Measurement Computing USB-1024HLS - Manual (Page 13)

USB-1024HLS User's Guide Functional Details
20
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1
Digital I/O terminals (Port A0 to A7, Port B0 to B7, Port C0 to C7)
Connect up to 24 digital I/O lines to the screw terminal containing pins 1 to 8 ( Port C0 to Port C7 ), pins 21 to
28 ( Port A0 to Port A7 ), and pins 32 to 39 ( Port B0 to Port B7 ). Refer to the pinout diagram on page 3-2 for the
location of these pins. You can configure each digital port for either input or output.
When configured for input, you can use the USB-1024HLS digital I/O terminals to detect the state of any TTL
level input. Refer to the switch shown in Fi
and the schematic shown in . If you set the
switch to the +5 V input, Port A0 reads TRUE (1). If you move the switch to GND, Port A0 reads FALSE.
gure 3-3
Figure 3-3. Digital connection of Port A0 detecting the state of a switch
Figure 3-4
3-3