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P a g e
4.6
Configurable Digital I/O
The Layer N SP-016 features 2 configurable digital I/O pins. These can be used for a myriad of applications including driving
relays, physical alarms, or sensing dry contacts like door switches.
4.6.1
Input Settings
To use a pin as an input, make sure it is set to Active Low (default) in the
Output Tab
in SYNC.
Each pin has an internal pull-up, but in order to save power, the internal pull-up is only active when the unit takes a
reading. Refer to the following table to decode the input state.
Input 1
Input 0
Reading
Inactive
Inactive
0
Inactive
Active
1
Active
Inactive
2
Active
Active
3
4.6.2
Output Settings
To use a pin as an output, configure the outputs setting in the
Output Tab
and assign the output to an alarm using
SYNC. For more information on how to set an alarm, refer to section
4.6.3 Setting Alarms
.
Output options are set in the Output Tab of SYNC. Each output can be configured as either Active High or Active
Low. When configured as Active High the output conducts normally and becomes high impedance when activated.
When
configured as Active Low the Open Drain output is high impedance normally and will conduct when activated. It is
recommended to change the input type to match the output type so that the output state will be correctly
represented in
logs.
Pin
Name
Function
Pin 1
DIO 0
Discrete I/O Signal 0
Pin 2
INTR
Interrupt Signal
Pin 3
SCL
I2C Clock Signal
Pin 4
SDA
I2C Data Signal
Pin 5
Shield
Shield Ground
Pin 6
DIO 1
Discrete I/O Signal 1
Pin 7
GND
Power Ground
Pin 8
3.3VDD
Power Supply
M12 8-Pin Connector
