PSDK示例出现command async send error，请问是我哪个环节出问题，平台是STM32F407VE

运行log

[0.000][core]-[Info]-[DjiCore_Init:88) Payload SDK Version : V3.0.0-beta.0-build.999
[0.221][adapter]-[Info]-[DjiAccessAdapter_Init:148) Identify aircraft series is Matrice 300 Series
[0.221][adapter]-[Info]-[DjiAccessAdapter_Init:165) Identify mount position type is Payload Port Type
[0.223][adapter]-[Info]-[DjiPayloadNegotiate_Start:199) Waiting payload negotiate finished.
[1.223][adapter]-[Info]-[DjiPayloadNegotiate_Start:203) No need wait negotiate finished
[1.224][adapter]-[Info]-[DjiPayloadNegotiate_Start:199) Waiting payload negotiate finished.
[2.224][adapter]-[Info]-[DjiPayloadNegotiate_Start:203) No need wait negotiate finished
[4.237][linker]-[Warn]-[DjiCommand_SendAsyncHandle:856) Command async send retry: index = 0, retryTimes = 3, cmdSet = 25, cmdId = 50
[5.238][linker]-[Warn]-[DjiCommand_SendAsyncHandle:856) Command async send retry: index = 0, retryTimes = 2, cmdSet = 25, cmdId = 50
[6.239][linker]-[Warn]-[DjiCommand_SendAsyncHandle:856) Command async send retry: index = 0, retryTimes = 1, cmdSet = 25, cmdId = 50
[7.240][linker]-[Error]-[DjiCommand_SendAsyncHandle:872) Command async send error 0
[7.240][linker]-[Error]-[DjiCommand_SendSync:475) sendSync callback timeout
[7.240][infor]-[Error]-[DjiMountPosition_GetOnPayloadPort:89) get payload mount position error: 0x000000E1.
[7.240][infor]-[Error]-[DjiAircraftInfo_Init:230) Get sdk mount position error. Probably the DJI SDK Adpater has not binded. Please check the bind state of the DJI SDK Adpater and bind it.