| 摘要 |
<p>A signal transfer control system of PC (programmable controller) for transferring input/output signals to and from external units. An I/O unit (26) has an input/output signal region (1) for storing input/ouput signals relative to an external unit, and a mapping data (2) for defining the mapping of input/output signals (1). A RAM (23) on the PC side has a point data (3) for defining a destination address from the mapping data (2), and has an input/output data region (4) for storing the input/output signals. The input signals are stored in the input/output signal region (1) and are mapped by the mapping data (2) for each of the input signals. The point data (3) determines the destination of the mapped input signal. The destination of the input signal is determined by the mapping data (2) and the point data (3), and is transferred to the input/output data region (4). The output signal is transferred from the input/output data region (4) to the input/output signal region (1) by the point data (3) and the mapping data (2) just contrary to the above. Even when the arrangement of the input/output signals is changed, the point data or the mapping data only need be changed to cope with it without changing the sequence program.</p> |
