End of transaction control system

摘要

In an information computer and data processing system where transactions controlled by the system are initiated and set up by a card inserted to a magnetic strip card reader, provisions are made to terminate the transaction and set the card out of the reader in response to certain conditions of the data supplied by the card reader to the system. Each card to be used with the system has a start character encoded at the beginning of characters corresponding to unique variable data identified by that card. An end character always appears at the end of the unique variable data, followed by an LRC (longitudinal redundancy check) character. Each character on the card also is provided with a parity check bit and a provision is made for detecting a parity or LRC error to terminate the transaction and to set the card out of the reader and to similarly terminate the transaction and set the card out of the reader whenever an end character is detected before a start character. A further provision is made for setting a card out of the reader whenever excessive clock pulses are produced by the reader to the rest of the system within a pre-established time limit.