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Page 74 of 102
8 Bootloader
The program for the DLU Data logger can be changed via an interface. The program is
divided into two parts:
1. Bootloader
2. Firmware
The bootloader is programmed at the factory during production of the device and can not be
changed in the field. The application program (firmware) can be changed in the field using
the bootloader. The bootloader can receive the firmware via one of the following interfaces:
-
Serial interface (virtual COM port, see marking "1" in
Figure 1: Map of the
connections
)
-
SD-card
The X-Modem protocol with CRC is used for data transmission via the serial interface. The
program file (firmware) is in format Extended-Intel-Hex.
The following steps take place when the Data logger is restarted.
1. Start Bootloader
2. Approx 10s waiting for receiving firmware or a firmware file to be recognized on the
SD card.
3. Programming the firmware if a firmware is detected in step 2.
4. Start the firmware.
If no SD card with firmware is inserted, the boot loader issues the following message when
restarting:
The number behind "Wait time:" is decremented to 0 every second. This means, that the
Data logger DLU waits 10 seconds for the receipt of a firmware or the recognition of a
firmware file on the SD card.
Bootloader V02.02
Wait time : 10s
Figure 43: Message when restarting with SD card without bootloader