User Manual

Table Of Contents
SARA-R4/N4 series-AT Commands Manual
UBX-17003787 - R11
18Internet protocol transport layer
Page 195 of 308
18.13.4Notes
Each packet received from the network is stored in a separate buffer and the command is capable to read
only a packet (or e portion of it) at time. This means that if <length> is greater than the packet size, the
command will return a maximum amount of data equal to the packet size, also if there are other packets
in the buffer. The remaining data (i.e. the remaining UDP packets) can be read with further reads.
The returned data may have any kind of ASCII character in the range [0x00,0xFF] i.e. control characters
too. The starting quotation marks shall not be taken into account like data; the first byte of data starts
after the first quotation marks. Then the other characters are provided for a <length> amount. At the
end of the length byte stream, another quotation marks followed by <CR><LF> are provided for user
convenience and visualization purposes. An application should rely on the <length> info to count the
received number of characters (after the starting quotation marks) especially if any protocol control
characters are expected.
If an application deals with letter and number characters only i.e. all of the expected characters are
outside the [0x00, 0x1F] range and are not quotation marks, the AT+USORD response quotation marks
can be assumed to identify the start and the end of the received data packet, anyway the <length> field
usage to identify the valid data stream is recommended.
When <length>= 0, the command returns the total amount of data present in the network buffer.
Example: 23 unread bytes in the socket
AT+USORF=3,0
+USORF: 3,23
OK
If the HEX mode is enabled, the length of <data> will be 2 times <length>.
18.14Set Listening Socket +USOLI
+USOLI
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 (except
URC)
TCP/UDP/IP
Error +CME
Error
18.14.1Description
Sets the specified socket in listening mode on the specified port of service, waiting for incoming connections
(TCP) or data (UDP):
For TCP sockets, incoming connections will be automatically accepted and notified via the
URC +UUSOLI: <socket>,<ip_address>,<port>,<listening_socket>,<local_ip_address>,<listening_port>,
carrying the connected socket identifier, the remote IP address and port.
For UDP sockets, incoming data will be notified via URC +UUSORF: <listening_socket>,<length>. To know
from which remote IP address and port the data is coming from, use the AT+USORF command.
18.14.2Syntax
Type Syntax Response Example
TCP sockets
AT+USOLI=2,1200
OK
+UUSOLI: 3,"151.63.16.7",1403,2,
"82.89.67.164",1200
Set AT+USOLI=<socket>,<port> OK
UDP sockets
AT+USOLI=0,1182
OK
+UUSORF: 0,1024