In data communications , the transmission of acknowledgment ( ack ) characters from the receiving device to the sending device indicates the data sent has been received correctly 數(shù)據(jù)通信中,接收設(shè)備向發(fā)射設(shè)備發(fā)送確認(rèn)( ack )字符表示發(fā)送數(shù)據(jù)已經(jīng)正確接收。