Diagnostic Testing of CCITT V.35 and X.21 Interfaces
Original Publication Date: 1986-Jul-01
Included in the Prior Art Database: 2005-Mar-09
This invention was developed to provide a diagnostic test for interfaces. These tests are used by the customer to prove that the system is fault-free when a possible phone company problem or modem problem exist. As a result, the system service cost is reduced. This invention eliminates the need for the system to be attached to a modem with diagnostic capability in order to verify that the system hardware and cables are operating correctly. In previous implementations, the modem was needed to provide a diagnostic clock. A diagnostic clock is multiplexed with an existing driver circuit (in diagnostic mode only). In one embodiment, additional electronics are added to a V.35 interface and a wrap connector is provided for the modem end of the cable. The chart below shows the signal names that are defined.