A common channel signalling system device which receives an indication for each signal unit found in error and that measures the rate of occurrence of errors according to a prescribed rule.; 一種公用信道信令系統(tǒng)設(shè)備,用于接收每一個有錯誤的信號單元中的指示,并根據(jù)預(yù)定的 規(guī)則測量出錯率。