User guide

User Guide
7
7. General Principles of Operation
Once the PPP setting is enabled on a giving serial port the datalogger will
immediately try to establish a PPP connection. It repeats the dial attempt every
few seconds. If the modem is able to dial and everything is set correctly a
successful connection will take 5-10 seconds to establish.
7.1 Using systems with fixed, public IP addresses
If you have a fixed IP service, once connected the logger will be able to accept
incoming connections for the service you have enabled. If you connect to the
logger for normal datalogger communications (via the Pakbus/TCP server socket)
the datalogger will automatically start to send beacon messages once per minute to
the device that called. This will hold the connection open (some GPRS providers
will cut-off inactive connections) and also proves the connection works, but does
incur data traffic charges. (See the help within Loggernet for connecting via an IP
port – the port number must match that set for the Pakbus/TCP Server port in the
logger.)
With a public IP address, Loggernet should be able to call out to the logger on
demand. You can prevent the extra traffic from the Loggernet end by unchecking
the box on the Pakbus port that forces it to stay open.
With a fixed IP it should also be possible for multiple PCs to call the same logger
either for data collection or connecting to the logger’s web or ftp server functions.
If you choose to do this though be careful to ensure the logger has an adequate
power supply to support multiple and lengthy connections and also check that you
are certain the traffic costs do not get out of hand.