摘要 |
A device for reading magnetically encoded data on a document, such as a strip of characters printed in magnetic ink along the lower edge of a check, executes a subroutine to determine whether each character, as it is read, is legitimate. This error detection may be done by comparing recognized code patterns with legitimate code patterns, or by comparing a signal representing the strength of the signal derived from the output of the magnetic read head reading the data with a predetermined level. If an error is detected, the magnetically encoded data is read and checked again, as often as need up to a predetermined number of attempts to read the data.
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