Message Rates
MAV_CMD_SET_MESSAGE_INTERVAL can be used to dynamically set the message streaming rates of a MAVLink component, provided the protocol is supported at both ends. This is mainly useful over unpredictable links, such as the telemetry link to a GCS, where the required message streams depend on the particular GCS in use, and channel quality depends on distance and the radio used.
This section provides guidance on configuring MAVLink message rates using the MAV_CMD_SET_MESSAGE_INTERVAL command.
Configuring Message Rates
MAV_CMD_SET_MESSAGE_INTERVAL can be used to increase or decrease the rate of individual messages for QoS management — for example, reducing unnecessary telemetry on a bandwidth-constrained link, or increasing the rate of a specific message needed by a companion computer.
The interval set by this command only applies to the link (connection) the command was received on. To configure rates on a specific serial port, send the command over that port.
To silence a message, set param2 (interval in microseconds) to -1. To restore the default rate, set the interval to 0.
INFO
Flight stacks commonly use parameters to set default streaming rates, which are then overridden by MAV_CMD_SET_MESSAGE_INTERVAL. On ArduPilot, these are MAVn_* parameters. On PX4 these are MAV_*_RATE parameters.
Example Configuration
Disable a pair of IMU sensor messages, and request RAW_IMU at 200 Hz:
| 消息 | Interval (us) | 备注 |
|---|---|---|
RAW_IMU (id: 27) | 5000 | 200 Hz for EKF input |
SCALED_IMU2 (id: 116) | -1 | Disabled |
HIGHRES_IMU (id: 105) | -1 | Disabled |
Streaming to the Autopilot
MAV_CMD_SET_MESSAGE_INTERVAL should be used to control streaming rates, if supported, when streaming unpredictable content over unreliable links.
When using predictable links with a predictable endpoint, such as a companion computer, it is more usual to hard code the streaming rates and messages sent. For example, VISION_POSITION_ESTIMATE would be sent at a fixed rate because the link to the companion computer is usually a high-speed serial/Ethernet link.
Implementations
Supported on PX4 v1.11+ and ArduPilot v4.0+. Behavior on older versions of these two autopilots is undefined.