| 摘要 |
PURPOSE:To prevent waste of paper, by inhibiting continuous printing of special symbols by software control, in case of the failure of a computer and a printer. CONSTITUTION:When there exists an abnormal waveform where a data line is kept to the same logic as a start bit, a 1sec timer is operated by detecting the H level of the data line at the beginning of serial data receiving after the application of power supply and it is the same level as the start bit. If the start bit is not recovered because of consecutive 1sec or over, the bit is processed in timeout and the processing passes through a serial receiving processing routine. Thus, no printing is performed. In case of the abnormal waveform in which the level of data line is kept the same logic as that of the start bit, since no stop bit is detected, the received data for one byte's share is converted into a special code as the undefined code, the processing passes through a data receiving routine and transfers to the next receiving routine. |
