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run_prearm_checks

PX4 capability domain: system-control. PX4 mapping: MAV_CMD_RUN_PREARM_CHECKS. Instructs a target system to run pre-arm checks. This allows preflight checks to be run on demand, which may be useful on systems that normally run them at low rate, or which do not trigger checks when the armable state might have changed. This command should return MAV_RESULT_ACCEPTED if it will run the checks. The results of the checks are usually then reported in SYS_STATUS messages (this is system-specific). The command should return MAV_RESULT_TEMPORARILY_REJECTED if the system is already armed.

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Request Params

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vendor
string
必填
Fixed value px4
​
device_id
string
必填
Target PX4 device ID
​
command_type
string
必填
Fixed value run_prearm_checks
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idempotency_key
string
必填
Idempotency key; repeated requests return the same command
​
timeout_seconds
integer
Timeout in seconds, range 0~300
​
payload
object
必填
Empty object {}

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PX4 Frame Mapping

  • MAVLink command: MAV_CMD_RUN_PREARM_CHECKS
  • Command ID: 401
  • Default transport: COMMAND_LONG
  • Source XML: common.xml
  • Completion: COMMAND_ACK
  • Guard: real PX4 downlink is disabled by default; guarded mode requires explicit authorization and a ready transport.

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Create Response

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command_id
string
Platform command ID, used for follow-up queries
​
status
string
Acceptance status: ACCEPTED
​
accepted_at
string(datetime)
Command acceptance time (UTC)

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Query Response

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command_id
string
Platform command ID
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status
string
Execution status: ACCEPTED / DELIVERED / SUCCEEDED / FAILED / TIMED_OUT / UNMATCHED_RESPONSE
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vendor
string
Vendor identifier; fixed value px4
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device_id
string
Target PX4 device ID
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command_type
string
PX4 command type
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response_code
string
Mapped COMMAND_ACK.result value
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response_message
string
PX4 acknowledgement summary
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vendor_response
object
Raw PX4 acknowledgement summary, including MAVLink command ID and transport

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PX4 ACK Mapping

After sending the frame, the PX4 agent waits for COMMAND_ACK and correlates the response by command id. Disabled mode sends no frame and completes with a rejected lifecycle result. 
curl -X POST "/api/v1/open/downlink/commands" \
  -H "Content-Type: application/json" \
  -H "X-Api-Id: YOUR_API_ID" \
  -H "X-Api-Timestamp: YOUR_UNIX_SECONDS" \
  -H "X-Api-Nonce: YOUR_NONCE" \
  -H "X-Api-Signature: YOUR_SIGNATURE" \
  -d "{\"vendor\":\"px4\",\"device_id\":\"px4-real-1\",\"command_type\":\"run_prearm_checks\",\"payload\":{},\"idempotency_key\":\"req-run_prearm_checks-001\",\"timeout_seconds\":30}"

curl "/api/v1/open/downlink/commands/8cdb5bf3-8902-c5f7-f9aa-dc7fa0af1de0"

{
  "command_id": "8cdb5bf3-8902-c5f7-f9aa-dc7fa0af1de0",
  "status": "ACCEPTED",
  "accepted_at": "2026-06-15T00:00:00Z"
}