Sierra Wireless 20070914 - Manual (Page 82)

Data Communication and Host Modes
Rev 3.0B Feb.08 69
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 PinPoint X 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 disas‐
sembled 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.
• TCP auto answer is enabled (S1), 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, success‐
fully 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.
TCP packet assembly is affected by the values of S50 (PAD
Forwarding Time‐out) and S51 (PAD Forwarding Character).
Data received in the serial buffer will be transmitted when the
idle inter‐character time‐out specified in S50 (in tenths of
seconds) occurs or when a character is received that matches
S51 (if non‐zero).