SYSTEM FOR SUPERVISING STUFF MULTIPLEXING DEVICE

摘要

PURPOSE:To reduce the scale of a supervisory circuit and to improve reliability by adding a bit of parity information to a stuff pulse in a multiplexing format and checking a parity bit. CONSTITUTION:Stuffing is executed by the 'misalignment' of a phase difference and a stuff pulse is inserted in accordance with a high-order group multiplexing format. The stuff pulse is used as a parity bit, the number of marks of the data bit until the stuff pulse is inserted is counted, and in the case of an even number, '1' is inserted as the parity bit or '0' is inserted. Respective low-order group signals count the number of marks in parity checking circuits 81, 82-8n, check an even parity or an odd parity and obtain the matching with the parity bit. Here, when a hard fault exists, the matching cannot be obtained and the can be discovered.