AGM DLM User manual

Dial-Up / Leased-Line Modem
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+
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CD
CTS
RTS
DTR
DSR
RI
PHONE
LINE
RX TX
DLM
AGM Electronics, Inc – Dial-Up / Leased-Line Modem, Series ( ) 5019-1
Manual Rev A
User Manual

Dial-Up / Leased-Line Modem

Dialup / Leased Line Modem
CONTENTS
INTRODUCTION........................................................................................................................................................... 1
Overview..................................................................................................................................................................2
Theory of Operation and Construction ..............................................................................................................2
General Specifications..........................................................................................................................................4
HARDWARE INSTALLATION..................................................................................................................................... 5
TELEPHONE CONNECTION ................................................................................................................................... 5
LEASED-LINE CONNECTION ................................................................................................................................. 5
POWER CONNECTION ............................................................................................................................................ 5
CONNECTING TO A PERSONAL COMPUTER..................................................................................................... 6
CONNECTING TO AGM DATA HANDLER (DH) RS232.......................................................................................7
CONNECTING TO AGM INTEGRATED CONTROL STATION (ICS) .................................................................. 7
CONNECTING TO AGM UNIVERSAL WEB STATION (UWS) ............................................................................ 8
CONNECTING TO A 3RD PARTY PLC.....................................................................................................................8
GETTING STARTED .................................................................................................................................................... 9
SETTING DLM FOR DIAL-UP OPERATION........................................................................................................... 9
SETTING DLM FOR LEASED-LINE OPERATION...............................................................................................11
CONFIGURATION......................................................................................................................................................13
ENTERING COMMAND MODE..............................................................................................................................13
COMMON COMMANDS..........................................................................................................................................14
Answer (A).............................................................................................................................................................14
Dial (D)....................................................................................................................................................................14
Echo Character (E)...............................................................................................................................................14
Hang Up (H0).........................................................................................................................................................14
Monitor Speaker (M) ............................................................................................................................................14
Result Codes Enable (Q).....................................................................................................................................14
Result Codes Format (V).....................................................................................................................................14
Carrier Detect (&C)...............................................................................................................................................14
Data Terminal Ready DTR Control (&D)...........................................................................................................15
Load Factory Settings (&F0) ..............................................................................................................................15
Flow Control (&K).................................................................................................................................................15
Leased-Line (&L)..................................................................................................................................................15
NOTE: For Leased-Line operation one DLM must be set for Originate and the other must be set for
Answer. 15
DSR Control (&S) .................................................................................................................................................15
Display Configuration Settings (&V).................................................................................................................15
Save Changes (&W0)...........................................................................................................................................15
AT Command Control (%DC).............................................................................................................................15
Inactivity Timer (\T) ..............................................................................................................................................16
Data Format ($EB) and (#P)................................................................................................................................16
Serial Port Baud Rate ($SB) ...............................................................................................................................16
MODULATION COMMANDS..................................................................................................................................17
Modulation Selection (+MS=).............................................................................................................................17
Display Modulation Selection (+MS?)...............................................................................................................17
Error Control (&Q)................................................................................................................................................17
S REGISTERS..........................................................................................................................................................18

Dialup / Leased Line Modem
TECHNICAL SUPPORT.............................................................................................................................................19
DIAGNOSTICS AND TROUBLE SHOOTING..........................................................................................................20
INDICATOR LIGHTS................................................................................................................................................20
TROUBLESHOOTING HINTS.................................................................................................................................20
Loss of Connection / Failure to Connect..........................................................................................................20
Failure to Disconnect on Dial-Up Connections...............................................................................................23
Failure to Disconnect on Loss of Carrier .........................................................................................................24
DLM Tries to Connect Immediately on a Dial-Up Phone Line.......................................................................24
APPENDIX A................................................................................................................................................................25
WIRING AND SIMPLIFIED DIAGRAM...................................................................................................................25

Introduction
Dialup / Leased Line Modem
1
Introduction
Thank you for purchasing the AGM Dial-Up / Leased-Line Modem (DLM). The AGM Dial-Up /
Leased-Line Modem provide a variety of cost effective data communication possibilities. This
manual covers installation and setup of the more commonly used configurations.
Pin Description
1 Power (+)
2 Power (-)
Monitoring Speaker
Phone Line Connection
(RJ11)
Screw Terminal Connections
RS232 Connector (Female)
Carrier Detect Indicator
CTS Indicator
RTS Indicator
DTR Indicator
DSR Indicator
Ring Indicator

Introduction
Dialup / Leased Line Modem 2
Overview
The AGM AUX/DIN 5019-1 DLM is a low cost V.92 modem which supports Leased-Line as
well as Dial-Up connections. The DLM complies with FCC and other international regulations
for connection to public telephone systems. The DLM may also be used over a dry metallic
pair of lines.
The DLM is for use with RS232 system.
The standard DLM communicates using the V.92 modem standard and is backwards
compatible with earlier modem standards. It is configured using the AT command set
common with most commercial Dial-Up modems found in desktop and laptop computers.
The default configuration of the DLM will automatically detect the correct data
communications rate however the DLM can be set to use a specific rate such as 9600 bps if
required. Fixing the communications data rate can eliminate some connection problems
when communication conditions are not optimal.
Theory of Operation and Construction
The heart of the DLM is an industrial hardened V.92 modem that integrates most of the
common error correcting and data compression algorithms found in many commercial
modems such as those found in your desktop or laptop computer. Unlike the modem found
in your desktop, the DLM also incorporates a Leased-Line feature which allows the DLM to
be used over a Leased-Line from the phone company or via a dry metallic pair of wires.
The DLM may be used with any protocol that uses 7 or 8 bit asynchronous data. This
includes but is not limited to: ASCII Modbus, RTU Modbus, DF1, or DNP3. You do not need
to own AGM Electronics Inc. equipment to use the DLM.
The DLM is configured by using a computer and any terminal emulation software such as
AGM’s SCADA, AGM’s Communicator or Hyper Terminal which is packaged with Microsoft
Windows. The DLM may be configured in the field using a laptop computer and RS232
cable.
When used for a Dial-Up connection the DLM acts like any external Dial-Up modem that you
may have connected to your computer. When the DLM receives a dial command “EG
ATD123-4567” the DLM will go off hook, check for a dial tone and then dial the number.
When the receiving DLM or modem detects a ring on the phone line, the modem answers
then emits a tone. When the originating DLM detects the tone from the answering modem
the two modems will then attempt to negotiate a connection rate. Once the data rate has
been negotiated the CD light will be turned on and if enabled a connect message will be sent
to each of the connected devices.
When used in the Dial-Up configuration the DLM is compatible with most other commercial
modems that adhere to one of the supported standards.

Introduction
Dialup / Leased Line Modem
3
When used with a Leased-Line connection one DLM must be set up to “originate” and the
other to “answer”. After approximately 30 seconds after power up one DLM will start emitting
a tone and the other DLM will listen for the tone. Once the tone is detected the two DLM’s will
negotiate a connection as in a Dial-Up connection.
NOTE: In Leased-Line mode the AGM Electronics DLM is only compatible with another
AGM Electronics DLM. Connection to other Leased-Line modems is not
supported. Also, multi-drop connections are not supported.
When you order your DLM indicate how you would like to have the DLM configured. AGM
Electronics Inc. will configure your DLM at the factory free of charge.
The hermetically sealed assembly minimizes installation costs.

Introduction
Dialup / Leased Line Modem 4
General Specifications
Connections – 1 RS232C; Power; RJ-11 Telephone Company
Baud Rate – 0 – 300; 1200; 2400; 4800; 7200; 9600, 12,000; 14,400; 19,200; 21,600;
24,000; 26,400; 28,800; 31,200; 33,600 bps
Data Compatibility – V.92; V.34 enhanced; V.34; V.32bis; V.32; V.22bis; V.22; Bell 212A and
103/113; V.21 and V.23
Data Compression – ITU-T V.44; V.42.bis; MNP 5
Error Correction – V.42
Status Indicators – 8
Operating Temperature Range, -20/80 deg C
Adjustments – Operator configurable locally from a PC
Power – 11/30 VDC +/- 10%, nominal 2.5 Watts
Physical – 3 X 1.4 X 3.5 (DIN), 3 X 1.4 X 2.7 (AUX)
Safety Certifications – UL60950; cUL60950; EN60950; IEC6090; ACA TS001 / AS 3260
EMC Certifications – FCC Part 15; Canadian EMC; EN 55022; EN 55024; GB4943; GB9254
Registration No – AU7USA-25814-M5-E
Ringer Equivalence – 0.3B

Hardware Installation
Dialup / Leased Line Modem
5
Hardware Installation
The DLM is available pre-configured to your application. When pre-configured, the DLM is
ready for use and you only need to connect your equipment. If not pre-configured or if you
need to modify the configuration you will need to connect the DLM to a computer containing a
RS232 serial port and terminal emulation program. Hyper Terminal is available on any
Microsoft Windows 95/98/NT/2000/XP system.
Telephone Connection
The telephone line connector on the DLM is a standard RJ-11 telephone jack. Use a
standard telephone modular cable to connect between the DLM and the RJ-11 telephone
jack supplied by the telephone company.
NOTE: The DLM should only be plugged into a standard telephone line or dry metallic pair
of lines. Some digital telephone and other systems may also use a RJ-11 jack for
connecting their digital phones. The DLM is not compatible with these types of
systems and plugging the DLM into one of these systems may result in damage to
the DLM and phone system.
Leased-Line Connection
The DLM uses the same RJ-11 jack for connecting Leased-Lines as well as standard Dial-Up
lines. The DLM will operate with a dry metallic pair of lines. Connect the dry pair to a
modular RJ-11 plug or jack then plug the dry pair into the DLM’s RJ-11 jack. Use the two
center connections of the RJ-11. The phone lines used by the DLM are not polarized.
Power Connection
The DLM will operate from either a 12 VDC or 24 VDC supply system that is capable of
supplying 300 mA. Connect the positive lead of your power supply to pin 1 of the connector
and the negative lead to pin 2 of the connector. Should you ever be required to remove the
DLM you may un-plug the connector by lifting straight up from the body of the DLM. You do
not need to remove the power wires once installed.
When power is applied the “DSR” light should turn on immediately followed by the “CTS” no
more than one second later. Until you connect up your computer, PLC or other RS232
device these are the only two lights that will be on.

Hardware Installation
Dialup / Leased Line Modem 6
Connecting to a Personal Computer
Use the following procedure to connect the DLM to your computer for either configuration
changes or use.
You will need a “straight-through” cable to connect to the DLM. This cable should have a 9 or
25 pin female connector on one end to match the connector on you computer and a 9 pin
male connector on the other end to mate with the DLM. Cables, adapters and gender
changers designed for connecting a computer to a modem are available through many
computer, electronic or office supply stores.
The DLM also supports RS232 using only 3 wires, Transmit, Receive and Ground. Typically
3 wire RS232 is only used with custom cables to reduce the wiring cost. If using 3 wire
RS232 you will need to disable DTR detection and hardware handshaking by configuring the
DLM with “AT&K0&D0&W0” command. These changes are done via configuration
commands entered while connected to the DLM. You may need to initially connect to the
DLM using a standard RS232 cable or order your DLM preconfigured for 3 wire operation.
NOTE: While using the DLM with only 3 RS232 wires the “RTS” and “DTR” lights will
remain off. You will also not be able to use hardware handshaking or be able
to hang up the phone line by toggling the “DTR” line. Make sure any
connected hardware does not require the use of these lines.
1. Plug one end of the RS232 cable into an available RS232 communications port your
PC. This port is normally a 9 pin male D connector; however it may also be a 25 pin D
connector in some cases. Consult with your PC documentation for the location of this
connector.
2. Plug the other end of the RS232 cable from your PC into the 9 pin female D
connectors on the top of the DLM.
3. Start Hyper Terminal or other terminal emulator program. Select direct connect to the
serial port connected to the DLM. Unless configured for another baud rate or data
format, select 9600 bps (baud), 8 data bits, no parity, and 1 stop bit. If connecting for
configuration, turn off all handshaking.
If properly connected and not using a 3 wire connection the “CTS”, “RTS”, “DTR” and
“DSR” lights should be on. If not on check your cable connections and RS232 port on
your computer. If using 3 wire RS232 the “RTS” or “DTR” lights will be off. You can
only test a 3 wire RS232 connection by observing the “TX” light on the DLM and typing
keys on your keyboard while connected to the DLM.
4. Cycle the power and wait for the “CTS” and “DSR” lights to turn on. Then within 10
seconds type “ATi” followed by a carriage return (Enter key) in your terminal emulator
program. If properly connected you should see a text response on your screen. The
“TX” light should flash when you are typing. The “RX” light may flash when you type a
key or just after you press the carriage return key (Enter key).

Hardware Installation
Dialup / Leased Line Modem
7
NOTE: In some cases you can simply check the connection by entering just the
“AT” command and watching for “AT” to be echoed followed by “OK”. The
echoing of command characters as well as the response codes can be
disabled so simply entering “AT” will not work. Also when used in the
Leased-Line mode the DLM will only accept commands within the first 10
seconds after power up. Following the above procedure of cycling the
power then entering “ATi” will work in all cases.
Connecting to AGM Data Handler (DH) RS232
To connect a DLM to a RS232 Data Handler you will need a 9 pin female to 9 pin male null-
modem cable.
1. Plug one end of the RS232 cable into the 9 pin male connector on the Data Handler.
2. Plug the other end of the RS232 cable into the 9 pin female D connector on top of the
DLM.
3. Power up both the Data Handler and DLM. If properly connected the “DTR”, “DSR”,
“CTS” and “RTS” lights should be on. If “RTS” light is off the Data Handler may be
configured for half-duplex operation you may either turn off the half-duplex in the Data
Handler or disable the hardware handshaking in the DLM. Hardware handshaking
may be disabled by connecting the DLM to a computer then entering “AT&K0&W0”.
Connecting to AGM Integrated Control Station (ICS)
To connect a DLM to an ICS you will need a 9 pin male to 25 pin female straight through
cable.
1. Plug the 25 pin end of the cable of the RS232 cable into the 25 pin D connector on the
back of the ICS.
2. Plug the other end of the RS232 cable into the 9 pin female D connector on top of the
DLM.
3. Power up both the ICS and DLM. If properly configured the “DTR”, “DSR”, “CTS”, and
“RTS” lights should be on. If these lights are not on check your cable connections.

Hardware Installation
Dialup / Leased Line Modem 8
Connecting to AGM Universal Web Station (UWS)
To connect a DLM to a UWS Data Handler you will need a 9 pin female to 9 pin male straight
through cable.
1. Plug one end of the RS232 cable into one of the 9 pin male connectors on the UWS.
Select either “A” or “B” depending on which port will be used with the DLM.
2. Plug the other end of the RS232 cable into the 9 pin female D connector on top of the
DLM.
3. Power up both the UWS and DLM. If properly configured the “DTR”, “DSR”, “CTS”,
and “RTS” lights should be on. If these lights are not on check your cable
connections.
Connecting to a 3rd Party PLC
The DLM supports any PLC that uses a protocol based on 7 or 8 data bit asynchronous serial
communications. This includes ASCII Modbus, RTU Modbus, Allen-Bradley DF1 Half Duplex
and DNP3 protocols. You must have the appropriate RS232 interface installed. Consult with
your PLC manufacture on the RS232 interface to use.
You will need a cable to connect from your PLC to a Modem. If a cable of this type is not
available you will need a Null-Modem adapter and possibly a gender changer to connect your
PLC to the DLM. Null-Modem adapters and gender changers are typically available through
many computer, electronic or office supply stores.
1. Plug one end of the RS232 cable into your PLC. See your PLC documentation for
making this connection.
2. Plug the other end of the RS232 cable from the PLC into the 9 pin female D connector
on the top of the DLM.
3. Power up both the DLM and PLC. If properly configured the “DTR”, “DSR”, “CTS”,
and “RTS” lights should be on.
Some PLC’s may not provide full hardware handshaking. These PLC’s may still be
used with the DLM however you will need to disable the hardware handshaking and
DTR control in the DLM. Hardware handshaking may be disabled by connecting the
DLM to a computer then entering “AT&K0&W0”. DTR control may be disabled by
connecting to a computer and entering “AT&D0&W0”.

Getting Started
Dialup / Leased Line Modem
9
Getting Started
The DLM may be preconfigured at the factory. In this case your DLM should be ready to use
after you have made all hardware connections. If not preconfigured the following two
sections will provide instruction on configuring your DLM. See the Configuration Commands
section for details on some of the available DLM configuration commands.
To configure your DLM you will need to connect to a computer running Hyper Terminal or
other terminal emulator program. See Connecting to Personal Computer section above for
details on how to connect to your computer.
Setting DLM for Dial-Up Operation
The basic configuration for Dial-Up operation is the same whether the DLM will be dialing out
or answering. Each of the following commands will be entered then followed with a carriage
return (Enter Key). After entering each command wait for the “OK” response.
1. Turn on the DLM and as soon as the “DSR” and “CTS” lights turn on enter:
AT%DC0
NOTE 1: You may not get a response from this command. Some configurations
disable the response to commands as well as the echoing of characters.
NOTE 2: It is possible to set up the DLM to ignore any commands. To break out of
this mode the “%DC0” command must be sent within the first 10 seconds
after power up.
2. Reset the DLM to its factory defaults by entering: AT&F0
NOTE 1: You will get an “OK” response from this command.
NOTE 2: We recommend always restoring the DLM to factory defaults and
reentering all settings in this procedure. This guarantees the DLM is in a
known condition.
3. For connections other than to a computer where the data rate (Baud Rate) and data
format can be determined from the “AT” command the DLM will need to be set to the
correct data rate and data format. Depending on the data rate of your connection
enter one of the following command strings:
a. 19200 bps: AT$SB19200
b. 9600 bps: AT$SB9600
c. 1200 bps: AT$SB1200
d. 300 bps: AT$SB300

Getting Started
Dialup / Leased Line Modem 10
4. Depending on the data format of your connection enter one of the following
command strings:
a. 8 data bits, no parity, 1 stop bit: AT$EB0
b. 8 data bits, even or odd parity, 1 stop bit: AT$EB1#P1
c. 8 data bits, no parity, 2 stop bits: AT$EB1#P2
d. 8 data bits, even or odd parity, 2 stop bits: AT$EB1#P0
e. 7 data bits, no parity, 1 stop bit: AT$EB0
f. 7 data bits, even or odd parity, 1 stop bit: AT$EB0
g. 7 data bits, no parity, 2 stop bits: AT$EB0
h. 7 data bits, even or odd parity, 2 stop bits: AT$EB1#P0
5. If using 3 wire RS232 or if hardware handshaking is not supported enter: AT&K0
6. if using 3 wire RS232 or if DTR is not available form your device enter: AT&D0
7. Save settings: AT&W0
8. You are done configuring your DLM. You may test the configuration by dialing out to
another modem or DLM or by dialing into the DLM.

Getting Started
Dialup / Leased Line Modem
11
Setting DLM for Leased-Line Operation
When the DLM is used with a Leased-Line one DLM must be set up to “originate” the
connections and the other DLM set up to “answer”. With the exception of the &L1 and &2
commands described in step 6 below the commands to set up the DLM will be the same.
The following procedure will set up the DLM to automatically connect without any intervention
from either connected device. You do not need to have any device connected to the RS232
port.
Each of the following commands will be entered then followed with a carriage return (Enter
Key). After entering each command wait for the “OK” response.
1. Turn on the DLM and as soon as the “DSR” and “CTS” lights turn on enter: AT%DC0
NOTE 1: You may not get a response from this command. The leased line
configuration disables the response to commands as well as the echoing of
characters.
NOTE 2: When used with Leased-Lines the DLM will be set up to ignore any
commands. To break out of this mode the “%DC0” command must be sent
within the first 10 seconds after power up.
2. Reset the DLM to its factory defaults by entering: AT&F0
NOTE 1: You will get an “OK” response from this command.
NOTE 2: We recommend always restoring the DLM to factory defaults and
reentering all settings in this procedure. This guarantees the DLM is in a
known condition.
3. Depending on the data rate of your connection enter one of the following command
strings:
a. 19200 bps: AT$SB19200+MS=V32B,0,0,19200,0,19200
b. 9600 bps: AT$SB9600+MS=V32,0,0,9600,0,9600
c. 1200 bps: AT$SB1200+MS=V22,0,0,1200,0,1200
d. 300 bps: AT$SB300+MS=V21,0,0,300,0,300
4. Depending on the data format of your connection enter one of the following command
strings:
a. 8 data bits, no parity, 1 stop bit: AT$EB0
b. 8 data bits, even or odd parity, 1 stop bit: AT$EB1#P1
c. 8 data bits, no parity, 2 stop bits: AT$EB1#P2
d. 8 data bits, even or odd parity, 2 stop bits: AT$EB1#P0
e. 7 data bits, no parity, 1 stop bit: AT$EB0
f. 7 data bits, even or odd parity, 1 stop bit: AT$EB0
g. 7 data bits, no parity, 2 stop bits: AT$EB0
h. 7 data bits, even or odd parity, 2 stop bits: AT$EB1#P0

Getting Started
Dialup / Leased Line Modem 12
5. Set DTR control and Hardware handshaking.
a. If hardware handshaking is not required enter: AT&D0&K0
b. If hardware handshaking is required enter: AT&D0&K1
6. Set the Leased-Line Mode:
a. Originating DLM: AT&L1
b. Answering DLM: AT&L2
7. Set inactivity timer:
The inactivity timer provides a failsafe in case communications is lost. When
communications is lost the DLM will disconnect after the specified number of minutes
then immediately attempt to reconnect.
a. If communications will be continuous: AT\T1
b. If communications will be slower than 1 minute per data transfer but less 254
minutes enter: AT\Tn
Where “n” is the data transfer rate in minutes plus 1. (EG If transfer rate is 5
minutes then enter “AT\T6”.
8. Disable echoing of characters and the displaying of result codes: ATE0Q1
NOTE: You will not get an “OK” response from this or the following command.
Disabling the echoing of characters and displaying of result codes will
prevent the DLM from interfering with the connected devices by introducing
random characters into the data transferred. Leaving the result codes
enabled will however provide information about the connection which can
be useful for diagnosing connection problems.
9. Disable AT commands and save settings: AT%DC1&W0
10.You are done configuring your DLM. You may test the configuration by connecting
two DLM’s together using a standard RJ-11 modular telephone cable. When set up
for Lease Line operation you do not need a telephone line. The DLMs will connect on
their own without any equipment connected to their RS232 ports.

Configuration
Dialup / Leased Line Modem
13
Configuration
To modify the configuration of a DLM the following will be required:
1. Computer with an available RS232 “COM” port.
2. Terminal Emulator such as Hyper Terminal.
3. Straight through RS232 cable to connect your computer to the DLM.
4. 12 to 30 volt power supply. The DLM typically draws 170 mA @12 VDC.
5. The Dial-Up / Leased-Line Modem (DLM).
The following instructions assume you are familiar with your terminal emulator program and
how to connect the DLM to your computer. See the Hardware Installation section for
instructions on connecting the DLM to your computer.
The DLM uses “AT” commands like many internal and external modems used with
computers. Like other modems some of the AT commands are standard while others are
specific to the manufacture.
All commands except the command to enter the command mode must be prefixed by “AT”.
The following sections describe the commands you are most likely need to modify. A
complete list is available from AGM Electronics Inc.
Entering Command Mode
When used with Dial-Up connections the escape character sequence of “+++” will switch
form the data mode to the command mode.
When used with Leased-Lines, the DLM has a 10 second window after power up during
which the DLM will always respond to commands. There is also a 30 second delay between
power up and when the DLM enters Leased-Line mode. Use the “%DC0” to allow
commands beyond the first 10 seconds and “&L0” command to disable the Leased-Line
mode.
NOTE: We recommend always restoring the DLM to factory defaults and reentering all
settings in the Getting Started Section. This guarantees the DLM is in a known
condition. The commands in this section are to provide a better understanding of
the commands used for setting up the DLM and to provide information for
advanced modem uses in setting up custom configurations.

Configuration
Dialup / Leased Line Modem 14
Common Commands
The following are the commands most commonly used in setting up your DLM.
Answer (A)
Enter “ATA” to immediately answer an incoming call when in Dial-Up operation.
Normally this command is unnecessary as the default setting for the DLM is to answer
on the first ring. Use register S0 to change when the DLM will automatically answer.
Dial (D)
Enter “ATD” followed by the phone number to dial the phone number when in Dial-Up
operation.
Echo Character (E) Command
Command characters Echoed ATE1
Command characters Not Echoed ATE0
Hang Up (H0)
Enter “+++” wait for “OK then enter “ATH0” to hand up the phone line.
Monitor Speaker (M)
Command
On until Connected ATM1
Always Off ATM0
Always On ATM2
Result Codes Enable (Q)
Command
Enabled ATQ0
Disabled ATQ1
Result Codes Format (V)
Command
Numeric ATQ0
Words ATQ1
Carrier Detect (&C) Command
DCD On When Carrier Detected AT&C1
DCD Always On AT&C0

Configuration
Dialup / Leased Line Modem
15
Data Terminal Ready DTR Control (&D)
Command
Hangs Up when DTR Drops AT&D2
DTR Ignored
(Use for 3 Wire RS232) AT&D0
Enters Command Mode,
Remains Connected AT&D1
Load Factory Settings (&F0)
Enter “AT&F0” to restore DLM to factory defaults.
Flow Control (&K) Command
Flow Control Disabled
(Use for 3 Wire RS232) AT&K0
Hardware CTS/RTS Flow Control AT&K3
Software XON/XOFF Flow Control AT&K4
Leased-Line (&L) Command
Dial-Up Operation AT&L0
Leased-Line (Originate) AT&L1
Leased-Line (Answer) AT&L2
NOTE:For Leased-Line operation one DLM must be set for Originate and the other must
be set forAnswer.
DSR Control (&S) Command
DSR Always On AT&S0
DSR On only during connection AT&S1
Display Configuration Settings (&V)
Enter “AT&V” to display the current modem configuration settings.
Save Changes (&W0)
Enter “AT&W0” to save the changes in the DLM non-volatile memory.
AT Command Control (%DC)
Command
AT Commands Enabled AT%DC0
AT Commands Disabled AT%DC1

Configuration
Dialup / Leased Line Modem 16
NOTE: The DLM will respond to a “AT%DC0” command for
10 seconds after power up.
Inactivity Timer (\T) Command
Inactivity Timer Disabled AT\T0
Inactivity Timer 1 Minute AT\T1
Inactivity Timer “n” Minutes AT\Tn
Data Format ($EB) and (#P)
Data Formats supported by the DLM will use either 10 or 11 bits. These bits included
the start, stop, data and parity bits. $EB command set the number of bits and #P
command sets the parity for data formats using 11 bits. The following table indicates
the command required to set the DLM to supported data format.
Data Format Command
8 data, no parity, 1 stop AT$EB0
8 data, even parity, 1 stop AT$EB1#P2
8 data, odd parity, 1 stop AT$EB1#P1
8 data, no parity, 2 stop AT$EB1#P0
7 data, no parity, 1 stop AT$EB0
7 data, even parity, 1 stop AT$EB0
7 data, odd parity, 1 stop AT$EB0
7 data, no parity, 2 stop AT$EB0
7 data, even parity, 2 stop AT$EB0
7 data, odd parity, 2 stop AT$EB1#P0
Serial Port Baud Rate ($SB)
Baud Rate Command
300 AT$SB300
1200 AT$SB1200
2400 AT$SB2400
4800 AT$SB4800
9600 AT$SB9600
19200 AT$SB19200
38400 AT$SB38400
57600 AT$SB57600
115200 AT$SB115200