Sierra Wireless RAVEN 1X 20070914 - Manual (Page 68)

Data Communication and Host Modes
Rev 3.0B Feb.08 63
until it receives an acknowledgement with this sequence
number. If an acknowledgement is not received within the
time‐out period (specified in S7), the data will be retrans‐
mitted. This will continue until an acknowledgement is
received or the modem is reset. Likewise any UDP packets
received by the Raven are expected to have this simple header.
The Raven will issue an acknowledgement for any valid
packets which are received.
To configure the Raven for a normal UDP session, you need to
set the Startup Mode Default to 73 (ATMD73). If you are using
two modems, configure the Destination IP and Port in each to
point to each other. Serial data will then be sent reliably
between the two.
Caution: Although it adds reliability, the simple implementation of the
Reliable UDP mode in the does not check for duplicate packets.
UDP Multicast Mode
UDP Multicast mode results in any data received from the host
serial port being sent to all the clients in the address list. The
remote port number is taken from S53. To avoid flooding the
network, the packets are sent to each client with a 20ms pause
in between. The receipt of UDP packets works as in normal
UDP mode (i.e. bound by the value S53 and/or AIP). Since it
may take a while to transmit the data to all hosts (especially if
all 20 Modbus entries are used and name resolutions are
required), new data received from the host port is buffered
until current transmissions to all hosts are finished.
Enter the list of target IPs in the address list (ADDR LIST). The
index numbers in the list arenʹt used. Configure for a normal
UDP session. Set the Startup Mode Default to 83 (ATMD83).
Configure the Destination port to match the device port of the
remote modems.
TCP and TCP Pad
When the Raven is in a TCP session, all characters received on
the serial port are assembled into TCP packets and sent to the
modeʹs remote IP address/port, and any packets received from
the remote end of the TCP connection are disassembled and
dumped onto the serial line.
A TCP connection is established by one of the following
methods:
• Using the Dial TCP (DT) AT command. For example,
ATDT192.168.3.23/3456.