Serial GSM Gateway User Manual
Copyright © 2009-2010 Smartsavy Limited. All rights reserved.
26
The GSM Functions Menu
The Serial GSM Gateway uses GSM technology to send and receive SMS messages, and to connect to the
Internet.
The Serial GSM Gateway is capable of using both account based SIM cards and prepaid SIM cards.
Account based SIM cards are those that a billing account is created by the mobile network operator and a
monthly bill is received by the customer for all activity during a monthly period. The services provided by the
mobile network operator are never interrupted due to lack of funds unless a bill has not been paid.
Smartsavy recommends the use of account based SIM cards.
The second type of GSM SIM card is a prepaid SIM card. The prepaid SIM card gets loaded with credit that is
used by the customer. As the mobile network operator services are used the credit gets depleted. Once the
credit is depleted all mobile network services that attract a cost are stopped until additional credit is loaded on
the prepay SIM card. If this type of SIM card is used in the Serial GSM Gateway, it is critical that the prepaid
credit is never fully depleted. Depleting the credit will cause the Serial GSM Gateway to function incorrectly,
and features such as SMS alerts and remote GPRS console access will be disabled.
The Serial GSM Gateway has two features that allow for the use of the prepaid SIM card.
1. Automatic balance checking by the Serial GSM Gateway. If the balance or credit of the prepaid SIM card
falls below a threshold configured by the customer, a SMS alert will be sent to the customer’s
configured mobile telephone alerting of the low balance situation.
2. Topup of prepaid balance or credit. The customer is able to purchase a topup voucher from the mobile
network operator. Using the topup voucher pin number, the customer can either send a specially
crafted SMS message to the Serial GSM Gateway or use the Serial GSM Gateway’s Menu to enter in the
topup voucher pin number. If successful the balance or credit of the prepaid SIM card will be updated
to the new balance or credit as purchased from the mobile network operator and the Serial GSM
Gateway will continue to function correctly.
The GSM SIM card and Serial GSM Gateway also holds information that is required by the mobile network
operator in certain circumstances. This information is accessed via the ―GSM functions menu.
The ―GSM functions‖ menu
(Figure 3-6)
is where you can perform prepaid actions, and view various settings
that may be required by your mobile network operator. The ―GSM functions‖ menu can only be accessed from
the ―Main‖ menu. It is option number ―4‖ on the ―Main‖ menu.
A full description of the ―GSM functions‖ menu options are in
(Table 5).
Follow these steps to get to the ―GSM functions‖ menu:
Note
Remember after you enter the number associated with a menu option, you must press
the ―Enter key‖.
