Installation and Startup
Rev 4 Nov.16
25
4119008
Data sampling is handled by a dedicated microprocessor. In order to filter noisy
signals, twenty measurements are taken over a 250 ms interval and they 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 150 mV or more. 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 2-14: 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 m V for the input
voltage and 1 degree Celsius for the board temperature.
Low Side Current Sink Output
Low side current sink output, for example to drive a relay, is only available using
Pin 4 on the power connector.
Figure 2-15: Low Side Current Sink
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 or
Analog input
Pin 6 or 7 on the auxiliary I/O connector
MP70 router
Off
Pin 4 on the power connector
External Solenoid/
Relay circuit
Vin
Protection
circuitry
V
in
I
Sink
= 500 mA (Typical)
*
* See
on page 26 for more details.
Internal Pull-up
Resistor
