¶ Overview
The Automated Monitoring Nodes (AMN) can accept third-party sensors that output current such as 4-20mA. Additionally, the AMN-PLUS has two discrete analog inputs that can accept current sensors as well.
¶ Getting Started
¶ Installation
A current sensor typically consists of a two-wire output. There are a few exceptions, where the power to the sensor is separated and this will be described below as well.
- Determine what wires output the value in current (mA) from the sensor
- Most sensors will have two wires or three wires, identify the wire and purpose and note the polarity of each wire
- Using the table below, connect the wires to the desired sensor port and power port
- Finally, connect a jumper to the corresponding port as shown in the table and photos below
¶ Current Sensor Wiring
2-Wire:
| Sensor Wire Name | Purpose | nM Port |
| “Signal” or "Output" or "Return" or “GROUND” (Typically Black Wire) | Output the sensor status in mA | Any GPIO (All Units) or A1/A2 ports (AMN-PLUS only) |
| "Power +" or "Supply V+" or “VCC” or “VDC+” (Typically Red Wire) | Provides power to sensor (make sure to connect to the power specified by the sensor manufacturer). | +12v or +5v Power |
3-Wire:
| Sensor Wire Name | Purpose | nM Port |
| "Signal" or "Output" | Output the sensor status in mA | Any GPIO (All Units) or A1/A2 ports (AMN-PLUS only) |
| GND | Ground | GND |
| "Power +" or "Supply V+" (Typically Red Wire) | Provides power to sensor (make sure to connect to the power specified by the sensor manufacturer). | +12v or +5v Power |
¶ AMN-PLUS Jumper Configurator
 |
| Insert the jumper into the corresponding position as detailed in the table below (this is the port that the signal/output wire is landed on). As shown is the GPIO3 for the AMN-PLUS |
 |
| Locate the jumper block on the edge of the board. Use the table below to determine which set of pins to place the jumper |
Note: Ignore far-right jumpers, they are used to configure the counter (e.g. Rain Gauge or Flow Meter).
| A2 | A1 | GPIO4 | GPIO3 | GPIO2 | GPIO1 | ||
| A2 | A1 | GPIO4 | GPIO3 | GPIO2 | GPIO1 |
¶ Configuration
¶ Get Prompt
First, you will need to open a serial terminal to the AMN and arrive at the NeatMon Main Menu. If you are unsure how to do this check the Opening Serial Terminal guide.
NeatMon Main Menu
1: Network config
2: Sensor config
3: Utilities
x: < Save & Quit
>Choose Sensor config by pressing 2.
¶ Select sensor
Sensor Config
1: Add sensor
2: Disable Battery monitor
3: List sensors
4: Delete sensor
5: Test read
x: <Back
>Choose Add sensor by pressing 1.
Create sensor
Select type:
1: nM TPRH sensor
2: nM NCTP sensor
3: nM GPIO analog (4v max)
4: nM digital counter
5: nM air quality monitor
6: Generic SDI-12 Sensor (M)
7: Sentek RS485 SM
8: LeafMon sensor
x: <Back
>Choose either nM GPIO analog or A1/A2 analog depending on the unit type that will be connected. For our example we will follow setup for the GPIO, however the A1/A2 setup for the AMN-PLUS is similar.
¶ Configure Sensor
¶ Add sensor
Create sensor
Select type:
1: nM TPRH sensor
2: nM NCTP sensor
3: nM GPIO analog (4v max)
4: nM digital counter
5: nM air quality monitor
6: Generic SDI-12 Sensor (M)
7: Sentek RS485 SM
8: LeafMon sensor
9: Next page....
x: <Back
>3Choose the nM GPIO analog or A1/A2 sensor type to begin configuring a new sensor (for our example we will follow the GPIO setup, although they are both similar)
¶ Configure sample time
Enter sample rate (mins): 15
¶ Configure/Select port
Enter GPIO port (1-4):
>1
¶ Configure scaling
Determine if the scaling/calibration will reside on the AMN or will be calibrated in software at a later time. An advantage to calibrating in software later is that the analog value is retained and can be useful for debugging.
For an example on calibration formulas please see this calibration worksheet
In the example below, a calibration of 100X+1 has been entered.
Use scaling (M(X) + B)? (Y/n)
>Y
Enter value (float) for M: 100
Enter value (float) for B: 1
Will use scaling: F(X)=100.00X+1.00
Values okay? (Y/n)
>Y
¶ Configure custom name
It is possible to provide a custom name to ‘tag’ data sent to the API. It is useful to know what sensor is connected. Provide a 3 character name
Change sensor name (av1)? (Y/n)
>Y
Enter new name (max 3 chars): psi
Set name¶ Configure excitation
Excitation of 1000mS is typical. Please refer to the sensor manufacturer for specifications or contact support for guidance
Enter excitation time in milliseconds (0 to ignore)
>1000
Excitation time: 1000ms. Is this correct? (Y/n)¶ Save Configuration
Once saved, the custom name if entered will be displayed, and it is possible to test read the sensor to get the converted and RAW values, by selecting option 5 and selecting the sensor to interrogate
Created psi
Sensor Config
1: Add sensor
2: Enable Battery monitor
3: List sensors
4: Delete sensor
5: Test read sensors
x: <Back
>Choose <Back by pressing x.
Created psi
Sensor Config
1: Add sensor
2: Enable Battery monitor
3: List sensors
4: Delete sensor
5: Test read sensors
x: <Back
>x
Exiting...
neatMon Main Menu
1: Network config
2: Sensor config
3: Utilities
x: < Save & Quit
>Choose Save & Quit by pressing x again.
NOTE: If you don't do this the sensor will not be saved.
¶ Sample Sensor
First, you must open a serial terminal to the AMN and arrive at the NeatMon Main Menu. If you're unsure how to do this check the Opening Serial Terminal guide.
NeatMon Main Menu
1: Network config
2: Sensor config
3: Utilities
x: < Save & Quit
>Choose Sensor config by pressing 2.
Sensor Config
1: Add sensor
2: Disable Battery monitor
3: List sensors
4: Delete sensor
5: Test read
x: <Back
>Choose Test read by pressing 5.
0. Battery monitor
1. psi:
Type: av [1]
Sample rate (mins): 15
Interface: Analog voltage
Port: 1
Misc:
Using: millivolts
M: 100.00
B: 1.00
Excitation time: 1000ms
Enter index of sensor to read (x to cancel):Type the number related to the sensor just added.
It will now read the sensor and output the sensor data. Validate data If necessary by changing the sensor accordingly, for example apply pressure to a pressure gauge.