NC machine tool punched tape testing - using final and intermediate bit summation and sum check

摘要

The method is for testing NC machine tool punched tape data and involves intermediate storage and testing of the data which is transferred from the tape reader in character sized blocks. It is designed for simplicity and reliability. The sum of all characters read is formed in a first control operating mode during transfer of the data. For actual machine control mode the sum is again formed and checked against the original result. The control data set is accepted only upon agreement of the two results. The equipment items are typically a punched paper tape (1), a tape reader (2), a slow-operating summation unit (3), memory (4), comparator (5), and error display unit (6).