| 摘要 |
<p>Interface unit (320) for voltage input signals comprising two or more input channels. The input signals of these two or more input channels (I 1 -I 7 ) are connected alternately by an analog multiplexer (204) to an analog-to-digital (A/D) converter (206). The A/D converter comprises an integrated sigma-delta modulator circuit (206) which generates a digitized 1-bit signal representing the input signal voltage level for a control unit (30) irrespective of whether the input channel signal is digital or analog. By means of the invention all input voltage channels (I 1 -I 7 ) are made similar such that the input channels (I 1 -I 7 ) of the interface unit can receive an analog or digital signal irrespective of each other.</p> |
