Airlink Raven GPRS - Manual (Page 40)

Host Modes
32 Cingular GPRS Raven User Guide Version 2.01
Multicast UDP
Multicast UDP results in any data received from the host serial port being sent to all
the clients in the Modbus 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 Modbus IP list. The index numbers in the IP list
aren't used. Configure the Raven as for a normal UDP session. Set the Startup
Mode Default to 3, and the UDP Mode Default to 8 (ATMD83). Configure the
Destination port to match the device port of the remote modems.
TCP PAD Mode
When the Raven is in a TCP session, all characters received on the serial port are
assembled into TCP packets and sent to the mode's 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 (ex. ATDT192.168.3.23/3456)
• TCP auto answer is enabled (S0), a TCP connection request is received, and the
modem is not in a data session.
• Data is received on the serial port and
• The Startup Mode Default (MD) is 4 (auto TCP)
• The remote TCP destination, as defined in S53, successfully responds to the
TCP connection request.
The value of S7 (TCP Connection Time-out) specifies the number of seconds to
wait, after initiating a TCP connection attempt, for a successful connection to be
established. If the connection has not been successfully established before the time-
out occurs, ERROR/BUSY is returned.