Siemens SIMATIC NET MODEM MD720 System Manual

Preface, Contents

Introduction

1

Inserting the SIM card

2

Connecting the device and
switching on the device

3

MODEM MD720 in Terminal
Mode

4

MODEM MD720 in OPC Mode

5

Service function

6

Technical Data

7

Glossary

Release 07/2013

SIMATIC NET

GPRS/GSM-Modem
MODEM MD720

System manual

DRAFT

Safety Guidelines

This manual contains notices you have to observe in order to ensure your personal safety, as well as to prevent
damage to property. The notices referring to your personal safety are highlighted in the manual by a safety alert
symbol, notices referring only to property damage have no safety alert symbol. These notices shown below are
graded according to the degree of danger.

!

Danger

indicates that death or severe personal injury will result if proper precautions are not taken.

!

Warning

indicates that death or severe personal injury may result if proper precautions are not taken.

!

Caution

with a safety alert symbol, indicates that minor personal injury can result if proper precautions are not taken.

Caution

without a safety alert symbol, indicates that property damage can result if proper precautions are not taken.

Notice

indicates that an unintended result or situation can occur if the corresponding information is not taken into
account.

If more than one degree of danger is present, the warning notice representing the highest degree of danger will
be used. A notice warning of injury to persons with a safety alert symbol may also include a warning relating to
property damage.

Qualified Personnel

The device/system may only be set up and used in conjunction with this documentation. Commissioning and
operation of a device/system may only be performed by qualified personnel. Within the context of the safety notes
in this documentation qualified persons are defined as persons who are authorized to commission, ground and
label devices, systems and circuits in accordance with established safety practices and standards.

Prescribed Usage

Note the following:

!

Warning

This device may only be used for the applications described in the catalog or the technical description and only in
connection with devices or components from other manufacturers which have been approved or recommended by
Siemens. Correct, reliable operation of the product requires proper transport, storage, positioning and assembly
as well as careful operation and maintenance.

Trademarks

All names identified by ® are registered trademarks of the Siemens AG. The remaining trademarks in this

publication may be trademarks whose use by third parties for their own purposes could violate the rights of the
owner.

Disclaimer of Liability

We have reviewed the contents of this publication to ensure consistency with the hardware and software
described. Since variance cannot be precluded entirely, we cannot guarantee full consistency. However, the
information in this publication is reviewed regularly and any necessary corrections are included in subsequent
editions.

Siemens AG

Postfach 48 48
90437 NÜRNBERG
DEUTSCHLAND

Release 05/2006

Copyright © Siemens AG 2013
Technical data subject to change

2

!

Warning

The power supply unit to supply the MODEM MD720 must comply with NEC Class 2
circuits as outlined in the National Electrical Code (ANSI/NFPA 70) only.

General

The product MODEM MD720 complies with European standard EN60950-1 Safety of
Information Technology Equipment.
Read the installation instructions carefully before using the device.
Keep the device away from children, especially small children.
The device must not be installed or operated outdoors or at damp locations.
Do not operate the device if the connecting leads or the device itself are damaged.

External power supply

Use only an external power supply which also complies with EN60950-1. The output
voltage of the external power supply must not exceed 30VDC. The output of the
external power supply must be short-circuit proof.

When connecting to a battery or accumulator, make sure that an all-pole circuit­breaker (main battery switch) with sufficient selectivity and a fuse with sufficient
selectivity (e.g 32 V, 3A) are provided between the device and the battery or
accumulator.

Please pay regard to section 7 Technical Data of the system manual, as well as the
installation and utilization regulations of the respective manufacturers of the power
supply, the battery or the accumulator.

Handling cables

Never pull a cable connector out of a socket by its cable, but pull on the connector
itself. Cable connectors with screw fasteners (D-Sub) must always be screwed on
tightly. Do not lay the cable over sharp corners and edges without edge protection. If
necessary, provide sufficient strain relief for the cables.

For safety reasons, make sure that the bending radius of the cables is observed.
Failure to observe the bending radius of the antenna cable results in the deterioration

of the system's transmission and reception properties. The minimum bending radius
static must not fall below 5 times the cable diameter and dynamic below 15 times the
cable diameter.

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!

Warning

Never use the device in places where the operation of radio devices is prohibited. The
device contains a radio transmitter which could in certain circumstances impair the
functionality of electronic medical devices such as hearing aids or pacemakers. You
can obtain advice from your physician or the manufacturer of such devices. To prevent
data carriers from being demagnetized, do not keep disks, credit cards or other
magnetic data carriers near the device.

!

Warning

The emission limits as recommended by the Commission on Radiological Protection
(13/14 September 2001) must be observed.

Caution

The use of an outdoor antenna without adequate additional protection circuits is not
allowed. Installation must be done by a qualified person and in accordance to nationa
regulations.

Radio device

Installing antennas

Installing an external antenna

FCC Part 15

This equipment has been tested and found to comply with the limits for a Class A
digital device, pursuant to Part 15 of the FCC Rules. These limits are designed to
provide reasonable protection against harmful interference in a residential installation.
This equipment generates, uses and can radiate radio frequency energy and, if not
installed and used in accordance with the instructions, may cause harmful interference
to radio communications. However, there is no guarantee that interference will not
occur in a particular installation. If this equipment does cause harmful interference to
radio or television reception, which can be determined by turning the equipment off
and on, the user is encouraged to try to correct the interference by one or more of the
following measures:

 Reorient or relocate the receiving antenna.
 Increase the separation between the equipment and receiver.
 Connect the equipment into an outlet on a circuit different from that to which

the receiver is connected.

 Consult the dealer / installer or an experienced radio/TV technician for help.

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Caution

Typically, the antenna connected to the transmitter is an omni-directional antenna with
0dB gain. Using this antenna the total composite power in PCS mode is smaller than 1
watt ERP.
The internal / external antennas used for this mobile transmitter must provide a
separation distance of at least 20 cm from all persons and must not be co-located
or operating in conjunction with any other antenna or transmitter."

Caution
This is a class B equipment. This equipment can disturb other electric equipment in

living areas; in this case the operator can be demanded to carry out appropriate
measures.

FCC Part 15.19

This device complies with Part 15 of the FCC Rules. Operation is subject to the
following two conditions:

1. this device may not cause harmful interference, and

2. this device must accept any interference received, including interference that
may cause undesired operation.

FCC Part 15.21

Modifications not expressly approved by this company could void the user's authority
to operate the equipment.

Installation by qualified personnel only

You may only use the MODEM MD720 with an antenna of the MODEM MD720
accessory program.

The installation of the MODEM MD720 and the antenna as well as servicing is to be
performed by qualified technical personnel only. When servicing the antenna, or
working at distances closer than those listed below, ensure the transmitter has been
disabled.

RF Exposure mobile

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Caution

Please note that data packets exchanged for setting up connections, reconnecting,
connect attempts (e.g. Server switched off, wrong destination address, etc.) as well as
keeping the connection alive are also subject to charge.

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Preface

Purpose of this documentation

This documentation will support you on your way to successful application of
MODEM MD720. It will introduce you to the topic in clear and
straightforward steps and provide you with an overview of the hardware of
the MODEM MD720 GSM/GPRS modem. This documentation will help you
during installation and commissioning of SINAUT GSM/GPRS modem and
explains the diagnostics and service options available.

Validity of the documentation

This manual relates to the following product versions

 GPRS/GSM modem MD720 hardware release 1.x

SIMATIC Technical Support

You can contact Technical Support for all A&D products

 Phone: [phone]
 Fax: [phone]

You will find further information on our Technical Support on the Web at

http://www.siemens.com/automation/service

Service & Support on the Internet

In addition to our documentation services, you can also make use of all our
knowledge on the Internet:

http://www.siemens.com/automation/service&support

Here, you will find:

 Up-to-date product information (Updates), FAQs (Frequently Asked

Questions), Downloads, Tips and Tricks.

 The Newsletter keeps you constantly up to date with the latest

information on the products you use.

 The Knowledge Manager will find the documents you need.
 In the Forum, users and specialists exchange information and

experience.

 You can find your local contact for Automation & Drives in our contacts

database.

 You will find information on local service, repairs, spares and much more

under the rubric "Service".

You will find the latest version of this documentation under the entry ID

22549543.

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Preface

Do you still have questions relating to the use of the products described in
the manual? If so, then please talk to your local Siemens contact.

You will find the addresses in the following sources:

 On the Internet at: http://www.siemens.com/automation/partner
 On the Internet at http://www.siemens.com/simatic-net specifically for

SIMATIC NET products

 In the catalog CA 01
 In the catalog IK PI specifically for SIMATIC NET products

SIMATIC training center

To familiarize you with the systems and products, we offer a range of
courses. Please contact your regional training center or the central training
center in

D-90327 Nuernberg.

Phone: [phone]

http://www.sitrain.com

SIMATIC NET training center

For courses specifically on products from SIMATIC NET, please contact:

SIEMENS AG

Siemens AG, A&D Informations- und Trainings-Center

Dynamostr. 4

D-68165 Mannheim

Phone: [phone]

Fax: [phone]

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Contents

Preface .......................................................................................................................................... 7

1 Introduction ................................................................................................................... 11

2 Inserting the SIM card .................................................................................................. 13

3 Connecting the device and switching on the device ................................................ 14

4 MODEM MD720 in Terminal Mode ............................................................................. 19

4.1 Terminal mode activation................................................................................... 19

4.2 Operating requirements in Terminal Mode: GPRS subscriber contract ............ 20

4.3 Functions of the LEDs in Terminal Mode .......................................................... 20

4.4 Terminal mode operation ................................................................................... 21

4.5 Entering AT commands ..................................................................................... 22

4.6 Use AT commands ............................................................................................ 24

4.7 Supported AT commands in Terminal Mode ..................................................... 26

5 MODEM MD720 in OPC Mode ..................................................................................... 53

5.1 OPC Mode activation ......................................................................................... 54

5.2 Operating requirements in OPC Mode: GPRS subscriber contract .................. 54

5.3 Functions of the LEDs in OPC Mode ................................................................. 55

5.4 PIN in OPC-Mode .............................................................................................. 56

5.5 Log in to SINAUT MICRO SC ............................................................................ 58

6 Service functions .......................................................................................................... 59

6.1 Switching between Terminal mode and OPC Mode .......................................... 59

6.2 Getting the current settings and values ............................................................. 61

6.3 Load factory defaults ......................................................................................... 62

7 Technical Data .............................................................................................................. 63

Glossary ..................................................................................................................................... 67

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Contents

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1

Notice

You will find further information about the Terminal Mode and its use in
combination with TIM devices of the SINAUT ST7 system in the system manual of
the SINAUT ST7.

The MODEM MD720 has two different operation modes:

 Terminal Mode
 OPC Mode

The functional range and the functionality of the device are different in both modes.
The change between OPC Mode and Terminal Mode (refer to page 19 or page 54)
forces a restart of the device.

Terminal mode

The MODEM MD720 establishes radio data connections via a GSM network
(Global System for Mobile Communication).

 using modem connections via CSD (Circuit Switched Data),
 by sending SMS (Short Message Service).

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Introduction

Notice

You will find information about the OPC Mode in the system manual of the SINAUT
MICRO SC.

OPC-Modus

The MODEM MD720 transmits data over via a GSM radio network (Global System
for Mobile Communication).

 using GPRS (General Packet Radio Service) between S7-200 devices and an

 using SMS from a S7-200-device to any remote station, which can receive

Therefore the MODEM MD720 will be configured by program building blocks of the
connected PLC. The MODEM MD720 establishes autonomous the radio data
connection via GPRS between a S7-200 device and the OPC server SINAUT
MICRO SC.

OPC server SINAUT MICRO SC,

SMS.

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2

Notice

 The device must be switched off when you insert or change the SIM card.
 A plug-in SIM card (ID-000) is used.

Changing the SIM card

If you change the SIM card, please do not forget to update also the PIN number in
your application.

If you use a lot of SIM cards it can be helpful to set all PINs to the same PIN
number. You can do this i.e. by using a mobile phone. Please observe the security
requirements of your organization.

To insert the SIM card proceed as follows:

1. Make sure that the device is disconnected from the supply voltage.

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the device

3

1

Connector for supply voltage DC 24 V

2

Interface X1 (RS232) for the application or a service PC

3

SET button

4

LEDs: S (Status), Q (Quality), C (Connect)

5

Antenna connector

6, 9

Fixation for top rail mounting

7

SIM card holder tray

8

Button to access the SIM card

Connectors and LEDs

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Antenna

The antenna connector – SMA socket - is situated on the upper part of the front.
Impedance: approx. 50 Ohm

Caution

Please use only antennas of the MODEM MD720 accessory program. Other
antennas may disturb the product characteristics and may even cause defects.

Connectors for current supply

The screw terminals on the top of the device are for connecting the current supply:
24 V DC voltage (nominal), Ityp. 165mA at 24V. (Please also refer to chapter 7
Technical Data.) Both screw terminals on the left (24V) are internally connected,
see Fehler! Verweisquelle konnte nicht gefunden werden.. Both screw
terminals on the right (0V) are internally connected.

Connecting the device and switching on the device

.

Switching on

The devices switch on as soon as the operating voltage is supplied.

Functions of the LEDs

The MODEM MD720 has three LEDs, which are used to indicate the device
status. The function of the LEDs is different in terminal and OPC Mode. You will
find the explanation of the function

● in Terminal Mode in chapter 4.3 Functions of the LEDs in Terminal Mode and

● in OPC Mode in chapter 5.3 Functions of the LEDs in OPC Mode.

Serial interface X1

For data transmission:

Connect the application (e.g. machine, vending machine, sensor, computer) with
the interface X1 of the MODEM MD720. To connect, use a RS-232 cable.

If the application has a different interface, e.g. CAN, PPI cable or a different
industry bus, a commercially available interface converter can be connected
between it and the MODEM MD720.

OR

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Connecting the device and switching on the device

For configuration and service:

Connect the service PC via its serial interface (COM port). To connect, use a RS­232 cable.

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The SET button

Pushing the SET button

LED Status

Function

during operation for less
than 2 seconds



The LED „S“ (Status)

begins to light

Dump of current
settings and values
issued via the RS232
interface

during operation for 2-4
seconds



The LED „Q“ (Quality)

begins to light

Service mode to
download a new
firmware

during operation for more
than 4 seconds



Die LED „C“

(Connect) begins to
light

Load factory settings

By pushing the SET button for a certain period of time, you can configure the
device or activate different service modes.

Connecting the device and switching on the device

Top-hat rail mounting

The MODEM MD720 is suitable for top-hat rail mounting on DIN EN 50022 rails. A
corresponding bracket can be found at the rear of the device.

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Connecting the device and switching on the device

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4

In the Terminal Mode the MODEM MD720 operates like a GSM modem, which is
controlled by AT commands.

Supported are
 incoming and outgoing GSM data connections with 9600 bps with modems

being connected to the GSM network, the ISDN or the analogue telephone
network,

 sending of SMS (Short Message Service).

4.1 Terminal mode activation

Terminal mode is the factory default setting

The MODEM MD720 supports two fundamental operation modes:

 Terminal Mode,
 OPC Mode.

The MODEM MD720 is delivered by the factory with activated Terminal Mode.

Switching from OPC Mode into the Terminal Mode

If it is necessary to switch a manually the MODEM MD720 from OPC Mode into
the Terminal Mode, you will find the instructions for this in the chapter Switching
between Terminal mode and OPC Mode.

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MODEM MD720 in Terminal Mode

LED

Status

Meaning

S, Q, C
combined

Fast lighting in sequence

Boot procedure

Synchronous slow blinking

Service mode

Slow lighting in sequence

Update

Synchronous fast blinking

Error

S (Status)

Blinks slowly

Device waiting for PIN input

Blinks fast

PIN error / SIM error

Q (Quality)

Blinks slowly

Booking into GSM network

1x intermittent blinking

Field strength not sufficient

2x intermittent blinking

Field strength sufficient

3x intermittent blinking

Field strength medium

ON permanently

Field strength high

OFF

Waiting for PIN input

C (Connect)

Blinks

Terminal mode active

4.2 Operating requirements in Terminal Mode: GPRS
subscriber contract

To use the MODEM MD720 in Terminal Mode it is required:
 SIM card of a GSM network operator including CSD data service 9600 Bit/s

and an extra telephone number for data calls,

 Availability of a GSM network.

4.3 Functions of the LEDs in Terminal Mode

The device has 3 LEDs, which indicates the current operation status:
S (Status) Q (Quality) C (Connect)

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Blinks slowly: 1 time each second
Blinks fast: 4 times each second

4.4 Terminal mode operation

To operate the device the PIN (PIN = Personnel Identification Number) of the
inserted SIM card must be known. In the Terminal Mode the PIN is not stored in
the MODEM MD720. The PIN must be set again every time the device is turned­on.

● The PIN is set by AT commands.
If you use a PIN-less SIM card the PIN request is skipped.

Control by the application

Usually the application or the application software, which you execute on a
connected computer, will control the MODEM MD720. So wits, the commands to
establish or to disconnect a data connection via the GSM network, are given by the
application to the device. For this purpose the application and the device
communicates using AT commands, like other types of modems. The sending of
SMS is handled in the same way.

MODEM MD720 in Terminal Mode

Direct control using AT command

You can also enter manually AT commands to control the MODEM MD720. In this
case use any terminal program (Refer to Working with a terminal program.)

Or you write your own communication program which is adapted especially to your
purposes.

Enter the PIN first

Please enter the PIN first before any other AT commands. Until a PIN has been
entered most AT commands will be answered with ERROR.

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MODEM MD720 in Terminal Mode

4.5 Entering AT commands

The MODEM MD720 is controlled by AT commands, which are entered either by
the connected application or manually by terminal program.

Working with a terminal program

To be able to control the device directly via AT commands, use a terminal program,
e.g. HyperTerminal.

Note the following settings:
Make the connection: COM port to which the device is connected
Speed: 19200 Bit/s
Data bits: 8
Parity: No
Stop bits: 1
Duplex: Full

PIN in Terminal-Mode

Enter the PIN

If the LED S blinks slowly (1 time each second), the MODEM MD720 waits for a
PIN entry.

In Terminal-Mode the PIN need to be entered using the AT command AT+CPIN.
Example:

The number of permitted trial to enter the PIN is limited by the SIM card.

Command: at+cpin="0000“ // Input incl. “ “
Response: OK

Normally three attempts are allowed, i.e. you may enter two times back-to-back a
wrong PIN, at the third attempt the right PIN must be entered, otherwise the SIM
will be blocked. In this case the SIM card can only be unblocked by entering the
PUK.

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The LED S (status) blinks fast

If the modem blinks fast (4 times each second), either the SIM card was not
detected correctly or the SIM card is PUK-blocked, because a wrong PIN has been
entered too often.

Please check, if the SIM card is inserted correctly (see chapter 2 Inserting the SIM
card).

Please check, if the SIM card is PUK-blocked. Insert the SIM card into a common
mobile phone. The mobile phone will display, if the SIM card is PUK-blocked. If the
SIM card is PUK-blocked, please enter the PUK and then a PIN. You can use a
common mobile phone to do this.

Before you enter again the SIM card into the MODEM MD720, please investigate
why the SIM card has been PUK-blocked: Which PIN have you entered or which
PIN has your application sent to the MODEM MD720?

Changing the SIM card

MODEM MD720 in Terminal Mode

If you change the SIM card, please do not forget to update also the PIN number in
your application.

If you use a lot of SIM cards it can be helpful to set all PINs to the same PIN
number. You can do this i.e. by using a mobile phone. Please observe the security
requirements of your organization.

PIN-less SIM cards

The device operates also with SIM cards, which PIN check is deactivated. In this
case the PIN check is skipped and the device will immediately try to attach the
GSM network.

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MODEM MD720 in Terminal Mode

4.6 Use AT commands

Syntax

The AT command language is a standard for controlling modems. It is line­orientated. Each command line begins with AT (for ATtention), followed by the
actual command, and ends with (Enter key).

Example: ATD444444¬

means: dial (D for Dial) 444444
There are only two exceptions to this rule:

The command +++ to switch to Command Phase (see below) and the command

A/ with which the last command line is repeated.

Command phase, Transparent phase

The device accepts AT commands only when it is in Command Phase.
It is in Command Phase,

 when there is no active connection,
 when the sequence Pause +++ has been entered during a connection.

The device does not accept AT commands when it is in Transparent Phase.
It is in Transparent Phase,

 when there is an active connection,
 when the device has been switched to Command Mode during an active

connection with +++ and then switched back to Transparent Mode with ATO.

Enabling/disabling local echo

To see your entries on the screen, you may have to enable the local data echo. To do
so, enter the following command: ATE1

To disable the local data echo, enter the following command: ATE0

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Enter the PIN

Command: at+cpin="0000“
Response: OK

Network-Status request

Command: at+creg?
Response: +CREG: 0,1

Firmware Version request

Command: ati3
Response: SIE3171 MODEM MD720 V.1.7.00 19.05.2006

MODEM MD720 in Terminal Mode

CSD call outgoing:

Command: atd0123456789
Response: CONNECT

CSD call incoming:

Response: RING
Command: ata
Response: CONNECT

Sending SMS:

Command: at+cmgf=1
Response: OK
Command: at+cmgs="phonenumber",145
Command: >Text of the SMS max. 160 characters; End and sending with Strg-

Z

Response: +CMGS: 251 // value is an example
OK

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MODEM MD720 in Terminal Mode

+++

Switch from data mode to command mode

Execute command

Command:

+++

Response:

This command is only available during data calls. The +++ characters sequence causes
to cancel de data flow over the AT interface and switch to command mode. This allows to
enter AT commands while maintaining the data connection to the remote device.

Parameter:

-

Notice:

To return to data mode, use the ATO command
Line does not need to end with terminating character, i.e. <CR><LF>

A/

Repeat previous command line

Executive command

Command:

A/

Response:

Depend on the previous command

Parameter:

-

Notice:

Line does not need to end with terminating character, i.e. <CR><LF>

ATA

Answer a call

Executive command

Command:

ATA

Response:

CONNECT[<text>] Data connection established
OK Voice connection established or if cancellation of the

command

NO CARRIER Response if no connection

Parameter:

-

Notice:

See ATX for setup of the CONNECT message.

4.7 Supported AT commands in Terminal Mode

All AT commands being not listed below will be answered with OK by the device,
but the command will not be executed.

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MODEM MD720 in Terminal Mode

ATD

Mobile originated Call to dial a number

Executive command

Command:

ATD[<n>]

Response:

The connection cannot be established:
NO DIALTONE
BUSY
NO CARRIER
NO ANSWER
Data connection successfully connected:
CONNECT[<text>]

Parameter:

<n>:
String of dialing digits and optionally V.25ter modifiers (dialing digits): 0-9, * , #, +, A, B, C

Notice:

-

ATE

Local Echo On/Off

Executive command

Command:

ATE[<value>]

Response:

OK

Parameter:

<value>:
0 Local Echo off
1 Local Echo on <Default>

Notice:

This setting determines whether or not the device echoes characters received from
application during command state

ATH

Disconnect existing connection

Executive command

Command:

ATH

Response:

OK

Parameter:

-

Notice:

On this command, all calls in progress are ended.
If a call is in progress, it is necessary to switch into the command phase by +++ before

entering commands.

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MODEM MD720 in Terminal Mode

ATI

Request identification information

Read command

Command:

ATI[<value>]

Response:

<text> (depends on <value>)
OK

Parameter:

<value>:
none: Product name and Firmware Version
0: Product name and Firmware Version
1: Product name, Interface, Mode
3: Product name and Firmware Version

Notice:

<text> may take more than one line

ATO

Switch from command mode to data mode

Executive command

Command:

ATO[n]

Response:

Device returns to data mode from command mode:
CONNECT <text>
If connection is not successfully resumed
NO CARRIER

Parameter:

<n>:
0 switch from command mode to data mode

Notice:

ATO corresponds to the +++ escape sequence.

ATQ

Set result code presentation mode

Executive command

Command:

ATQ[<n>]

Response:

OK (if <n> = 0)
Nothing (if <n> = 1)

Parameter:

<n>:
0: result codes transmitted by the device <Default>

1: no result code transmitted by the device

Notice:

Specifies whether or not the device transmits any result code to the application.
Information text transmitted in response is not affected by this setting.

ATS0?

Shows Automatic answering settings

Read command

Command:

ATS0?

Response:

<n>
OK

Parameter:

See ATS0=<n>

Notice:

-

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MODEM MD720 in Terminal Mode

ATS0

Configures Automatic answering

Executive command

Command:

ATS0=<n>

Response:

OK

Parameter:

<n>:
0: automatic answering deactivated <Default>
1-255: number of rings before automatically answering

Notice:

GSM networks usually generate only 8-12 RING. If S0 is set to a higher value, calls are
eventually not being answered.

ATV

Set result code format mode

Executive command

Command:

ATV[<value>]

Response:

0 When numeric mode is activated
OK When verbose mode is activated

Parameter:

<value>:
0 Information <text><CR><LF>
Result Code (short format): <numeric code><CR>
1 Information <CR><LF><text><CR><LF>
Result Code (long format): <CR><LF><verbose code><CR>

<Default>

Notice:

This parameter setting determines the contents of the header and trailer transmitted with
result codes and information responses.

Result codes numeric or verbose:
OK 0 Command executed, no error, Restart executed
CONNECT 1 Connection established
RING 2 Ring detected
NO CARRIER 3 Connection not established or interrupted
ERROR 4 Command not valid
NO DIALTONE 6 No dialtone, dialing not possible, wrong mode
BUSY 7 Remote station busy
CONNECT 2400/RLP 1 Connect at 2400 bps and Radio Link Protocol
CONNECT 4800/RLP 1 Connect at 4800 bps and Radio Link Protocol
CONNECT 9600/RLP 1 Connect at 9600 bps and Radio Link Protocol

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MODEM MD720 in Terminal Mode

AT\Q

Hardware Flow Control on/off

Executive command

Command:

AT\Q<n>

Response

OK

Parameter:

<n>:
0: Hardware Flow Control (RTS/CTS) off
3: Hardware Flow Control (RTS/CTS) on

Notice:

-

ATX

Set CONNECT result code Format und Call monitoring

Executive command

Command:

ATX[<value>]

Response:

OK

Parameter:

<value>:
0 : CONNECT result code only returned, dial tone and busy detection are both

disabled <Default>

1 : CONNECT<text> result code only returned, dial tone and busy detection are

both disabled
2 : same as 1
3 : same as 1
4 : same as 1

Notice:

The term “tone” is used in analogue telephone networks. The status “No dialtone” will
usually not appear, as soon as the device is booked into a GSM network. A Busy
message will be transmitted.

AT&C

AT&C Set circuit Data Carrier Detect (DCD) function mode

Executive command

Command:

AT&C[<value>]

Response:

OK

Parameter:

<value>:
0 : DCD line is always ON
1 : DCD line is ON in the presence of data carrier only. <Default>

Notice:

-

30 Fehler! Verweisquelle konnte nicht gefunden werden.

MODEM MD720 in Terminal Mode

AT&D

Set circuit Data Terminal Ready (DTR) function mode

Executive command

Command:

AT&D[<value>]

Response:

OK

Parameter:

<value>:
0: Device ignores status on DTR. <Default>
2: ON->OFF on DTR: Disconnect call, change to command mode. During state

DTR = OFF is auto-answer off.

Notice:

-

AT&F

Restore manufactory configuration

Executive command

Command:

AT&F

Response:

OK

Parameter:

<value>:
0: Restore parameters to manufactory values

Notice:

Restores the configuration of manufacturer of the following commands: ATE, ATQ, ATV,
ATX, AT&C, AT&D, AT\Q and ATS0.

AT&W

Save stored profile

Executive command

Command:

AT&W<n>

Response:

OK

Parameter:

<n>:
None Saving in Profile 0
0 Saving in Profile 0

Notice:

This command saves the current configuration in a non volatile memory of the commands
ATE, ATQ, ATV, ATX, AT&C, AT&D, AT\Q and ATS0. The configuration can be reloaded
with ATZ. Before the first saving the profile is the same as the default configuration.

See also AT&V.

AT&V

Display current configuration

Executive command

Command:

AT&V[<value>]

Response:

ACTIVE PROFILE:
<current configuration>
OK

Parameter:

<value>:
0: only active profile

Notice:

The configuration is a text string on multiple lines as shown in the example below. As it is
dependant on the manufactory and user set-up, it is impossible to list the exact number of
information given.

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MODEM MD720 in Terminal Mode

AT+CCLK

Clock

Test

Command:

+CCLK=?

Response:

OK

Read command

Command:

+CCLK?

Response:

+CCLK: <time>

Executive command

Command:

AT+CCLK=<time>

Response:

OK
+CME ERROR: <err>

Parameter:

<time>:
String variable; the format is "yy/MM/dd,hh:mm:sszz", with
yy: Year
MM: Month
dd: Day
mm: Minute
ss: Second
zz: Time zone, gives the difference between the local time and GMT, given in

quarters of an hour; the range of values is -47…+48. Example: 6th of may,

1994, 22:10:00 GMT+2 hours corresponds to "94/05/06,22:10:00+08"

Notice:

-

32 Fehler! Verweisquelle konnte nicht gefunden werden.

MODEM MD720 in Terminal Mode

AT+CRLP

Radio link protocol

Test

Command:

+CRLP=?

Response:

+CRLP: (list of supported <iws>s),(list of supported <mws>s),
(list of supported <T1>s),(list of supported <N2>s),<ver1>
,(list of supported <T4>s)

Read command

Command:

+CRLP?

Response:

+CRLP: <iws>,<mws>,<T1>,<N2>,<ver1>,<T4>

Executive command

Command:

AT+CRLP=<iws>[,<mws>[,<T1>[,<N2>[,<ver>[,<T4>]]]]]

Response:

OK

Parameter:

<ver>: RLP version number as Integer variable; Version number 0 indicates “RLP

version indication not available”
<iws>: Window size IWF to MS
<mws>: Window size MS to IWF
<T1>: Acknowledge timer T1
<N2>: Retransmission attempts N2
<T4>: Re-sequencing period T4 as Integer variable

Notice:

Default values and value ranges depend on RLP Version; refer GSM 04.22 [18].
T1 and T4 are in units of 10 ms.

Fehler! Verweisquelle konnte nicht gefunden werden. 33

MODEM MD720 in Terminal Mode

AT+CPIN

Enter PIN

Test

Command:

AT+CPIN=?

Response:

OK

Read command

Command:

AT+CPIN?

Response:

+CPIN: <code>

Executive command

Command:

AT+CPIN=<pin> [,<newpin>]

Response:

OK

Parameter:

<code>:
Values reserved by this device:

READY Device is not pending for any password
SIM PIN Device is waiting SIM PIN to be given
SIM PUK Device is waiting SIM PUK to be given. Also, a second pin, <newpin>, is

used to replace the old pin in the SIM and should thus be supplied

SIM PIN2 Device is waiting SIM PIN2 to be given (this <code> is recommended to

be returned only when the last executed command resulted in PIN2
authentication failure (i.e. +CME ERROR: 17); if PIN2 is not entered right
after the failure, it is recommended that ME does not block its operation)

SIM PUK2 Device is waiting SIM PUK2 to be given (this <code> is recommended to

be returned only when the last executed command resulted in PUK2
authentication failure (i.e. +CME ERROR: 18); if PUK2 and new PIN2 are
not entered right after the failure, it is recommended that ME does not
block its operation). Also, a second pin, <newpin>, is used to replace the

old pin in the SIM and should thus be supplied
PH-NET PIN ME is waiting personalization password to be given
<pin>, <newpin>:
String type value (8 characters max.)

Notice:

-

34 Fehler! Verweisquelle konnte nicht gefunden werden.

MODEM MD720 in Terminal Mode

AT+CSQ

Check Signal Quality

Test

Command:

AT+CSQ=?

Response:

+CSQ: (list of supported <rssi>s),(list of supported <ber>s)
OK

Response:

Command:

AT+CSQ

Response:

+CSQ: <rssi>,<ber>
OK

Parameter:

<rssi>:
0 -113 dBm or less
1 -111 dBm

2...30 -109... -53 dBm
31 -51 dBm or greater
99 not known or not detectable
<ber>:

0...7 as RXQUAL values in the table in GSM 05.08 [20] subclause 8.2.4
99 not known or not detectable

Notice:

The read command (AT+CSQ?) returns an error.

AT+CGSN

Request product serial number identification (IMEI) identical to GSN

Test

Command:

AT+CGSN=?

Response:

OK

Read command

Command:

AT+CGSN

Response:

<sn> (identification text for determination of the individual device)
OK

Parameter:

-

Notice:

-

Fehler! Verweisquelle konnte nicht gefunden werden. 35

MODEM MD720 in Terminal Mode

AT+CGDCONT Define PDP context

Test

Command:

AT+CGDCONT=?

Response:

+CGDCONT: (Range of supported <cid>s), <PDP_type>,,,(List of supported
<d_comp>s), (List of supported <h_comp>s)

Read command

Command:

AT+CGDCONT?

Response:

If +CGDCONT is set:
+CGDCONT: <cid>, <PDP_type>, <APN>,<PDP_addr>, <d_comp>, <h_comp>
If +CGDCONT is not set:
OK

Executive command

Command:

+CGDCONT=<cid> ,<PDP_type> ,<APN> ,<PDP_addr> ,<d_comp> ,<h_comp>

Response:

OK

Parameter:

<cid>: (Local) context identification parameter
<PDP_type>: Packet Data Protocol type
A string parameter which specifies the type of packet data protocol. Only IP Internet

Protocol - IETF STD 5) is supported.
<APN>: Access Point Name
A string parameter which is a logical name that is used to select the GGSN or the external

packet data network.
<PDP_address>:
A string parameter that identifies the MT in the address space applicable to the PDP. As

only IP is currently supported, it shall be an IP address.

If the value is null (“0.0.0.0” or 0), then a value may be provided by the TE during the PDP

startup procedure or, failing that, a dynamic address will be requested.
The read form of the command will continue to return the null string even if an address

has been allocated during the PDP startup procedure. The allocated address may be
read using the +CGPADDR command.

<d_comp>:
A numeric parameter that controls PDP data compression.
0: off (default and only value supported)
<h_comp>:
A numeric parameter that controls PDP header compression
0: off (default and only value supported)
<pd1>, … <pdN>:
Zero to N string parameters whose meanings are specific to the <PDP_type>

Notice:

The execute command specifies PDP context parameter values for a PDP context
identified by the (local) context identification parameter, <cid>. The number of PDP
contexts that may be in a defined state at the same time is given by the range returned by
the test command.

A special form of the set command, +CGDCONT= <cid> causes the values for context
number <cid> to become undefined.

36 Fehler! Verweisquelle konnte nicht gefunden werden.

MODEM MD720 in Terminal Mode

AT+CGATT GPRS Attach or Detach

Test

Command:

AT+CGATT=?

Response:

+CGATT: (list of supported <state>s)

Read command

Command:

AT+CGATT?

Response:

+CGATT: <state>

Executive command

Command:

+CGATT=<state>

Response:

OK

Parameter:

<state>:
Indicates the state of GPRS attachment
0: detached
1: attached

Notice:

-

AT+CIMI

Request international subscriber identity

Test

Command:

AT+CIMI=?

Response:

OK

Read command

Command:

AT+CIMI

Response:

<IMSI> (International Mobile Subscriber Identify)
OK

Parameter:

-

Notice:

-

Fehler! Verweisquelle konnte nicht gefunden werden. 37

MODEM MD720 in Terminal Mode

AT+CPAS

Phone activity status

Test

Command:

AT+CPAS=?

Response:

+CPAS: (list of supported <pas>s)
OK

Read command

Command:

AT+CPAS

Response:

+CPAS: <pas>
OK

Parameter:

<pas>:
0 ready (device allows commands from application)
1 unavailable (device does not allow commands from application)
2 unknown (device is not guaranteed to respond to instructions)
3 ringing (device is ready for commands from application, but the ringer is active)
4 call in progress (device is ready for commands from application, but a call is in

progress)

Notice:

-

38 Fehler! Verweisquelle konnte nicht gefunden werden.

MODEM MD720 in Terminal Mode

AT+CPMS

Preferred Message Storage

Test

Command:

AT+CPMS=?

Response:

+CPMS: (list of supported <mem1>s),(list of supported <mem2>s),(list of supported
<mem3>s),

OK

Read command

Command:

AT+CPMS?

Response:

+CPMS: <mem1>,<used1>,<total1>,<mem2>,<used2>,<total2>,<mem3>,
<used3>,<total3>

OK

Executive command

Command:

AT+CPMS= <mem1>,<mem2>,<mem3>

Response:

+CPMS: <used1>,<total1>,<used2>,<total2>,<used3>,<total3>
OK

Parameter:

The executive command selects the SMS storage <mem<x>>, being used to read, write,
etc.

<mem1>
Memory to be used for listing, reading and deleting of messages:

“SM” Message storage on SIM card
“ME” Message storage on device
“MT” Sum of message storage on SIM card and device

<mem2>
Memory to be used for writing and sending of messages:

“SM” Message storage on SIM card
“ME” Message storage on device
“MT” Sum of message storage on SIM card and device

<mem3>
Memory to be used for storage of received messages, if the routing to the connected

application is not possible. Refer to command AT+CNMI with parameter <mt>=2

“SM” Message storage on SIM card
“MT” Sum of message storage on SIM card and device

<usedx>
Number of messages currently stored in <memx>.
<totalx>
Number of messages currently which can be stored in<memx>.

Notice:

Example:
AT+CPMS=? +CPMS: ("ME","SM","MT")
OK
AT+CPMS? +CPMS: "ME",0,100
OK
AT+CPMS="ME" +CPMS: 0,100
OK
Until firmware version 1.6 inclusive, only the message storage “MT could be selected for

<mem3>.

Fehler! Verweisquelle konnte nicht gefunden werden. 39

MODEM MD720 in Terminal Mode

AT+CNUM

Subscriber number

Test

Command:

AT+CNUM=?

Response:

OK

Executive command

Command:

AT+CNUM

Response:

+CNUM: [<alpha1>],<number1>,<type1>[,<speed>,<service>[,<itc>]]
[<CR><LF>+CNUM: [<alpha2>],<number2>,<type2>[,<speed>,<service>
[,<itc>]]
[...]]
OK

Parameter:

<alpha>:
optional alphanumeric string associated with <number>; used character set should be the

one selected with command Select TE Character Set +CSCS
<number>:
string type phone number of format specified by <type>
<type>:
type of address octet in integer format (refer GSM 04.08 [8] subclause 10.5.4.7)

<speed>:
<service>:
service related to the phone number
0: asynchronous modem
1: synchronous modem
2: PAD Access (asynchronous)
3: Packet Access (synchronous)
4: voice
5: fax
also all other values below 128 are reserved by the present document

<itc>:
information transfer capability
0: 3.1kHz
1: UDI

Notice:

Action command returns the MSISDNs related to the subscriber (this information can be
stored in the SIM or in the ME)

The Read Command (AT+CNUM?) returns an error
Example:
AT+CNUM +CNUM: "TEL","0612345678",129
+CNUM: "","",255
+CNUM: "","",255
+CNUM: "","",255
OK

40 Fehler! Verweisquelle konnte nicht gefunden werden.

MODEM MD720 in Terminal Mode

AT+CBST

Select bearer service type

Read command

Command:

AT+CBST=?

Response:

+CBST: (list of supported <speed>s),(list of supported <name>s),(list of sup­ported <ce>s)
OK

Executive command

Command:

AT+CBST=[<speed> [,<name>[,<ce>]]]

Response:

OK

Parameter:

<speed>:
4 2400 bps (V.22bis)
6 4800 bps (V.32)
7 9600 bps (V.32)
68 2400 bps (V.110 or X.31 flag stuffing)
70 4800 bps (V.110 or X.31 flag stuffing)
71 9600 bps (V.110 or X.31 flag stuffing)
<name>:
0 data circuit asynchronous (UDI or 3.1 kHz modem)
1 Not supported
<ce>:
0 transparent
1 non-transparent

Notice:

Set command selects the bearer service <name> with data rate <speed>, and the
connection element <ce> to be used when data calls are originated.

AT+CMGD

Delete a SMS

Test

Command:

AT+CMGD=?

Response:

+CMS ERROR: <err>

Read command

Command:

AT+CMGD?

Response:

+CMS ERROR: <err>

Executive command

Command:

+CMGD=<index>

Response:

OK or +CMS ERROR: <err>

Parameter:

<index>
1 – n Memory location on the SIM card; n depends on the memory capacity of the

SIM card

<err> Error code

Notice:

-

Fehler! Verweisquelle konnte nicht gefunden werden. 41

MODEM MD720 in Terminal Mode

AT+CMGF

Select SMS message format

Test

Command:

AT+CMGF=?

Response:

+CMGF: (list of supported <mode>s)
OK

Read command

Command:

AT+CMGF?

Response:

+CMGF: <mode>
OK

Executive command

Command:

AT+CMGF=[<mode>]

Response:

OK

Parameter:

<mode>:
0 PDU mode
1 Text mode

Notice:

-

42 Fehler! Verweisquelle konnte nicht gefunden werden.

MODEM MD720 in Terminal Mode

AT+ CMGL

List SMS messages from preferred storage

Test

Command:

AT+CMGL=?

Response:

+CMGL: (list of supported <stat>s)
OK

Executive command

Command:

AT+CMGL[=<stat>]

Response:

In text mode (+CMGF=1) and successfully executed command and SMS-SUBMITs
and/or SMS-DELIVERs:

If <stat> = "REC READ" or "REC UNREAD"

+CMGL: <index>,<stat>,<oa/da>,<scts>,<length>
<CR><LF><data><CR><LF>
[+CMGL: <index>,<stat>,<oa/da>,<scts>,<length><CR><LF><data>
<CR><LF>[...]]

If <stat> = "STO UNSENT" or "STO SENT"

+CMGL: <index>,<stat>,<oa/da>,<length>
<CR><LF><data><CR><LF>
[+CMGL: <index>,<stat>,<oa/da>,<length><CR><LF><data>
<CR><LF>[...]]

In other cases:

+CMS ERROR: <err>

In PDU mode (+CMGF=0) and successfully executed command:

[+CMGL: <index>,<stat>,[<alpha>],<length><CR><LF><pdu>
[<CR><LF>+CMGL:<index>,<stat>,[<alpha>],<length><CR><LF><pdu>
[...]]]
OK

Fehler! Verweisquelle konnte nicht gefunden werden. 43

MODEM MD720 in Terminal Mode

Parameter:

<index>
integer type; value in the range of location numbers supported by the associated memory
<stat>
integer type (default 0: "REC UNREAD"); indicates the status of message in memory;

defined values:
0 "REC UNREAD" received unread message (i.e. new message)
1 "REC READ" received read message
2 "STO UNSENT" stored unsent message (only applicable to SMS)
3 "STO SENT" stored sent message (only applicable to SMS)
4 "ALL" all messages (only applicable to +CMGL command)
<oa/da>
GSM 03.40 TP-Originating-Address / TP-Destination-Address Address-Value field in

string format
<scts>
GSM 03.40 TP-Service-Centre-Time-Stamp in time-string format
<length>
integer type value indicating the length in characters of the message body <data>
<data>
GSM 03.40 TP-User-Data in text mode responses

Notice:

The execute command indicates the state <stat> of the preferred SMS storage <mem1>.

AT+CMGR

Read SMS message

Test

Command:

AT+CMGR=?

Response:

OK

Executive command

Command:

AT+CMGR=<index>

Response:

In text mode (+CMGF=1)
If command is executed successfully and SMS-DELIVER:
+CMGR: <stat>,<oa>,<scts>,<length>
<CR><LF><data><CR><LF>
If command is executed successfully and SMS-SUBMIT:
+CMGR: <stat>,<da>,<length>
<CR><LF><data><CR><LF>
In other cases:
+CMS ERROR: <err>
In PDU mode (+CMGF=0) and successfully performed command:
+CMGR: <stat>,[<alpha>],<length><CR><LF><pdu>
OK

Parameter:

Refer to +CMGL

Notice:

Execution command returns message with location value <index> from preferred
message storage <mem1>. Status of the message and entire message data unit <pdu> is
returned. If status of the message is 'received unread', status in the storage changes to
'received read'.

44 Fehler! Verweisquelle konnte nicht gefunden werden.

MODEM MD720 in Terminal Mode

AT+CMGS

Sending SMS

Test

Command:

AT+CMGS=?

Response:

OK

Executive command

Command:

In text modus (+CMGF=1):

+CMGS=<da>,<toda><CR>

> text is entered<ctrl-Z/ESC>

In PDU mode (+CMGF=0):

AT+CMGS=<length><CR> enter PDU <ctrl-Z/ESC>

Response:

In text mode (+CMGF=1) and successful sending:

+CMGS: 0

If sending fails:

+CMS ERROR: <err>

In PDU mode (+CMGF=0) and successful sending:

+CMGS: <mr>[,<ackpdu>]
OK

Parameter:

<da>:
Enter phonenumber with “ “
<toda>:
145: Enter phone number incl. country code, e.g. +49xxxxx for Germany
129: Enter phone number without country code
<mr>:
TP-Message-Reference in integer format

<ackpdu>

RP-User-Data element of RP-ACK PDU; format is same as for <pdu> in case of SMS, but
without 3G TS 24.011 [6] SC address field and parameter shall be bounded by double
quote characters like a normal string type parameter

<length>
Integer type value indicating in the text mode (+CMGF=1) the length of the message body

<data> > (or <cdata>) in characters; or in PDU mode (+CMGF=0), the length of the actual
TP data unit in octets (i.e. the RP layer SMSC address octets are not counted in the
length)

Notice:

- The device shall send a four character sequence <CR><LF><greater_than><space>

(IRA 13, 10, 62, 32) after command line is terminated with <CR>; after that PDU can
be given from application to the device

- the DCD signal shall be in ON state while PDU is given

- the echoing of given characters back from the device is controlled by V.25ter echo

command E

- the PDU shall be hexadecimal format (similarly as specified for <pdu>) and given in

one line; the device converts this coding into the actual octets of PDU

- when the length octet of the SMSC address (given in the PDU) equals zero, the

SMSC address set with command Service Centre Address +CSCA is used; in this
case the SMSC Type-of-Address octet shall not be present in the PDU, i.e. TPDU
starts right after SMSC length octet

- sending can be cancelled by giving <ESC> character (IRA 27)

- <ctrl-Z> (IRA 26) must be used to indicate the ending of PDU

Fehler! Verweisquelle konnte nicht gefunden werden. 45

MODEM MD720 in Terminal Mode

AT+CNMI

New SMS message indication

Test

Command:

AT+CNMI=?

Response:

+CNMI: (list of supported <mode>s), (list of supported <mt>s), (list of supported <bm>s),
(list of supported <ds>s), (list of supported <bfr>s) 2.

Read command

Command:

AT+CNMI?

Response:

+CNMI: <mode>,<mt>,<bm>,<ds>,<bfr>,OK

Executive command

Command:

AT+CNMI=[<mode>][,<mt>][,<bm>][,<ds>][,<bfr>]

Response:

OK

Parameter:

<mode>:
0: Buffer unsolicited result codes in the device. If device result code buffer is full,

indications can be buffered in some other place or the oldest indications may be
discarded and replaced with the new received indications.

1: Discard indication and reject new received message unsolicited result codes

when the link between the device and the connected application is reserved.
Otherwise forward them directly to the connected application.

2: Buffer unsolicited result codes in the device when the link between the device

and the connected application is reserved (e.g. in on-line data mode) and flush
them to the connected application after reservation. Otherwise forward them

directly to the connected application.
3: Not supported
<mt>:
0: No SMS-DELIVER indications are routed to the connected application.
1: If SMS-DELIVER is stored into device, indication of the memory location is

routed to the connected application using unsolicited result code +CMTI:

<mem>,<index>
<bm>:
0: No CBM indications are routed to the connected application.
<ds>:
0: No SMS-STATUS-REPORTs are routed to the connected application.
<bfr>:
0: The buffered notifications are sent.

Notice

-

46 Fehler! Verweisquelle konnte nicht gefunden werden.

MODEM MD720 in Terminal Mode

AT+CREG

Network registration

Test

Command:

AT+CREG=?

Response:

+CREG: (list of supported <n>s)
OK

Read command

Command:

AT+CREG?

Response:

+CREG: <n>,<stat>[,<lac>,<ci>]
OK

Executive command

Command:

AT+CREG=<n>,<stat>

Response:

OK

Parameter:

<n>:
0: disable network registration unsolicited result code
1: enable network registration unsolicited result code +CREG: <stat>
2: enable network registration and location information unsolicited result code

+CREG: <stat>[,<lac>,<ci>]
<stat>:
0: not registered, ME is not currently searching a new operator to register to
1: registered, home network
2: not registered, but ME is currently searching a new operator to register to
3: registration denied
4: unknown
5: registered, roaming

<lac>:
string type; two byte location area code in hexadecimal format (e.g. "00C3" equals 195 in

decimal)

<ci>:
string type; two byte cell ID in hexadecimal format

Notice:

Executive command controls the presentation of an unsolicited result code +CREG:
<stat> when <n>=1 and there is a change in the device network registration status, or
code +CREG: <stat>[,<lac>,<ci>] when <n>=2 and there is a change of the network cell.

Fehler! Verweisquelle konnte nicht gefunden werden. 47

MODEM MD720 in Terminal Mode

AT+CSCA

SMS service center address

Test

Command:

AT+CSCA=?

Response:

OK

Read command

Command:

AT+CSCA?

Response:

+CSCA: <sca>,<tosca>
OK

Executive command

Command:

AT+CSCA=<sca>[,<tosca>]

Response:

OK

Parameter:

<sca>
“Phone number SMS-ServiceCenters”
<tosca>
129, 145

Notice:

Executive command updates the SMSC address, through which mobile originated SMS
are transmitted. In text mode, settings are used by send and write commands. In PDU
mode, setting is used by the same commands, but only when the length of the SMSC
address coded into <pdu> parameter equals zero.

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MODEM MD720 in Terminal Mode

AT+CSMP

Set SMS text mode parameters

Test

Command:

AT+CSMP=?

Response:

+CSMP: (list of <fo>),(list of <vp>),(list of <pid>),(list of <dcs>)
OK

Read command

Command:

AT+CSMP?

Response:

+CSMP: <fo>,<vp>,<pid>,<dcs>
OK

Executive command

Command:

AT+CSMP=[<fo>[,<vp>[,<pid>[,<dcs>]]]]

Response:

OK

Parameter:

<fo>
17
<vp>
Determines the period of time the SMS will be stored in the SMS Service Center:
0 to 143: (<vp> + 1) * 5 minutes (e.g. 5 minutes interval up to 12 hours)
144 to 167 12 hours + (<vp> - 143) x 30 minutes
168 to 196 (<vp> - 166) x 1 day
197 to 255 (<vp> - 192) x 1 week
<pid>
0
<dcs>
0

Notice:

Until firmware version 1.6 inclusive, only the <vp> values 71, 167, 173 and 255 have
been supported.

In the composite AT command AT+CMGF=1+CSMP=17,0,0,0+CSCA="
+AAAAAAAAAAA" the value 0 for <vp> will be accepted, but 0 will be replaced by the
value 71.

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MODEM MD720 in Terminal Mode

AT+CRC

Set Cellular Result Codes for incoming call indication

Test

Command:

AT+CRC=?

Response:

+CRC: (list of supported <mode>)
OK

Read command

Command:

AT+CRC?

Response:

+CRC:<mode>
OK

Executive command

Command:

AT+CRC=[<mode>]

Response:

OK

Parameter:

<mode>:
0: disable extended format
1: enable extended format

Notice:

When enabled, an incoming call is indicated with

+CRING: <type> with, <type> : FAX or VOICE

AT+IPR

Set fixed local rate

Test

Command:

AT+IPR=?

Response:

+IPR: (list of supported auto-detectable <rate>s), (list of supported fixed-only
<rate>s)

Read command

Command:

AT+IPR?

Response:

+IPR: <rate> OK

Executive command

Command:

AT+IPR=<rate>

Response:

OK

Parameter:

<rate> bit rate per second
1200
2400
4800
9600
19200
38400
57600

Notice:

-

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MODEM MD720 in Terminal Mode

AT+KHNDVR

Selecting mobile / stationary operation

Read command

Command:

+ KHNDVR?

Response:

+ KHNDVR <stat>

Executive command

Command:

+ KHNDVR<stat>

Response:

OK

Parameter:

<stat>:
0: Setting for data calls (CSD 9600 Bit/s) in mobile operation
1: Setting for data calls (CSD 9600 Bit/s) in stationary operation

Notice:

The command has no impact to GPRS connections or the sending of SMS. In mobile
operation <stat> must be set to zero.

Composed AT commands

The initialization strings below are accepted by the MODEM MD720. The reaction
to the separate commands correspondingly.

TIM device

ATE0S0=1&D2+CBST=71,0,1;+CRC=1;&W+IPR=19200

S7-2xx-device

ATE0S0=0+IPR=9600

Other initialization strings

AT+CMGF=1+CSMP=17,0,0,0+CSCA="+AAAAAAAAAAA"
AT+CMGS="+BBBBBBBBBB",145

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MODEM MD720 in Terminal Mode

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5

Notice

You can find details about these functions in the system manual of the OPC server
SINAUT MICRO SC.

GPRS modem

In the OPC Mode the MODEM MD720 is configured by program building blocks of
the connected S7-200 PLC. The MODEM MD720 establishes autonomous the
radio data connection via GPRS between the connected S7-200 device and the
OPC server SINAUT MICRO SC.

SMS-Adapter

In addition also in OPC Mode the connected S7-200 device can send messages by
SMS:

● directly to other subscribers of the SMS service, or

● through gateways to fax machines.

To send a SMS, the GPRS connection to the OPC server SINAUT MICRO SC will
be interrupted.

GSM-Modem

Also the MODEM MD720 in OPC Mode can answer service data calls from analog
modems, ISDN modems or GSM modems.

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MODEM MD720 in OPC Mode

5.1 OPC Mode activation

Terminal mode is factory default setting

The MODEM MD720 supports two fundamental operating modes:

● Terminal mode

● OPC Mode.

The MODEM MD720 will be delivered by the factory with activated Terminal Mode.

Automatic activation by the PLC

Operating the MODEM MD720 in OPC Mode combined with S7-200 devices, the
OPC Mode will be activated by the program building blocks automatically during
the initialization.

Manual activation

If in exceptional cases a manual activation of the OPC Mode is necessary, you will
find instructions in chapter 6.1 Switching between Terminal mode and OPC Mode.

5.2 Operating requirements in OPC Mode: GPRS subscriber
contract

To use the MODEM MD720 in OPC Mode it is required:

 SIM card of a GSM network operator with activated GPRS,
 SIM card of a GSM network operator including CSD data service 9600 Bit/s

and an extra telephone number for data calls (to make Teleservice),

Availability of a GSM network

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5.3 Functions of the LEDs in OPC Mode

LED

Status

Meaning

S, Q, C
combined

Fast lighting in sequence

Boot procedure

Synchronous slow blinking

Service mode

Slow lighting in sequence

Update

Synchronous fast blinking

Error

S (Status)

Blinks slowly

Device waiting for PIN input

Blinks fast

PIN error / SIM error

OFF

No GPRS attach

ON

GPRS attach

Q (Quality)

Blinks slowly

Booking into GSM network

1x intermittent blinking

Field strength not sufficient

2x intermittent blinking

Field strength sufficient

3x intermittent blinking

Field strength medium

ON permanently

Field strength high

OFF

Waiting for PIN input

C (Connect)

OFF

No connection to MICRO SC

Blinks slowly

Trying to connect MICRO SC

ON

Connected to MICRO SC

Blinks synchronously to
data stream

Data transfer

The device is equipped with 3 LEDs which indicate the status:
S (Status) Q (Quality) C (Connect)

MODEM MD720 in OPC Mode

Blinks slowly: 1 time each second
Blinks fast : 4 times each second

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MODEM MD720 in OPC Mode

SIMSTATE=SIM_OK

Ready for operation

SIMSTATE=SIM_ERROR

Wrong PIN; one wrong PIN entry

SIMSTATE=SIM_PROBLEM

Wrong PIN; two wrong PIN entries or no SIM
detected

5.4 PIN in OPC-Mode

Enter the PIN

If the LED “S” blinks slowly (1 time per second), the MODEM MD720 waits for a
PIN entry.

In OPC-Mode the PIN is sent by the connected PLC to the MODEM MD720.
Therefore you need to enter the PIN in the data module of your SPS program with
reference to the program module WDC_INIT (See System manual SINAUT MICRO
SC). Please check if the PLC and the MODEM MD720 are connected together.

The LED S (Status) blinks fast

If the LED S blinks fast (4 times per second), either the SIM card was not detected
or he SIM card is PUK-blocked, because a wrong PIN has been entered too often.

1. Please check, if the SIM card has been inserted correctly into the device (refer
to chapter 2 Inserting the SIM card).

2. Please check, if the SIM card is PUK-blocked. Insert the SIM card into a
common mobile phone. The mobile phone will display, if the SIM card is PUK­blocked. If the SIM card is PUK-blocked, please enter the PUK and then a PIN.
You can use a common mobile phone to do this.

3. Before you enter again the SIM card into the MODEM MD720, please
investigate why the SIM card has been PUK-blocked: Which PIN have you
entered into your PLC program?

4. Please check and eventually reset the parameter SIMSTATE of the MODEM
MD720.

Check and reset the parameter SIMSTATE

The parameter SIMSTATE will be displayed when you press the SET button (refer
to 6.2 Getting the current settings and values):

In case of SIMSTATE=SIM_ERROR or SIMSTATE=SIM_PROBLEM please
proceed as follows:

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MODEM MD720 in OPC Mode

1. Please make sure, that the correct PIN is entered into the PLC program
module.

2. Push the SET button until the factory default settings has been loaded
(Attention, all settings will be reset)

or
Enter the following AT commands:
AT^PARSTART

AT^PARCSE
AT^PAREND

3. Afterwards the device will perform a restart and is ready of operation again.

Changing the SIM card

If you change the SIM card, please do not forget to update also the PIN number in
your application.

If you use a lot of SIM cards it can be helpful to set all PINs to the same PIN
number. You can do this i.e. by using a mobile phone. Please observe the security
requirements of your organization.

PIN-less SIM cards

The device operates also with SIM cards, which PIN check is deactivated. In this
case the PIN check is skipped and the device will immediately try to attach the
GSM network.

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MODEM MD720 in OPC Mode

After switching on:

3 trials in succession

After about 2 minutes of waiting:

3 trials in succession

After about 4 minutes of waiting:

3 trials in succession

After about 6 minutes of waiting:

3 trials in succession

After about 10 minutes of waiting:

3 trials in succession

After about 15 minutes of waiting:

3 trials in succession

Always after each 15 minutes:

3 trials in succession

5.5 Log in to SINAUT MICRO SC

After the SINAUT MG720-3 is switched on and configured by the control or after a
connection is broken off the MODEM MD720 starts at once to connect itself with
the OPC Server SIANAUT MICRO SC, if the MODEM MD720 is in OPC mode.

If the trial of the MODEM MD720 to connect with the OPC Server SIANAUT
MICRO SC does not succeed it will start another trial according to the following
scheme:

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6

6.1 Switching between Terminal mode and OPC Mode

The MODEM MD720 is delivered by the factory with activated Terminal Mode.
Operated in combination with a S7-200 the OPC Mode of the MODEM MD720 will

be activated by program building blocks of the connected S7-200 PLC during the
initialization.

Manual switching

There are the following two methods to switch the MODEM MD720 manually from
the Terminal Mode into the OPC Mode and vice versa.

Change the operating mode by AT commands. Enter therefore the following
commands:

+++

Activates the AT command interface and interrupts the data transfer.

AT^PARSTART<CR>

Activates the AT configuration

AT^PARSET=”TERMINAL”,”MODE”,”SUPERVISED” <CR>

Selects the Terminal Mode, or

AT^PARSET=”TERMINAL”,”MODE”,” DISABLE ”<CR>

Selects the OPC Mode.

AT^PAREND<CR>

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Service functions

The device restarts in the selected new operating mode.

Deactivates the AT configuration and forces a restart of the MODEM

MD720.

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6.2 Getting the current settings and values

Connect your PC to the interface X1 and start a terminal software, e.g.
HyperTerminal. Select the used COM interface of the PC and configure the
character format and the baudrate to the same settings as the X1 interface of the
MODEM MD720.

By factory default the MODEM MD720 has the following settings:
Baudrate 9600 Bit/s (in OPC Mode) or

19200 Bit/s (in Terminal Mode)
Character format 8N1
When you push the SET button (less than 2 seconds) the correct IP configuration

of the MODEM MD720 is shown by the terminal software.

Assigned-IP: Assigned IP address (OPC Mode)
Remote-Host:217.6.61.22 IP address of the OPC servers (OPC Mode)
Destination-Port:20030 Port address of the OPC server (OPC Mode)
Source-Port:26863 Own port address (OPC Mode)
Remote-Host2: Reserved
Destination-Port2:26862 Reserved
Source-Port2:RANDOM Reserved
Server-Mode:TSC Reserved
Server-Line:LL Reserved
Server-Username:st User name at the OPC server (OPC Mode)
Server-Username2:G21 Reserved
Dial-Up:GPRS Reserved
System-Time:1894 System time since last restart
Terminal-Mode:DISABLE Active mode: Terminal mode or OPC Mode
Firmware-Version:V.1.2.0 Firmware-Version
SIM-STATUS:SIM-OK SIM/PIN-Status
Provider: GSM-Operator
NetID: ID of the GSM-Operator
APN: APN of the GPRS network
Quality:99 Receive quality (CSQ- value)
COM-Control:DTR Reserved
COM-Baudrate:9600 Baudrate on X1 interface
COM-Format:8E1 Character format on X1 interface

Service functions

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Service functions

6.3 Load factory defaults

By pushing the SET button for more than 4 seconds till the LED “C” begins to light
up, the configuration of the MODEM MD720 will be reset to factory default
settings.

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7

Interface X1

Function

GPRS connections to SINAUT MICRO SC
GSM data calls (CSD 9.600 bps) MTC
SMS sending

Standard

RS232 (V.24 / V.28), plug: D-SUB 9 pins

Default speed

9600 bps

Control

AT commands

Air interface

GSM module

GPRS / CSD / Quad band

GPRS

Up to 2 uplinks / up to 4 downlinks (max. 5 Slots)

Transmit power

GSM 850 MHz (max. 2W), GSM 900 MHz (max. 2W),
DCS 1800 MHz (max. 1W), PCS 1900 MHz (max. 1W)

Antenna connector

SMA / 50 Ohm

Power supply

power consumption

typ. 5.5W

Supply voltage

12 - 30 VDC (24 VDC nominal)

Supply current /
Established GPRS
connection with
data exchange

1000

200

400

600

800

1200

1400

[mA]

[ms]

10 20 30 40 50 7060 80 90 100

I

Burst

at 12V

1000

200

400

600

800

1200

1400

[mA]

[ms]

10 20 30 40 50 7060 80 90 100

I

Burst

at 24V

12 V: In = 265 mA, IBurst = 1,3 A
24 V: In = 109 mA, IBurst = 0,8 A

4,62ms Burst repetition rate

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Technical Data

Supply current / no
connection or
connection to
SINAUT MICRO
SC without data
exchange

In 90mA at 12V
In 50mA at 24V
In 40mA at 30V

Ambient
conditions

Temperature range

Operation: –20°C up to +60°C
Storage: –25°C up to +85°C

Humidity

0-95 %, not condensing

Mechanics

Construction

Top-hat rail housing

Material

Synthetic material

Protection category

IP30

Dimensions

30 x 100 x 90 mm

Weight

Approx. 150g

Approvals

CE

Yes

R&TTE

EN 301 511; EN 301 489-1 / -7

EMV / ESD

EN 55024, EN 55022 Class B, EN 61131-2

ATEX

III 3 G EEx nA II T4 Ta=-20°C-60°C

FM

CLI, DIV2, GP. A,B,C,D T4 Ta=-20°C-60°C
CLI, Zone 2 IIC, T4 Ta=-20°C-60°C

UL

E301826

Signals
(Signal direction DTE)

SUB-D9 socket, Pin assignment
RS232

Pin1

DCD

Output

Pin2

RXD

Output

Pin3

TXD

Input

Pin4

DTR

Input

Pin5

GND

Signal ground

Pin6

DSR

Output

Pin7

RTS

Input

Pin8

CTS

Output

Pin9

RI

Output

Interface X1

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to Modem
DSUB
9-pin
connector

to PC
DSUB
9-pin
plug

Modem cable for Service Interface

Technical Data

The line RI is an option.

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Technical Data

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Glossary

GSM
Global System for

Mobile

Communication

Global standard for wireless telephony, data and fax transmission and
transmission of text messages (SMS). GSM based networks are
available in a lot of countries world-wide, with high coverage in Europe,
China, Latin America as well as in regions of the USA, Africa and
Russia. Depending on the used frequencies you distinguish PCS
850MHz, GSM 900MHz, DCS 1800MHz und PCS 1900MHz networks.

CSD
Circuit Switched Data

GSM Service for wireless data transmission at 9600 bps full duplex.
Connections can be established to other GSM devices, to analogue
modems or to ISDN modems in wired networks. The connections can
be initialized at both sides. Only dial-up connections are supported.

GPRS
General Packet Radio

Service

GSM service for IP-based data transmission. Over GPRS network
connections are established, either to the internet or to private
networks.. Data are transmitted using the internet protocols TCP/IP or
UDP/IP.

OPC

OPC covers a series of specification for data exchange in automation
technologies between control devices, sensors etc. and control systems
(see www.opcfoundation.org).

Protocol, transmission
protocol

Devices which communicate with one another must use the same rules
for this communication. They must "speak the same language". Such
rules and standards are collectively referred to as a protocol or
transmission protocol. Often used protocols are, for example, TCP/IP
and PPP.

COM-Port

The term "COM port" (communications port) is used to describe a serial
interface (RS232) on a Windows PC. Application programs use COM
ports for data transmission to various devices such as modems, PCs,
terminals etc.

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