SENA LS110 - Manual (Page 36)

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port, and send back the data from the serial port to the latest remote host who sent the UDP
datagram. Virtual connection timeout will be reset to inactivity timeout value whenever there is any
data transfer between remote host and the serial device. If other remote hosts send UDP datagrams
while a virtual connection is established, the UDP datagram will be discarded. If there is no data
transfer during inactivity timeout, the virtual connection will be closed and other remote hosts can
access the LS110 from then on.
2) Parameters
 Local port
The concept is the same as that of TCP communication. See 4.1.2 TCP Server Mode Operations
for details.
4.1.7 Modem Emulation Mode Operations
In modem emulation mode, the serial port process acts as if it is a modem attached to the serial
device. It accepts and sends AT modem commands, and answers to them, as modems would. It also
handles the modem signals correctly. Modem emulation mode is useful in the following cases.
 There already exists a modem attached to the users’ serial device.
If users’ serial device already has a modem for phone-line connection, it can be just replaced by
the LS110 for Ethernet connection. What users need to do is to use an IP address (or domain
name) instead of phone number as a parameter of ATA/ATDT commands.
 It is required to send serial data to the multiple remote hosts.
If the serial device should send data to the multiple hosts, modem emulation mode is required.
For example, the first data from the serial device can be sent to the first data acquisition server
and the second to the second server. What user device has to do is to change the IP address (or
domain name) parameter whenever the device sends ATD(T) XXX command.
By using the modem emulation mode of the LS110, users can have their serial device connected to
the Ethernet network easily. Table 4-3 is a summarized AT command table which the LS110 supports.
Table 4-4 is a summarized AT commands response numeric codes. Figure 4-7 shows the typical case
of the serial port command flow when AT command is used to connect to the Ethernet network.