Measurement Specialties PMD-1024HLS manual False

PMD-1024HLS User's Guide					Functional Details
Pull-down	Pull-down	Pull-down
CTR GND GND GND GND Port A Pull-up /	USB +5 V Port B Pull-up /	GND Port C Pull-up / USB +5 V GND Port C7		Port C6	Port C5 Port C4 Port C3 Port C2 Port C1 Port C0
20 19 18 17 16 15	14 13	12 11	10 9 8	7	6 5 4 3 2 1

Port A0 21

Port A1 22

Port A2 23

Port A3 24

Port A4 25

Port A5 26

Port A6 27

Port A7 28

GND 29

USB +5 V 30

GND 31

Port B0 32

Port B1 33

Port B2 34

Port B3 35

Port B4 36

Port B5 37

Port B6 38

Port B7 39

GND 40

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 3-2for the location of these pins. You can configure each digital port for either input or output.

When configured for input, you can use the PMD-1024HLS digital I/O terminals to detect the state of any TTL level input. Refer to the switch shown in Figure 3-3and the schematic shown in Figure 3-4.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.

Figure 3-3. Digital connection of Port A0 detecting the state of a switch

3-3