B&B Electronics 48/24-Channel Digital Input/Output USB Module USB-4751/4751L Benutzerhandbuch
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Chapter 3
3.3 Digital I/O Connections
3.3.1 Dry Contact Support for Digital Input
Each digital input channel accepts either dry contact or 0 ~ 5 VDC wet
contact inputs. Dry contact capability allows the channel to respond to
changes in external circuitry (e.g., the closing of a switch in the external
circuitry) when no voltage is present in the external circuit. Figure 3-3
shows external circuitry with both wet and dry contact components, con-
nected as an input source to one of the card's digital input channels.
contact inputs. Dry contact capability allows the channel to respond to
changes in external circuitry (e.g., the closing of a switch in the external
circuitry) when no voltage is present in the external circuit. Figure 3-3
shows external circuitry with both wet and dry contact components, con-
nected as an input source to one of the card's digital input channels.
Figure 3.3: Digital Input Connections