Ok I got it, thank you so much!
Instead regarding last question which is:
I was looking at .dat file and I did a query (VelN) and I got these columns-> ['IMU_ATTI(0):velN', 'IMUCalcs(0):velN:C', 'IMUCalcs(0):diffVelN:C', 'IMU_ATTI(1):velN', 'IMUCalcs(1):velN:C', 'IMUCalcs(1):diffVelN:C']
But...