AirLink LX40 Series Hardware User Guide
Rev. 2 January 2021
28
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Figure 2-15: Analog Input
Data sampling is handled by a dedicated microprocessor. In order to filter noisy signals,
twenty measurements are taken over a 250 ms interval. The measurements are averaged
to generate a sample. If the change since the last sample is significant, a notification is
sent to the CPU for updating the current value displayed in the user interface and for use
by Events Reporting.
Changes are considered significant if the change is 200 mV or more (when the range of
monitored voltage is 0–5 V) or 350 mV or more (when the range of monitored voltage is
0–10 V). If there has not been a significant change to the parameter being monitored, the
CPU reads a sample every 2.5 minutes, which detects small changes.
Figure 2-16: Analog Input Sampling and Reading
Note: The same method is used to sample the input voltage and the internal board temperature for
Events Reporting. The significant changes are 300 mV for the input voltage and 1 ºC for the board
temperature.
LX40
V
in
Internal pull-up
resistor
Off (default)*
Z
in
!Nſ
Protection
Circuitry
Pin 4 (power connector)
Solar panel or battery
Output Off (default)*
+
–
* Configurable on the ACEmanager I/O tab
Table 2-6: Analog Input
Pull-up
Minimum
Typical
Maximum
Off
Analog Input Range
0.5 V
—
5 V, 10 V
(configurable)
Analog Input Accuracy
-1.5%
0.50%
1.5%
Microprocessor
CPU
Sample every 250 ms,
Reading from the CPU
Updates UI
Events Reporting
When a reading is received,
based on 20 measurements
when change is significant
or 2.5 minutes has passed
with no change
Pin 4 on the power connector
Analog input
