RLXIC-SV
♦
Intelligent Cellular
Data Communication and Host Modes
RadioLinx Intelligent Cellular Serial Modem for the Verizon Wireless CDMA Network
User Manual
Page 64 of 146
ProSoft Technology, Inc.
May 29, 2009
7.3.2 SLIP
SLIP mode is entered be using the "
AT\ASLIP
" command. As in PPP Mode, the
IP address that the host assumes is affected by the setting of
*HOSTPRIVMODE. SLIP does not negotiate the IP address with the connected
device or computer, so before making a SLIP connection, the SLIP driver on that
device or computer must be configured to use the IP address specified by
querying
S110
.
When the modem is in UDP PAD (Packet Assembly and Disassembly) Mode,
all characters received on the serial port are assembled into UDP packets,
and sent to the remote IP address/port or the RLXIC-SV, and any packets
received from the same IP/port-destined for the device port of RLXIC-SV (see
*DPORT)--are disassembled, and dumped onto the serial line.
A UDP session is initiated by one of the following events:
Using the Dial UDP (DP) AT command (example, ATDP192.168.3.23/3456).
Setting the Startup Mode Default (MD) to 3 (UDP) so that a UDP session is
entered automatically when the modem registers onto the network. Serial
data will be sent to the IP/port specified in S53.
Incoming UDP packets will be processed out the serial port if
UDP auto answer is enabled (S82=2);
The destination IP address matches that in S53 (if Friends Mode is enabled,
the IP address also needs to be present on the Friends List);
Or allow any IP is set (AIP=1);
The modem is in AT mode (not in a current UDP or TCP session).
UDP 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).
7.3.3 UDP
Auto
Answer
UDP auto answer (previously called UDP half-open) is set with S82=2. When set,
the RLXIC-SV will automatically establish a UDP session to the source IP
address, and port of the UDP packet received. The RLXIC-SV will remain
"locked" to this one remote IP/port until no data is sent or received for the time
interval defined in the UDP auto answer time-out (S83). During this session,
packets from other IP/port addresses will be rejected, unless *UALL is set.
Whether or not an incoming packet will cause the modem to enter a UDP session
is always dependent on the S53 and AIP settings.
The Normal UDP Mode (MD3) can be combined with UDP auto answer to cause
the incoming serial data to be sent in UDP packets (instead of being treated as
AT commands), while allowing sessions to be established from different UDP
sources. A UDP session will be initiated either by incoming serial data or by an
incoming UDP packet. The session, started by either method, will be terminated
when no data has been sent or received for the S82 period. After the session
terminates, another may be initiated by either means.
