmit level is set at –15dBm by the manufacturer and can be changed in the S
registry (ATS91). Transmit levels from –15 dBm (ATS91=15) to -6 dBm (ATS91=6) may
be set. The transmit level should be set to the same setting on both sides.
Attention!
In practice, a lower transmit level is often better, also for longer paths,
than a level that is too high.
If a transmit level is too high, malfunctions due to maladjustments and reflections may
prevent the signals of the remote terminal at the receiving modem to be interpreted cor-
rectly.
Note
If connection problems occur, one should always try to first reduce the
transmit level.
Gradually, set the S91 registry to a lower value.
2.3 PING Mode as Connection Safeguard
The leased line modems have an additional connection safeguard built in, which pre-
vents a modem connection to “hang up”.
This connection safeguard sends a short test message to the remote terminal in cyclical
intervals (every 20 seconds). If a modem does not get a proper test message from the
remote terminal on the receive side within 120 seconds it assumes that the connection is
no longer established and tries to re-establish the connection.
The used test message is initiated by a pre-defined character in the S registry
(ATS8=<n>). Factory setting: ATS8=3
According to the used protocol, it may be of advantage to change the initial character to
avoid unnecessary data transfer between the modems. All characters may be set with
the ASCII code 1..255.
ATS8=0 will completely deactivate the connection safeguard.
Note
The initial character must be set to the same character on both sides
to enable the modems to recognize the test messages of the remote
side. If different ping characters are set, the remote terminal will re-
ceive invalid characters and the connection will be interrupted in cycli-
cal intervals.

Modem Configuration INSYS Modem 336 LL
i-modul Modem 336 LL
8Aug-06
Note
PING mode will work with all buffered modes. It will not work with
direct mode (AT\N1).
2.4 Status Transmission of the Digital Inputs
If ping mode is activated (see Chapter 2.3), the status of the alarm inputs is automatically
transmitted to the switch outputs of the other modem, together with the ping mes-
sages.
A status change at one of the alarm inputs will automatically execute the sending of a
ping packet to the remote terminal. The maximum transmittable frequency is at ap-
proximately 0.5 Hz, i.e. the transmission may only be used for slowly changing status
lines.
2.5 Remote configuration
If connection safeguard is activated (see Chap. 1.3), this may result in problems during
the processing of AT commands in remote configuration mode.
For this reason, the connection safeguard should be deactivated at both modems prior to
the configuration.
Switching to command mode
<Pause>+++<Pause>
Deactivating the connection safeguard (local)
ATS8=0
Switching to remote configuration mode
<Pause>****<Pause>
Deactivating the connection safeguard (remote)
ATS8=0
Configuring the remote modem …
AT…
After the configuration, you can reactivate the connection safeguard at both modems
with ATS8=3&W (default).

INSYS Modem 336 LL
i-modul Modem 336 LL
Diagnosis and Testing of the Path
Aug-06 9
3Diagnosis and Testing of the Path
3.1 Line Optimization
To query the line quality and the received signal level a connection must be established
between the two modems (CONNECT).
Use the Escape sequence “+++” (with > 1 second pause before and after the sequence) to
switch to the online command mode.
Activate the level with the command AT%L. The displayed value in the scale – dBm is not
equivalent to the line level but the level within the data processor part of the modem.
The modem will be able to recognize a remote terminal up to the level value –40. The
optimum values will be around 20.
The command AT%Q queries the connection quality. Lower values indicate a better line
quality with a less significant error rate – for connections that have not been error-
corrected – and a higher data transfer rate for error-corrected connections.
The command ATO terminates the online command mode.
3.2 Error Sources
If the modems don’t establish a CONNECT at all, the following reasons could apply:
¾The two remote terminals were set to different connection protocols (V.xx,
to be set with AT+MS=<n>).
¾The two remote terminals are fixated on different error correction proto-
cols (None, MNP, V.42).
¾a1/b1 and a2/b2 have not been connected crosswise during four wire op-
eration.
¾The transmit level is too strong or too weak (check with a level gauge or ad-
just the S registry (ATS91) on both sides).
¾Strong interferences occur on the line (e.g. if the line has been running par-
allel to lines with high interference voltages).
¾The baud rate or the data format of the serial interface has been set incor-
rectly. Therefore the modem can not receive or send valid data.
3.3 Data Protocol Dependant Settings
Depending on the type of the transmitted data it may be necessary to change the basic
settings of the modem.
This concerns on the one hand the flow control (RTS/CTS, XON/XOFF, or no flow control)
and on the other hand the error correction/data compression.
The flow control is set with the command AT&K<n>, like for a switched line modem. Per
default the flow control is deactivated (AT&K0).
Error correction and data compression are activated in the factory settings.
If this leads to invalid delays for short data messages, the data compression
should be switched off with the command AT%C0+DS44=0 first.

Diagnosis and Testing of the Path INSYS Modem 336 LL
i-modul Modem 336 LL
10 Aug-06
If the transmission time is still too long, the error correction may be adjusted.
The following adjustment possibilities have an effect on the transient response
when performing an error correction.
¾Error correction type: V.42 or MNP4 (AT\N)
¾For MNP4: Block size (AT\A)
If necessary, the error correction may be completely switched off using the com-
mand AT\N0.
Without error correction, however, transfer errors on the line are possible, which
means that the data protocol should be designed in a fail-safe way.
Without error correction, data rates of up to 9,600 baud are possible for good
lines. Higher data rates are not recommended due to the many occurring errors.
For lower line quality, the error frequency will increase significantly according to
the baud rate, if no error correction is used.

INSYS Modem 336 LL
i-modul Modem 336 LL
Technical Data
Aug-06 11
4Technical Data
Transmitting power: -15 dBm to -6 dBm
(software settings)
Receiving sensitivity: Approx. –40dBm
Device terminator: Approx. 600 Ω
Bridgeable distance: Up to approx. 15 km possible
(line / interference dependent)
Connection standards: V.34+, V.34, V.32bis, V.32, V.22, V.22bis,
V.21, V.23, BELL-Norm 103, 212
Data compression according to MNP2-4,
V.42 LAPM, MNP 10, 10EC
Error correction according to V44, MNP5,
and V.42bis

Features INSYS Modem 336 LL
i-modul Modem 336 LL
12 Aug-06
5Features
¾Automatically establishes a connection immediately after being connected to a
power supply unit.
¾Automatically re-establishes a connection after an interruption of any kind has
occurred, as soon as the failure is remedied.
¾Connection with or without error correction possible.
¾Switch to initialization by briefly pressing the RESET key.
¾All switching operation settings may be used, but not all settings are suitable for
LL.
¾Setting of Originate/Answer via S registry (pre-configured by manufacturer).
¾Works with serviced and non-serviced lines.
¾Looping of the alarm input to the alarm output of the respective other module
(only for slow message lines < 0.5 Hz, only in ping mode).
¾Switchable from two wire to four wire
(only INSYS Modem 336 LL 4.1 and i-modul 336 LL 3.0)

INSYS Modem 336 LL
i-modul Modem 336 LL
Declaration of Conformity
Aug-06 13
6Declaration of Conformity