| 摘要 |
PURPOSE:To identify a faulty point on an interface path by duplicating the interface, setting the states respectively, and reading each setting state via the different interface. CONSTITUTION:When the interface 3-A is used as an active path and the 3-B is used as a spare path, a test state setting is indicated from the primary station to the secondary station 2-i. The secondary station 2-i until the path where the 3-A is operated normally is decoded by a reception control section 12-A and the test state is set and held by a state setting section 13-A. Then the primary station changes over the 3-A to the 3-B to read the state of all the secondary stations set to the state setting section 13-A. In this case, a transmission/reception control section 12-B is used. The primary station decides that up to the path of the interface 3-A of the secondary station where logical 1 being the result of test state read is consecutive is normal, and the interface of the secondary station where the consecutive logical 2 changes to logical 0. |
