Black Box Industrial Control MDU20G-918 User manual

Industrial Control Modem GSM
Quick Start Guide
TECHNICAL:
SALES:
FAX:
ADDRESS:
WEB:
[phone]
[phone]
[phone]
464 Basingstoke Road, Reading, Berkshire RG2 0QN
www.blackbox.co.uk
Industrial Control Modem GSM 900/1800MHz:
MDU20G-918
Magnetic Aerial:
MDU21-MAG
Roofmount Antenna:
MDU21-ROOF
Standard Antenna:
MDU21-STD

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Industrial Control Modem GSM
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How To Contact your Local Black Box
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Black Box Italia S.P.A Black Box Catalog Australia PTY LTD
Tel: [phone] Tel: [phone]
Fax: [phone] Fax: [phone]
Web Site: www.blackbox.it
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Black Box Deutschland Black Box Do Brasil.
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Black Box Black Box Catalog
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Industrial Control Modem GSM
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France: U.S.A
Black Box Catalogue Black Box Corporation
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Fax: [phone] Fax: [phone]
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Web Site: www.blackbox.es Web Site: www.Blackbox.cl

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Industrial Control Modem GSM
SALES: 0118 965 5100
Contents
Introduction..............................................................................................................................................5
Package Contents......................................................................................................................5
GSM Network Connection.......................................................................................................................6
Configuration...........................................................................................................................................7
Test Commands.......................................................................................................................11
Informative Commands.............................................................................................................11

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Industrial Control Modem GSM
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Introduction
Congratulations on purchasing one of the best GSM Data Terminals available today. The
Industrial Control Modem GSM will provide reliable service, provided it is connected to an
appropriate GSM Network and configured correctly. This booklet will guide you through
these stages.
Package Contents
Packed in with the GSM Data Terminal you will find a diskette, this contains three files, this
booklet, the User Guide and a manual of AT Commands, all in PDF format.

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Industrial Control Modem GSM
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GSM Network Connection
It is up to you to choose which GSM Network you would like to use, but please be aware that
there are three different frequencies used for GSM communications, 900, 1800 and 1900
Mhz. For instance in the UK, Vodaphone and Cellnet use 900Mhz and One to One and
Orange use 1800Mhz. You should order your data terminal to match the Network you plan
to use. A list of GSM Networks and their frequencies is available on page 118 of the AT
Commands manual, but please check with your Network Provider to confirm that no changes
have been made.
When opening your GSM account please ask your Network Provider for a Data Account.
Data Accounts usually have a much lower monthly charge than Audio Accounts.
Regardless of the type of account you have, Data or Audio, you must ensure that the SIM
card you receive is DATA ENABLED. Even if you have a Data Account, please check to
confirm that it has been Data Enabled, sometimes this is not done automatically.
You will normally receive three telephone numbers will each account, one for Audio
(probably won’t work on a Data Account), one for Fax and one for Data. Obviously the Data
number is the one to use. If you do not have a separate Data number please confirm with
your Network Provider that the number you have is a Data number. The reason for this
additional numbering is that not all the analogue fixed-line exchanges/switches can process
and route the digital data that the digitally-based GSM networks use. Thus the digital data
must be fed through an appropriate incoming voice, data, or fax number.
Once you are satisfied that you have an Enabled Data Account, please check that the SIM
card PIN number is not enabled. To do this place the SIM card in a normal GSM phone and
check that the need to insert the PIN number, when the power is switched on, is disabled.
You may now place the SIM card in your Industrial Control Modem GSM, power it up and
check the Network connection (refer to Users Manual). On power up the LED on the front
of the unit will be lit steady, this means power is on, but no Network Connection is available.
After a short period of time the LED will start to flash, short time lit and longer time dark,
this means a Network Connection is established.

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Industrial Control Modem GSM
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Configuration
As with other types of modem the Industrial Control Modem GSM has many different
configurations available, possibly only one of which will be suitable for your application.
The factory default configuration is a general-purpose type, which will work with many
different types of equipment, but you may need to adjust some settings. In most cases only a
few changes may be necessary and the most common are outlined below:
You should be aware of two terms, which are used extensively in Data Communications,
DTE (Data Terminal Equipment) and DCE (Data Communications Equipment).
PCs, industrial controllers and telemetry outstations are normally DTEs and modems are
normally DCEs.
The Industrial Control Modem GSM is a DCE and the device to which you connect it will
almost certainly be a DTE.
In the text below the Industrial Control Modem GSM will now be referred to as the DCE and
your Connected Equipment as the DTE.
AT Commands
The Industrial Control Modem GSM (DCE) is Hayes compatible, meaning that it uses Hayes
type AT commands. For setting up the configuration, these commands can either be loaded
into its internal memory or can be given to the unit, by its connected equipment (DTE), in the
form of an initialisation string.
AT commands always start with “AT”and several commands can be given in one command
string, provided the string does not exceed 40 characters. For instance the default
initialisation string used in a RTU8 Telemetry Outstation is AT&C1E0V0S0=1. A full
explanation of these parameters is given in the AT Commands manual, but the most
commonly used, and therefore the most likely you will have to adjust are:
Command Explanation
ATVn Result codes in numerical or verbose form.
V0 numerical, 0,1, etc.
V1 verbose, OK, ERROR, etc.
Check which type of result code your DTE requires.
AT&Cn Carrier Detect
&C0 DCD is always active
&C1 DCD is active if modem is on line
Data Carrier Detect (DCD) is a hardware signal that notifies the DTE that the DCE is in
communication with another modem. Some software will not start-up properly if the DCD is
active. Default is &C1.

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Industrial Control Modem GSM
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AT&Dn Data Terminal Ready settings
&D0 Modem ignores DTR
&D1 Modem switches from data to command mode
when DTR switches from ON to OFF
&D2 Upon DTR switch from ON to OFF, the call is
cleared down
AT+IFC Defines if Flow Control is used between DTE and DCE.
+IFC=0,0 No flow control
+IFC=2,2 RTS flow control (preferred)
Flow control is the use of RS232 signals to start and stop the flow of data to avoid data loss
during buffering. Check if your DTE supports RTS/CTS flow control (Hardware flow
control). With Flow Control the DTE will send data to the DCE. The DCE will store this
data in a buffer. When this buffer is full, the DCE will drop the CTS-line, telling the DTE
that it has to stop transmitting data until the signal raises again. If the RTS-signal is OFF,
transmitting data to the DTE is stopped until the signal switches to ON.
AT+IPR Defines the Baud rate used for communications between the DTE and DCE.
AT+IPR=0 The Baud rate is selected automatically
AT+IPR=9600 The Baud rate is fixed at 9600 baud or another speed.
This is best left at its default setting of 0 (auto), unless your DTE demands
otherwise.
AT+CBST Defines the type of Bearer to be used. That is the communication between
the DCE and the GSM Network.
AT+CBST=0,0,0 Auto baud rate selection, transparent mode
AT+CBST=0,0,1 Auto baud rate selection, non-transparent mode
AT+CBST=7,0,0 9600 (V32) baud rate selected, transparent mode
AT+CBST=4,0,1 2400 (V24bis) baud rate selected, non-transparent mode
Usually the baud rate is best left in the default Auto selection. Non-transparent copes with
bad connections better than transparent mode, but transparent mode will pass data more
quickly. Try either to see which is best for your application.
Non-Transparent communication utilises a special GSM network-based error correction
facility called "Radio Link Protocol" (RLP) that ensures a more robust transmission. What
this essentially means is that the GSM network will add special error correction codes to
control the flow of data.
This ensures that the data transmitted first obtains a special acknowledgement signal from the
receiver that informs the transmitter that the data has been received as transmitted and that
the receiver is ready to receive the next set of data from the transmitter. If there is no such
acknowledgement signal from the receiver, the networks will utilise their "data buffering"
feature by using a special "forward correction" technique to ensure uninterrupted data
transmission throughout.

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Industrial Control Modem GSM
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With transparent data transmission GSM error correction is not applied, over the air interface.
AT+ICF This command is used to determine the local serial port start-stop
(asynchronous) character framing that the DCE shall use. If your
application requires something other than the normal 8 data bits, 1 stop
bit and no parity, you may use this command to make the change. See
AT Command manual
for full details.
ATEn Defines if the DCE echoes (sends back) characters to the DTE.
ATE0 Characters are not echoed
ATE1 Characters are echoed Check which your DTE requires
ATS0=n Defines whether the DCE should answer incoming calls automatically.
ATS0=0 Incoming calls not answered
ATS0=1 Incoming calls answered after 1 ring
ATS0=5 Incoming calls answered after 5 rings
The default is 0, therefore if incoming calls are to be answered this point must be changed.
Usually set to 1. Note - make sure you use a 0 (zero) after the S and not a letter O.
If your DTE will not work with the default configuration in the Industrial Control Modem
GSM, remembering that the ATS0 command must be changed if incoming calls are to be
answered, the above are the most likely parameters that may need changing. Experience
suggests that only one or two points may need to be changed. You will need information
from the manufacturer of your Connected Equipment (DTE) in order to configure the
Industrial Control Modem GSM (DCE) correctly. Ask for advice on each of the above
commands.
If you wish to give the DCE these commands via an initialisation string, from the DTE, either
on power up and/or when a call is to be made, then they may be made in the normal manner,
such as:
AT +IPR=0 +CBST=0,0,1 &C1 E0 V0 S0=1
Note. The spaces have been inserted for clarity and need not be placed in the string. Again
for clarity we suggest that upper case is used.
If you wish to store the configuration permanently in the Industrial Control Modem GSM
(DCE) then you may use a PC terminal programme, such as HyperTerminal (supplied with
Windows) as follows.
Start HyperTerminal, name the new connection and hit OK. In the next pop-up box go to
“Connect using”and select “Direct to Com1”, assuming you are using Com1. Hit OK.
On next pop-up box go to “Bits per second”and select 9600, leave all other parameters as
they are. Hit OK.

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You will now have a screen via which you can communicate with the DCE, BUT NOT
BEFORE YOU HAVE TURNED ON THE CAPS LOCK. Please make sure you do this.
Now type AT and return. The DCE will respond with OK.
If the DCE responds with a 0 or 1, enter ATV1 and return, you will then get an OK. (See
ATV command above)
If you can’t see what you type, carefully enter ATE1 and return. Text should then appear.
(See ATE command above)
You are now ready to talk to the DCE.
Configuration commands are simply entered thus:
ATS0=1 [return]
OK (response from DCE)
Each command can be entered in this way, making sure that the DCE responds with an OK
after each carriage return. OK means the command has been accepted. If the DCE responds
with “ERROR”, the command has not been accepted and you should re-enter it, carefully
checking your syntax.
Your screen could then look like:
When you have finished entering your configuration commands you need to store them in the
memory of the DCE. To do this enter:
AT&W
OK
You have now configured the DCE.
There are some other useful commands you can use to obtain information or test the DCE:
AT+CBST=0,0,1
OK
AT+IPR=0
OK
ATS0=1
OK

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Test Commands
ATDnnnn This causes the DCE to dial a number (nnnnnn)
ATH Hang up
ATA Answer an incoming call
Informative Commands
ATI Used to query DCE for its identifiers, such as frequency
AT+COPS? Will inform you as to which GSM Network you are connected. See page 118
of the AT Commands manual for a list.
AT+CSQ Will tell you the signal strength. 17 roughly equates to 4 bars on a hand
phone, 10 to about 2 bars, which should be sufficient for data transfer.
AT&V0 Will display the DCE current configuration
AT&F This command is used to restore the factory settings from EEPROM, this will
take you back to square one, regardless of any changes you have made.
These settings are listed in appendix 16.10. of the AT Commands Manual