> For the complete documentation index, see [llms.txt](https://px4.gitbook.io/px4-user-guide/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://px4.gitbook.io/px4-user-guide/development/middleware/msg_docs/ulogstreamack.md).

# UlogStreamAck

Ack a previously sent ulog\_stream message that had the NEED\_ACK flag set

[source file](https://github.com/PX4/PX4-Autopilot/blob/main/msg/UlogStreamAck.msg)

```c
# Ack a previously sent ulog_stream message that had
# the NEED_ACK flag set

uint64 timestamp		# time since system start (microseconds)
int32 ACK_TIMEOUT = 50		# timeout waiting for an ack until we retry to send the message [ms]
int32 ACK_MAX_TRIES = 50	# maximum amount of tries to (re-)send a message, each time waiting ACK_TIMEOUT ms

uint16 msg_sequence

```