User's Manual

CHAPTER2
InstallingtheRTU
14
GPRSDNS "[ipaddress]"
where [ipaddress] is the DNS server address of your
GPRS network operator (optional)
Note: When using an Internet firewall in front of the LAN where the A850
Telemetry Gateway resides, be careful to properly configure the
firewall and the GPRSCONNADDR parameters [a850-ipaddress] and
[portnumber]. This is particularly important if you use NAT (network
address translation) on your firewall.
You should also understand that a "home-grade" router may be not
sufficient for this application. Adcon strongly recommends that you
use professional router equipment.
ConfiguringtheA753ConnectionSettings
Use the following commands to define the intervals the A753 will wake
up and connect to the A850 Telemetry Gateway:
GPRSCONNALIGN [align]
Alignment of calls in seconds (default: 0, i.e. 00:00 =
midnight). This parameter is used to spread the
connections in time to avoid overloading your router or
gateway, which is necessary for large-scale networks.
GPRSCONNINT [interval]
Interval in seconds between two connection attempts
(default: 3600).
GPRSSECRET [secret]
This 32-bit integer (0 -4294967295) has to be set for
the A753 and the gateway. The integer is a shared
"secret" or password used as a lock-out mechanism to
avoid connections to foreign gateways.
GPRSTMOUT [interval]
Idle timeout in seconds (default: 3600); connections
that are idle this long will be terminated by the A753.
This helps to detect silently deceased TCP connections.
After entering all parameters correctly, you can check your settings at
any time by entering the INFO 2 command. With the GPRS
parameters set, the response will be similar to the following:
# INFO 2
42395 INFO
Features: none
GSM timeout: 40
GPRS timeout: 3600
Access point: business.adcon.at "" ""
Connect interval: 120 0
Connect to: 172.47.13.153 83 0