# ActuatorOutputs (UORB message) [source file](https://github.com/PX4/PX4-Autopilot/blob/main/msg/ActuatorOutputs.msg) ```c uint64 timestamp # time since system start (microseconds) uint8 NUM_ACTUATOR_OUTPUTS = 16 uint8 NUM_ACTUATOR_OUTPUT_GROUPS = 4 # for sanity checking uint32 noutputs # valid outputs float32[16] output # output data, in natural output units # actuator_outputs_sim is used for SITL, HITL & SIH (with an output range of [-1, 1]) # TOPICS actuator_outputs actuator_outputs_sim actuator_outputs_debug ```