User Manual

Table Of Contents
SARA-R4/N4 series-AT Commands Manual
UBX-17003787 - R11
18Internet protocol transport layer
Page 197 of 308
Parameter Type Description
1: HEX mode enabled
18.16Set socket in Direct Link mode +USODL
+USODL
SARA-R404M SARA-R410M-01B SARA-R410M-02B SARA-R410M-52B SARA-R412MModules
SARA-N4
Syntax PIN required Settings saved Can be aborted Response time Error referenceAttributes
full No No No < 1 s +CME Error
18.16.1Description
Establishes a transparent end to end communication with an already connected TCP or UDP socket via the
serial interface. The data can be sent to the socket and can be received via the serial interface: the HW flow
control usage is strongly recommended to avoid data loss.
The transparent TCP/UDP connection mode can be exited via the +++ sequence, entered after at least 2
s of suspension of transmission to the port. The socket will remain connected and communication can be
re-established any time.
The +UDCONF=5, +UDCONF=6, +UDCONF=7, +UDCONF=8 commands allow the configuration of UDP and TCP
direct link triggers.
When using Direct Link with UDP sockets, if no network signal is available, outgoing UDP packet may be
lost.
SARA-R404M / SARA-R410M-01B / SARA-R410M-02B
The HW flow control is not supported.
18.16.2Syntax
Type Syntax Response Example
Set AT+USODL=<socket> CONNECT AT+USODL=0
CONNECT
Test AT+USODL=? +USODL: (list of supported
<socket>s)
OK
+USODL: (0-6)
OK
18.16.3Defined values
Parameter Type Description
<socket> Number Socket identifier. The range goes from 0 to 6.
18.16.4Enhanced Direct Link
The enhanced DL functionality allows the user set up to three kinds of trigger for data transmission:
Timer Trigger
Data Length Trigger
Character Trigger
The triggers can be applied independently to each socket. A socket may be set with more than one trigger.
The trigger must be set after the socket creation and before switching to direct link mode.
By default Timer Trigger and Data Length Trigger are enabled for UDP sockets.
By default no triggers are enabled for TCP sockets.
See the +UDCONF=5, +UDCONF=6, +UDCONF=7, +UDCONF=8 commands description for the transmission
triggers configuration.