PURPOSE:To detect a fault on a network without adding any special function to a slave station by comparing a maximum value for each frequency band over a broad band detected by a maximum value detection means with a permissible signal level corresponding to the frequency band stored in a storage means. CONSTITUTION:A distribution means M3 extracts a signal sent/received among plural independent devices M1 in a broad band network M2 and the signal is distributed by a maximum value detection means M4. Each frequency band of a carrier included in a signal at a broad band is stored in a storage means M5 together with a permissible level. A indicated output means M6 outputs each frequency band as an indicated value and the maximum value detection means M4 detects a maximum value for each frequency band. Then a fault detection means M7 compares the detected maximum value with the permissible signal level corresponding to the frequency band stored in the storage means M5 to detect a faulty state. Thus, a fault on the network is detected without adding a special function to a slave station.
展开▼
