GSM tELEpHonIC IntERfaCE
The IT MINI interface simulates a traditional telephone line (PSTN) using a GSM system module.
It can be used as telephone backup system when a PSTN line is out of order or is not available: in these
conditions, or if the interface is properly configured, a call from an external unit is forwarded through the
The system is completely transparent to SIA FSK and CONTACT ID protocols signals; it also provides a
signalling PSTN Fail relay output (NC/NO).
Using SMS commands IT MINI can be remotely configured and can generate system informations.
aUtoMatIC SMS MESSaGES
IT MINI handles incoming and outgoing SMS messages. Incoming messages are used to configure the
system. Outgoing messages can be answers to commands or the following event-generated (if enabled)
ID Default text1 Description
1 LIfE tESt programmable life test: sent periodically according to the configu-
3 GSM no LInE GSM fail: this message is sent as soon as the GSM network becomes
available after a programmable out of service time
4 pStn faILURE pStn line faIL: if the PSTN line is not available this message must
5 “Sender ID”:received SMS echo function: this function forwards each incoming not reco-
text2 gnized SMS (e.g.: SIM card expiry, credit exhaustion, etc.)
6 GSM:ok LEV :3 After detecting a ring from the GSM network, the system checks if the
pStn:faIL calling telephone number belongs to the address book and, if yes, it
answers with a message containing the system status.
This message doesn’t need to be associated to a specific telephone
number of the address book.
1) The text of the first 3 messages can be changed
2) The echo function returns the message received by the system preceeded by the sender id.
This function also allows to monitor improper access attempts
A SMS message is sent if the relevant event occurs and if it has been previously associated at least to a
telephone number (8 telephone numbers may be stored in the system): by default, all messages are asso-
ciated to the first telephone number of the address book.
boaRD LaYoUt, tERMInaLS anD ConnECtIonS
attention: introduce a SiM card with no data
stored in its memory (no telephone numbers in
address book and no text messages).
the SiM card insertion and extraction operations
must be done with the interface completely devoid
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SuppLY +- 13.8Vdc power supply
GSM In CoM When terminal “In” is closed to terminal “CoM”, all outgoing calls are
force forwarded to the GSM network even if the pStn line is available.
Remark: in this case, an incoming call from the pStn line will not be received and the
system will result in the free condition but will not generate any ring to the connected
LInE L1 L2 Connections to the pStn line
pHonE t1 t2 pStn simulated line terminals to connect to the alarm system
pStn FaiL Relay output active when the pStn line is not available
KeY SW1 parameters ReSet key
The following 3 LEDs provide systems status informations:
YeLLoW This LED gives the GSM link status: after startup this LED blinks to indicate that the system
is trying to login the GSM network.
GSM Once logged the LED is turned OFF if the PSTN line is available and is turned to a steady
STATUS ON status is the PSTN line is not available.
When the system is working on the GSM network (outgoing call or SMS or incoming SMS)
the LED blinks.
GREEn This LED indicates the GSM signal strength. At system startup it blinks together with the yel-
low LED then it blinks according to the GSM signal strength:
GSM 1 blink and 1 pause: signal absent or too weak (if this condition is stable it is
SIGNAL reccomended not to use this system)
LEVEL 2 blinks and 1 pause: sufficient signal
3 blinks and 1 pause: good signal
RED This LED blinks when a system failure occurs (GSM out of order or network not available,
SIM card locked). If the problem is related to GSM network the RED and the YELLOW LEDs
SYSTEM will blink simultaneously.
RESEt (DEfaULt) bUtton
To return to the initial default programming condition the system must be turned off (disconnecting supply)
and then turned on with the RESET KEY (SW1) pressed.
The are two type of system reset:
1° paSSWoRD RESEt: if the key is pressed for about 5 seconds only the system password is reset
2° totaL RESEt: if the reset key is pressed for more than 10 seconds the system will resume the default
REMaRk: during reset the RED LED is turned on, the GREEn LED blinks and, only for totaL RESEt, the YELLoW LED
gives a short flash.
3 IT MINI
SIM CaRD anD pIn CoDE
The system normally works with SIM cards without the PIN code. If the SIM card cannot work without the
PIN code it must programmed to the 1234 value: the board will use that code to use the SIM card.
In case of SIM card provided with PIN code, it’s possible to set in the SIM card the code 1234. This code is
used by the system for the release of the SIM card.
USE of tHE IntERfaCE WItH a tELEpHonE ExCHanGE SYStEM
When the IT MINI is connected to a telephone exchange, the number generated by the alarm system may
contain a prefix that must be skipped when forwarded to the GSM network (eg: the 0 065487954 number
must exit as 065487954).
This can be done through a suitable system setup (see the relevant paragraph).
ex: the 0 065487954 becomes 065487954
IT MINI is able to generate either a continuous dial tone (default setting) or a pulsed dial tone.
To change the setting a suitable SMS command must be sent (PULSE=on/off).
At system reset, all SMS messages are associated to the first telephone number (if any): to modify
this setting it is necessary to send a suitable command to the unit (smstel.x=0)
at system reset, all SMS messages are associated to the first telephone
number (if any): to modify this setting an suitable command must be sent
to the unit
pRoGRaMMInG anD ManaGEMEnt WItH SMS tExt MESSaGES
use of the sms text messages for remote programming
As already explained, IT MINI is completely configurable by means of SMS text messages.
To program the system, the user must send a text message suitably formatted.
A command can be composed by more fields separated by a space character: each field is composed by a
command id, an optional command index, an operator and a value (ID[.index]operator[value])
The first field of a command text must be the password declaration in order to authenticate the user access
(e.g.; pWD:000000) .
The following operators are recognized by the system:
operator name Example
: Declarator PWD:111111 This statement declares the password value
= assignment TEL.3=1234 This statement assignes the 123456 value to the third phone
? Request PFX? This statement asks the system to return the PFX parameter
After receiving a SMS, the system will execute the command(s) and will answer with a SMS containing the
result of each single command.
For example, after receiving the “PWD:000000 TEL1.1=24 “ SMS, the “PWD:OK TEL.1:OK” SMS will be
A wrong field will be answered with the *FAIL* indication while a not recognized field will be answered with
the *?* indication.
Commands are CASE UNSENSITIVE and may be written either in capital letters or in small letters.
WaRninG: incoming messages exceeding 64 characters will be ignored and will be not acknowledged.
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sms text commands
CoMManD DESCRIptIon ExaMpLE
Password declaration or assignment pwd:000000 this command allows the user to
The number of characters of the password login the system
ranges from 0 to 6; if 0, the password is do- pwd=111111 this command sets a new password
pWD sabled but an empty password declaration
command must be used to access the sy-
Command to assign a value (max 32 cha- tel.1=+39339258741
racters) to one of the 8 telephone numbers
tEL provided by the system. The command must
be followed by an index. The admitted cha-
racters are numbers and ‘+’
Command to assign a text value (max 40 smstext.1=periodic_life_test
characters) to one of the 4 SMSs supported This command will substitute the default value of
SMStExt by the system (the 5th and the 6th cannot be the life test SMS with the “periodic_life_test” text.
configured). Warning: if the text contains space characters, it
The command must be followed by an index. must be included in a “ pair
Command to link a SMS message to one or smstel.1=12 smstel.3=4 smstel.4=0
more telephone numbers. SMS 1 will be sent to telephone numbers 1 and 2;
SMStEL The command must be followed by an index and SMS 3 will be sent to telephone number 4
list. and SMS 4 will not be sent to any number
Command to define the lifetest output signal lfout=5
LfoUt duration in second units The lifetest output will be active for 5 seconds
Command to define the time duration of the lftime=10
lifetest time in minute units: during lifetest
LftIME SMS dispatch, for the specified time, the sy- Sets the lifetest time to 10 minutes.
stem will switch to the GSM network even if
the PSTN line is available.
Command to set the lifetest interval in hour lfdelay=24
LfDELaY units . Lifetest (signal activation and SMS dispatch) will
be executed every 24 hours.
Command to set the delay, in hour units, lfstart=8
between the current SMS reception time and The firtst lifetest procedure will start after 8 hours.
the first execution of lifetest operations. For example, with this command is possible, at
LfStaRt 17:00, to program procedure to be executed at
01:00 time. Starting at 01:00 the lifetest will be
executed every LFDELAY value hours
This command sets the GSM signal absence gsmoff=5
time threshold (in minute units) to trigger the If the GSM network is not available for more than
GSMoff GSM FAIL SMS forward operation. 5 minutes, the system wiill send, as soon as pos-
sible, the GSM FAIL message.
This command forces or not the usage of the gsm=on the system will work only on the GSM
GSM network. network line ignoring the PSTN line
gsm=off the system will use the PSTN line if
(on|off) available, otherwise it will use the GSM
Command to add a prefix (max 6 characters) pfx=+39
to the telephone number of an GSM network The prefix +39 will be added to the telephone num-
outgoing call . ber generated by the alarm unit.
pfx For example, if the units generates 335349872
number, when forwarded to the GSM network the
+39335349872 number will be composed
This command enables or disables the tele- skip=on the first digit of the number generated
SkIp phone extension option. by the alarm unit will be skipped when
(on|off) operating on the GSW network
skip=off no digit will be skipped
pULSE This command configures the output dial pulse=off the unit generates a continuous dial
(on/off) tone (ON=pulsed OFF=continuous) tone
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parameter Default value Min Value Max Value Units
paSSWoRD 000000 from 0 to 6 characters
LfoUt 5 0 100 seconds
LftIME 0 0 30 minutes
LfDELaY 0 (disabled) 0 240 hours
LfStaRt 0 (immediate dispatch) 0 240 hours
GSMoff 5 0 240 minutes
GSM off (pStn line used) off/on
pfx Empty (no prefix) 6 characters max
SkIp off (no digits are skipped) off/on
pULSE off (continuous dial tone) off/on
Command answer notes
pWD:000000 pWD=123456 pWD:ok assigns a new value to the pas-
pWD:000000 tEL.1=+39338790911 pWD:ok assigns the given value to the first
tEL.1:ok telephone number
pWD:000000 tEL.1? pWD:ok Returns the requested telephone
pWD:000000 tEL.2=33902537 pWD:ok
lfdelay=24 lfstart=3 smstel.1=1 tEL.2:ok
pWD:000003 tEL.2=33902537 pWD:*faIL* Incorrect password
lfdelay=24 lfstart=3 smstel.1=2
pWD:000000 tL.9=33902537 pWD:ok
lfdelay=24 lfstart=3 smstel.1=2 tL.9:*?* Command not recognized
pWD:000000 smstext.1=my_life_ pWD:ok
pWD:000000 smstext.1=my life pWD:ok because of the presence spaces in
test SMStExt.1:ok the text, only the “my” text will be
life*?* accepted; “life” and “test” words will
test*?* be intepreted as commands and will
be not recognized
pWD:000000 smstext.1=”my life pWD:ok because of the “ markers, the space
test” SMStExt.1:ok characters have been accepted
pWD:000000 smstel.1=0 pWD:ok Clear all association among address
smstel.2=0 smstel.3=0 SMStEL.1:ok book and SMS messages
smstel.4=0 smstel.5=0 SMStEL.2:ok
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IMQ level TO BE DEFINED
Power supply 13.8 Vdc nominal (min: 9Vdc, Max: 14.5Vdc)
Nominal current 110 mA
Maximum current 300 mA (peak 320 mA)
Emulated line tone 440 Hz
Emulated line voltage 12 Vdc
Size 103 x 57 x 18,5 mm
Temperature range From +5°C to +40°C
Meets the requirements:
en50131-1 Grade 2
environmental Class 2
Installation must be carried out following the local installation norms by qualified personnel.
The factory refuses any responsibility when changes or unauthorized repairs are made to the product/sys-
tem. It is recommended to test the operation of the alarm product/system at least once a month. Despite
frequent testing and due to, but not limited to, any or all of the following: tampering, electrical or com-
munication disruption or improper use, it is possible for the product/system to fail to prevent burglary,
robbery, fire or otherwise. A properly installed and maintained alarm system can only reduce the risk that
Any GSM speech dialler or communicator, not connected to the PSTN standard telephone line, does not
ensure proper communication in case of problems or limitations due to the GSM network.
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