Sierra Wireless 20070914 - Manual (Page 66)

PinPoint X HSDPA
53 20070914
Digital Inputs
Figure 7-2: Digital Input Contact Closure
By measuring contact closures on switches, the digital inputs
can report a simple open or closed state. Each of the four
digital inputs can be wired to the two ground signals via a
switch. When the switch is open, the input will read “OPEN”.
When the switch is closed and the input is connected to
ground, the input will read “CLOSED”.
• When a door or other latch is opened or closed.
• Counting pulses or other electronic events.
• When a gauge reaches a certain point.
• When a container fills or empties.
• When a switch or valve is opened or closed.
• When the tow bar is raised or lowered.
• Connected to a sensor, the level of fuel in a vehicle.
• When the trunk of a vehicle is opened or closed.
• When the ignition is turned on or off.
Relay Outputs
As an electronic switch which can be opened or closed
(Normally Open relay), a relay can be used to transmit an
action to another device by signalling to that other device an
“on” or “off”. As a Normally Open relay, the circuit of the
relay is disconnected (open) unless it is active. When the relay
is active, the circuit is connected (closed).
• Setting off an alarm or siren.
• Triggering a process to start on another device.
• Opening or closing a valve or switch.
• Locking or unlocking a door.
• Turning a light on or off.
• Opening the vehicle’s trunk or doors.