PX4-Autopilot/docs/en/msg_docs/UlogStream.md

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UlogStream (UORB message)

Message to stream ULog data from the logger. Corresponds to the LOGGING_DATA. mavlink message.

TOPICS: ulog_stream

Fields

Name	Type	Unit [Frame]	Range/Enum	Description
timestamp	uint64			time since system start (microseconds)
length	uint8			length of data
first_message_offset	uint8			offset into data where first message starts. This
msg_sequence	uint16			allows determine drops
flags	uint8			see FLAGS_*
data	uint8[249]			ulog data

Constants

Name	Type	Value	Description
FLAGS_NEED_ACK	uint8	1	if set, this message requires to be acked.
ORB_QUEUE_LENGTH	uint8	16	TODO: we might be able to reduce this if mavlink polled on the topic

Source Message

Source file (GitHub)

::: details Click here to see original file

# Message to stream ULog data from the logger. Corresponds to the LOGGING_DATA
# mavlink message

uint64 timestamp		# time since system start (microseconds)

# flags bitmasks
uint8 FLAGS_NEED_ACK = 1	# if set, this message requires to be acked.
				# Acked messages are published synchronous: a
				# publisher waits for an ack before sending the
				# next message

uint8 length			# length of data
uint8 first_message_offset	# offset into data where first message starts. This
				# can be used for recovery, when a previous message got lost
uint16 msg_sequence		# allows determine drops
uint8 flags			# see FLAGS_*
uint8[249] data		# ulog data

uint8 ORB_QUEUE_LENGTH = 16	# TODO: we might be able to reduce this if mavlink polled on the topic

:::