imu383 support 1pps and 1khz pulse synchronization, but not support ZDA and other NMEA TEXT msg.
只支持1pps和1khz同步，不支持ZDA等NMEA TEXT 消息。

confirm your pin connection of MISO, whether some connection problems it is.
such as: disconnect, or short connect to GND or other pins.
could you show some pics of your HW connections?

if possible, could you share with me your SPI drive codes?
pls try the sequence in below when start SPI mode communication(confirm 1&2 pins in P1 area are not connected):

• start the SPI read program in your Master MCU.
• Power on 330BI

other actions:

1. update FW to FW2.1 in https://developers.aceinna.com/code/apps
2. try other register, such as:
   0x37
   
   or try burst read 0x3E
   

generally, no need based on my experience.

yes, you are right.
by falling edge of DRDY, you can get the latest sensor data(3E burst read).
as below pic, this is time sequence from my side.

for 300RI is same connector with MTLT305D, so pls refer to one topic below:
https://forum.aceinna.com/topic/40/pc-cannot-detect-rs232
you need converter of RS232 and usb, 4.9-32V is ok for 300RI.

hi, Amin. working well in my side, and my steps:

1. download codes VG_AHRS 1.1.3 from VSCODE
   2.update codes and keep same with you.
2. compile the new BIN and uploaded it to 300ZI.
3. keep EVK board connected with PC, 4 ports detected in pc, like: com51/52/53/54
4. connected COM52 with 230400 by serial tool uart-assistant, and open the port, waiting
5. keep power on EVK board.
6. take off(disconnect) 300RI and connect 300RI to EVK board again, uart-assistant will receive
   "from debug port
   HelloWorld"

in my view, no mag sensor in Aceinna, are you directly buy from Aceinna？

pls refer to page: https://navview.blob.core.windows.net/web-resources/6020-1395-01 IMU383ZA-400_Datasheet.pdf?_t=1586396706419
also you can find data-sheet in page: https://www.aceinna.com/inertial-systems/IMU383ZA