FALCOM FOX Hardware Manual - page 21
FOX H
ARDWARE
M
ANUAL
- P
RELIMINARY
-
V
ERSION
1.0.0
6.1.2 Special pin description (Pins 4, 5, 6)
All these pins are controlled by the internal firmware. All of them can be configured
for used either as analog or digital input or digital output. Some examples how to
use them are given in sections below
.
For IO lines that can work as input or output the corresponding output of this pin
has to be set to high (with PFAL command “
$PFAL,IO4
[5,6]
.Set=high”
), otherwise 0V
will be measured
(and the device could be damaged).
6.1.2.1
How to use these pins as analog inputs
Because these pins can operate either as digital or analog inputs, they have to be
configured and calibrated with the help of PFAL commands supported by the
firmware before using as analog inputs.
Analog voltages of up to 35.0 V with a 10 bits resolution can be processed and
remotely evaluated by a server application. Pull-up resistor to a constant input
voltage allows for resistive transducers to ground, e.g. fuel sensor or thermistors.
To use these IOs as analog inputs, the following configuration is required in the
software.
PFAL,IO
0[1,2]
.Config=AI,2,11
where 0, 1 and 2 are indices corresponding to IO1 (pin 4), IO2 (pin 5) and IO3 (pin 6)
respectively. While the value 2 and 11 are min. and max. voltages that will be used to
generate Low and High events, respectively. Detailed information can be found in
software manual “steppIII_fox_bolero_lt_PFAL_Configuration_Command_Set.pdf“
.
↓
Connection example 1 (for I/O1 and I/O2):
Thus, an analog input can be connected to a temperature sensor (a NTC
resistor for instance). In the diagram below, it is used a fixed resistor from the
input voltage to the I/O 2, and a variable resistor (
Negative Temperature Coefficient
- whose resistance or capacitance decreases when temperature increases
) to ground. It is
possible to set a low temperature alarm and a high temperature alarm
(upper and lower values), passed to required temperature. Passage through
these thresholds will trigger an alarm. We recommend to use SMS or TCP as
alarm type with GPIOP as attachment protocol. The SMS can be received
on a mobile phone, modem or any GSM device when changes are notified.
The analog-to-digital converter (ADC) inside the unit has an input voltage
range from 0 to 2.5 V. An application example is shown in figure below:
Figure 4:
Connection example 1 when using it as analog input.
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