这是说怎么设置采样频率吗？
http://wenku.baidu.com/link?url=rB1-zHfEPMJhHKZz-TC4I0nmS2hVZZ3CaKtaEhY90AODZVAVB4WE1LxTaOCBzoJ6d7p2uz9F4fGr-4sNmBf3J2rD8EPgU4oXQ4vZ_pU_uUq
