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2. Product Overview
2.1. Product Purpose and Main Functions
The iRZ ATM GSM/GPRS modem provides data transmission over GPRS via TCP/IP protocol stack. The
device is designed for operation in telemetry systems.
The modem can operate in any of the three modes: client, server or CSD only. In the
Client
mode (hereinaf-
ter
– client modem) the modem is connected to the data collection server and transmits data from an external
device. In the
Server
mode (hereinafter
– modem server), the modem, on the contrary, waits for the client in-
coming connection (for example, from a dispatcher computer) on a certain port and processes it. In the
CSD
Only
mode data is transmitted via CSD (voice channel) with no data transmission over GPRS and the offline
mode available.
For operation in the
Client
mode you can use any SIM card, for operation in the
Server
mode it is recom-
mended to use a SIM card with an external
1
static IP address. For operation in the
CSD Only
mode you can
use any CSD-enabled SIM card.
In the
Client
and
Server
modes the modem automatically connects to GPRS. After that the modem estab-
lishes connection to the specified server (if operating in the client mode) or opens an incoming port and waits
for incoming connections (if operating in the server mode).
The device provides transparent communication between a third-party external devices polling software and
an external device connected to the modem via RS232 interface. The modem tracks the GPRS connection sta-
tus and in case of connection loss, the modem restores it (see section
).
The ATM modem supports the use of two SIM cards providing backup mobile access (see section
).
The client mode supports backup Internet connection
– the main server switches to a backup server in case
of disconnection. Switching between servers is also possible with a signal from the modem GPIO pins (see
section
).
The client modem can operate with a standard server (see section
) or a special-
purpose iRZ Collector server. The iRZ Collector server provides transparent data communication between a
third-party polling software, operating as a client, and the modems which also operate as clients and do not
have static IP addresses (see section
"Working with the iRZ Collector Server"
).
The modem supports data transmission via CSD (voice channel). If there is phone number group enabled in
the modem settings, data transmission over CSD is available in the client and server mode. In addition, ATM
supports a separate mode for data transmission only over CSD.
1
If your company rents an access point (APN) from a mobile network carrier, addresses of the sites for such network will
be internal. In this case it is recommended to use a private static address.
