May be already damaged by misoperation, we are trying to find solution for you, pls wait.

"Before installing it, the IMU doesn't output any data such as acceleration, gyro."
when got it from plant, it should be working well. but your unit configuration not right, so after you received before installing IMU, what actions did you do?

@rintaro pls check the attached FW for 300RI, and upgrade it by Configuration-->Upgrade Firmware, and then pls check whether right data send out or not?
pls note:

• 300RI data analysis only supported by [python driver] (https://developers.aceinna.com/devices/connect) eventhough it can also be upgraded by NAV-VIEW,

• after connected by ANS web, 300RI will not send UART data at first(for output data rate is 0hz defaultly), so still need to change seting--ODR to none 0hz value.
  
  5020-3309-01_OpenIMU300RI_1.1.0_plant.bin
  Wait your feedback.

You mentioned "Before the installation, the device seemed to be always BOOTLOADER mode ", here their is problem.
It should be working well after delivered out by our plant, so after you received what did you do?

What is your meaning of "the installation", is it upload one 300ZI/ZA bin file to 300RI?

pls try to use master or bugfix branch.
or you can you executable program directly, download: https://developers.aceinna.com/devices/connect. operating and record:https://developers.aceinna.com/devices/record-next

https://forum.aceinna.com/topic/93/top-topics-of-common-operations-with-openimu-products, topic_2 pls check e2 packet example.

online doc also mentioned the crc in "3.6 16-bit CRC-CCITT" of https://openimu.readthedocs.io/en/latest/software/UARTmessaging.html#openimu-uart-messaging-framework

@akofler I am still in home office, and cannot to do deep investigation with some HWs, so cannot reply to you which is the right actions in your side, if good luck, next week can reply to you, thanks for your waiting.
how many parts in your side totally? and how many of them cannot work?

already send it to you by email, when my previous reply. Pls receive and check your email box

@Amin you mentioned: " I can program the module with my built images from the source code and downloaded images from the website" and " I have programmed the 1908811027_ 1.0.2_a2.bin into my module", what is starting address when you upload it several times? i need to judge whether factory calibration data is broken or not.

Your module is 300ZA, pls do not use 1908811027_ 1.0.2_a2.bin which is belong to 300RI unit.
Refer to backup steps in topic_4, pls backup your current whole bin whatever it is working ok or not.
In future 2 weeks, maybe i can only working in home due to the pneumonia control, and cannot make the right bin for you which have the right calibration data.
Currently, only share with you other SN whole bin(1908400166_1.1.0.bin) by email, pls upload based on steps topic_4

1. After update BIN from "/code/apps", did it success at last?
2. pls check the serial data from 300RI, steps refer to 8. how to check the serial data by serial tool?
3. how about the performance of python-openimu? or try to connect with SW from link