| 摘要 |
<p>A circuit arrangement is provided for testing electrical characteristics of both analog and digital trunk lines connected to a transit telephone exchange of digital type comprising a central control unit CC for controlling switching of codes in a connection network RC. The circuit arrangement includes an interface unit UIR for the connection network, an analog trunk line testing unit UPA, a digital trunk line testing unit UPD, a stored program microprocessor MIP operating in time division multiplex, or an interface UIC for the central control unit. <IMAGE></p> |
