Integration Manual

SARA-R4/N4 series - System Integration Manual
UBX-16029218 - R11 System description Page 46 of 157
FTP files can also be transferred using FTP Direct Link:
 FTP download: data coming from the FTP server is forwarded to the host processor via USB / UART
serial interfaces (for FTP without Direct Link mode the data is always stored in the module’s flash file
system)
 FTP upload: data coming from the host processor via USB / UART serial interface is forwarded to the
FTP server (for FTP without Direct Link mode the data is read from the module’s flash file system)
When Direct Link is used for an FTP file transfer, only the file contents passes through USB / UART serial
interface, whereas all the FTP command handling is managed internally by the FTP application.
For more details about embedded FTP functionalities, see the SARA-R4/N4 series AT Commands Manual
[2].
1.13.6 HTTP
SARA-R4/N4 series modules provide the embedded Hypertext Transfer Protocol (HTTP) services via AT
commands for sending requests to a remote HTTP server, receiving the server response and transparently
storing it in the module’s flash file system. For more details, see the SARA-R4/N4 series AT Commands
Manual [2].
1.13.7 Firmware update Over AT (FOAT)
This feature allows upgrading of the module firmware over the AT interface, using AT commands.
The +UFWUPD AT command enables a code download to the device from the host via the Xmodem
protocol.
The +UFWINSTALL AT command then triggers a reboot, and upon reboot initiates a firmware installation
on the device via a special boot loader on the module. The bootloader first authenticates the downloaded
image, then installs it, and then reboots the module.
Firmware authenticity verification is performed via a security signature. The firmware is then installed,
overwriting the current version. In case of power loss during this phase, the boot loader detects a fault at
the next wake-up, and restarts the firmware installation. After completing the upgrade, the module is reset
again and wakes-up in normal boot.
For more details about Firmware update Over AT procedure, see the SARA-R4/N4 series AT Commands
Manual [2], +UFWUPD AT command.
1.13.8 Firmware update Over The Air (uFOTA)
This feature allows upgrading the module firmware over the air interface, based on u-blox client/server
solution (uFOTA), using LWM2M.
For more details about firmware update over-the-air procedure, see the SARA-R4/N4 series AT Commands
Manual [2].