cleared iocb for channel 0
cleared iocb for channel 1
cleared iocb for channel 2
cleared iocb for channel 3
cleared iocb for channel 4
cleared iocb for channel 5
cleared iocb for channel 6
cleared iocb for channel 7
cleared iocb for channel 8
cleared iocb for channel 9
cleared iocb for channel 10
cleared iocb for channel 11
cleared iocb for channel 12
cleared iocb for channel 13
cleared iocb for channel 14
cleared iocb for channel 15