| 摘要 |
<p>This invention relates to a switching system testing arrangement which uses a looparound circuit, into which a test signal is injected and received to determine whether the loop is functioning properly. The system provides means for testing individual switches (or equivalent time division counterpart), individual loops and links between switching stages and the network, complete loops between peripherals, short loops between peripherals and their local control units, or any loop that can be set up within the system, without incurring loss of use of parts of the system which would otherwise be required to obtain the loop but are not of interest to test. The control data and test signals are applied, to set up the loop and into the loop respectively, via message transmission paths which are separate from the loop under test. Accordingly any part of the communication circuit system can be isolated for test, reducing substantially the time overhead for determining whether a switching element or stage, or link is operating properly.</p> |
