12 |
M 5 7 7 9
5.3.3
Discrete Input/Output (DIO)
The Layer N SP-006 features 2 configurable discrete I/O pins DIO_0 and DIO_1. These DIO pins can be used
for a myriad of applications including driving relays, physical alarms, or sensing dry contacts like door
switches. The user may configure the polarity of the inputs (active
HIGH
or active
LOW
) or
Disable
the DIO to
utilize the outputs (ON/OFF, PWM, SERVO). The Advanced Scaling option does not apply to the DIO input
reading.
Figure 10: SYNC interface discrete I/O input configuration
The Discrete I/O input shares the same circuitry as the output. The internal process drives the output control
signal to turn on the output driver which will force the output low. When the state of the DIO input signal is
to be read the processor applies 3.3 V
DC
to the Input Bias signal and reads the level detected at the Input
Sense. If the output is inactive an external signal may be used to force the input level low. A diode protects
external positive voltages, allowing the output driver to activate loads greater than the internal 3.3 V
DC
.
5.3.3.1
Setting DIO as an Input
To use a DIO pin as an input, make sure it is set to
Active Low
(default) in the
Output Tab
in SYNC.
Then, in the
Input Tab
, select a
Type
from the drop-down which includes DIO. Each DIO pin has an
internal pull-up, but to save power, the internal pull-up is only active when the unit takes a reading.
Figure 11: Discrete I/O circuitry
Figure 12: SYNC interface outputs tab
