LoRa Node
17
Connect to devices via AIs (Analog Input) :
The IOT400 provides 3 AI ports for connecting to those analog sensor/meters. To connect the external devices,
you have to identify the type of your device and properly connect and configure the IOT400 so that it can get
the correct readings from the connected devices.
The AI port supports either 0-10V voltage mode, or 4-20mA current mode analog signal. Since the IOT400 can
not detect what kind of device is connected to, not only hardware configuration (
CON4
,
CON5
) is required, but
also software configuration is mandatory.
CON4
is dedicated for AI configuration. There are 3 sets of jumper headers, one for each AI port (AI1, AI2, AI3).
Without Jumper :
0-10V Voltage mode -
(factory default)
With Jumper :
4-20mA Current mode -
(You have to put the Jumper manually)
Pinout Definition @ CON5
Pin1*
Pin2
Pin3
Pin4
Pin5
Pin6
Pin7
Pin8
3.6Vout1
GND
AI1+
AI1-
AI2+
AI2-
AI3+
AI3-
Note
: 3.6Vout1 @ CON5.1 is only valid when external power source is applied. It is disabled for Battery power
source.
Analog Input Specification
Mode
Specification
Range
Precision
Voltage Mode
0-10V
+/- 10mV
Current Mode
4-20mA
+/- 20
μ
A
The IOT400 is designed with 12-bit ADCs (Analog-to-Digital Converter), considering hardware scaling and 0.1%
resistance variation effects, the overall precision for the 0-10V is /-10mV.
If the signal range of your device will run out off the design spec. of IOT400 (0-10V or 4-20mA), you have to
add a certain scaling circuit to prevent overflow readings and even damage the IOT400.