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Connector pinouts, Digital input devices – Sierra Wireless MP 875 User Manual

Page 44

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MP 875 Modem User Guide

Note: No more than 36 VDC
should be applied to any I/O
pins.

Before using the digital input/output lines, you must configure
them as inputs or outputs.

Connector pinouts

The MP modem’s I/O port is a female DB15HD connector with
eight active I/O pins:

Two (2) digital I/O pins.

Two (2) digital input pins.

Four (4) analog input pins.

There are also six reserved pins and one ground pin.

1

5

6

10

11

15

DB15HD male cable

DB15HD female connector
on rear of MP modem

1.

Reserved—do not connect

2.

Reserved—do not connect

3. Digital Input/Output 1

4. Digital input 3

5.

Reserved—do not connect

6.

Reserved—do not connect

7. Analog input 2

8. Analog input 4

9.

Reserved—do not connect

10. Ground (GND)

11. Digital Input/Output 2

12. Digital input 4

13.

Reserved—do not connect

14. Analog input 1

15. Analog input 3

Figure 4-1: Pinouts for a male DB15HD I/O cable (left) that connects to the MP
modem’s female DB15HD I/O connector (right). Note that the two figures’
pinouts are mirror images of each other, since they plug into one another.

Port specifications

See

“I/O port characteristics”

on page 62 for the technical

specifications of the I/O ports, including input voltages.

Digital input devices

Digital input devices are those that have only two states and
send a signal to the MP modem in one of those states. An
example of a digital input device might be a gun rack alarm
that sends a signal to the MP modem any time the gun rack is
open. Another example would be a panic button that sends a
signal to the MP modem when it is pushed.

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