Loop system for data processors - reduces waiting time in on=line operation when one terminal is non-operational

摘要

The loop system is designed to reduce waiting time in the event of a data terminal being out of action. The system incorporates an interface which is placed between a modem and the data terminal. The interface has a data switch which is connected to a serial-parallel converter (37). The output is connected via an address encoder (39) to a microprocessor (40) acting as address detector and acknowledgement generator. When one terminal is out of service, the microprocessor calls up the previously stored acknowledgement signal from a memory (44) and sends it to the modem. The central computer instead of waiting, is instructed to switch to the next terminal in the series to be interrogated.