MAVLink MAV_DATA_STREAM from Board Ardupilot Mega 2

in MAVLink status from flight controller pack together in MAVLink Message
ex. Msg id #30 ATTITUDE consist of roll,pitch,yaw,roll speed,pitch speed,yaw speed

but in case of requesting these msg from flight controller we need to send request to flight controller for MAV_DATA_STREAM and frequency of these stream

MAV_DATA_STREAM  is collection of different msg id group together

MAV_DATA_STREAM 

(https://pixhawk.ethz.ch/mavlink/)

for Adupilot Mega 

RAW_SENSOR
(#27) RAW_IMU
(#29) SCALED_PRESSURE

EXTENDED_STATUS
(#1) SYS_STATUS
(#24) GPS_RAW_INT
(#42) MISSION_CURRENT
(#62) NAV_CONTROLLER_OUTPUT

RC_CH
(#35) RC_CHANNELS_RAW
(#36) SERVO_OUTPUT_RAW

POSITION
(#33) GLOBAL_POSITION_INT

EXTRA 1
(#30) ATTITUDE

EXTRA 2
(#74)VFR_HUD

EXTRA 3
(#2) SYSTEM_TIME

Ref :
https://pixhawk.ethz.ch/mavlink/