27
To switch off the modem, disable power voltage applied to it. Data transmission over GPRS will be terminat-
ed.
4.2. Device Operating Procedure
When enabled, the modem verifies power supply voltage. If it is less than the minimal allowed voltage, the
log will prompt an error message ("POWER ERROR"), and the modem will wait for power voltage sufficient to
operate.
After supplying voltage to the modem sufficient for operation, the SIM card is verified. If the SIM card re-
quests a PIN code, the modem is loaded using the PIN code specified in the settings. When the PIN code is
incorrect, the modem deletes it from the memory to prevent SIM card locking. If the PIN code is not specified in
the modem settings, but the SIM card requires it, the modem does not operate with this SIM card until the tray
is restarted.
After the SIM card's successful loading, the modem registers with the network and clears the memory of
SMS messages. The modem establishes GPRS connection and connects to the server (in the
Client
mode) /
opens the port for incoming client connections (in the
Server
mode).
When operating with the standard server (not iRZ Collector), the modem re-establishes connection with it if
there is no data transmission within the time interval (set by the
Connection Check Interval
setting). Default
time interval
– 10 minutes. Changing the interval as well as learning the current value is only possible via AT
commands.
When operating with the iRZ Collector specialized server, the modem sends a keepalive packet to the iRZ
Collector server to verify connection if data transmission is not available for over a minute. If there is no re-
sponse to the keepalive packets, the server clears the connection.
When the modem operates in the
Server
mode, test connection to the public servers is performed to verify
connection. For more details on the basic settings, refer to the
section.
If going online and connecting to the modem is impossible, the modem repeatedly retries connection at the
set time intervals (
Connection Retry Interval
setting). Default value for this parameter is 30 minutes. Chang-
ing the interval as well as learning the current value is only possible via AT commands.
The modem provides continuous monitoring of pins and checks for incoming
1
SMS messages. The modem
checks for SIM cards and switches to the service mode if both trays are not available.
1
SMS messages received by the modem. Such message may contain the command to connect to the server, enable or
disable the offline mode or to control the modem pins. For more details on the modem SMS commands, refer to sections
"Connecting to the Server via SMS Commands"
,
и
"GPIO Pins Control via SMS Commands"
.
