Campbell Scientific

Logging the ASP with a Campbell Scientific Data Logger

Compatibility

The following Campbell Scientific data loggers have native RS485 ports:

Model	No. RS485 Ports	Ports
CR350	2	Com2 (Tx/Rx)Com3 (Tx/Rx)
CR6	2	ComC1 (C1/C2)ComC3 (C3/C4)
CR1000Xe	4	ComC1 (C1/C2)ComC3 (C3/C4)ComC5 (C5/C6)ComC7 (C7/C8)

For models without an integrated RS485 port an RS485 interface is required. Talk with your local Campbell Scientific dealer to discuss options.

CR350

The CR350 can control up to two ASP array's natively, or up to 16 with an AM16/32 multiplexor. It measures each ASP sequentially, so is not suitable for applications where strict timing or syncronised sampling is required. For applications where measurements can be within a few seconds / minutes of nominal sample time, it is a cost effective approach.

Logger Wiring

The CR350 will need power via it's Bat port, and can be directly communicated with via the USB C interface for software updates and data downloads.

CR350	Connection	Function
Bat +	12V DC	12V DC Power In
Bat -	DC Gnd	DC Ground
USB C	PC via USB C	PC Connection to Logger Net / PC400

CR350 to AM16/32 - Multiplexer Control & Power

The following handles the power to the multiplexer and the control lines that tell it when to switch channels.

CR350 Terminal	AM16/32 Terminal	Function
12V	12V	Main Power for the Mux
C1	RES	Reset (Turns Mux On/Off)
C2	CLK	Clock (Advances to next channel)
G	GND (Control side)	Control Ground

CR350 to AM16/32 - ASP Common Power and Data Lines

The ASP's communicates via ModbusRTU over half duplex RS-485, requiring two data wires (A and B).

Each ASP is powered by a 12V DC Supply from the CR350.

CR350 Terminal	AM16/32 Common Terminal	Function
COM2 Rx	COM ODD H	RS485 - A
COM2 Tx	COM ODD L	RS485 - B
COM1 12v	COM EVEN H	ASP 12V
COM1 G	COM EVEN L	ASP Ground

AM16/32 to Osprey ASPs - Sensor Array Wiring

Each ASP needs to be connected to one of the 4 wires ports of the AM16/32.

Make sure your AM16/32 mode switch is physically flipped to4x16**.

AM16/32	ASP Wire	Function
ODD H	Blue	RS485 - A
ODD L	White	RS485 - B
EVEN H	Red	ASP 12V
EVEN L	Black	ASP Ground

Further ASP's can be added on each of the 4 wire ports.

Software

The following software example will read ASPs connected to each 4 wire port of the AM16/32 in turn.

It requires the following parameters to be set by the user:

Define mux channels to be used. Total number of connected ASPs.
The maximum number of sensors on any array, including reference sensor.
The name and number of sensors on each channel.

' -------------------------------------------------------------------------
' CR350 Reference Code for Osprey ASP Sensor Array
' Multiplexer: AM16/32 (4x16 Mode) - Multi-Channel Support
' -------------------------------------------------------------------------

' Define Logger Terminals
Const MuxRES = C1       
Const MuxCLK = C2       
Const ModbusPort = Com2 ' Matches the physical COM2 Rx/Tx terminals

' =========================================================================
' USER CONFIGURATION
' =========================================================================
' 1. Define Multiplexer Channels (Max 16 in 4x16 mode)
Const NUM_CHANNELS = 4 

' 2. Define the max number of sensors on ANY single channel
' (Required to allocate logger memory. Set high enough for your largest array)
Const MAX_SENSORS = 11

' Configuration arrays (Editable live via LoggerNet/PC400)
Public SensorCount(NUM_CHANNELS) As Long
Public ArrayName(NUM_CHANNELS) As String * 20

' Declare State Variables
Public PTemp As Float
Public batt_volt As Float
Public ch As Long        ' Mux Channel Index
Public i As Long         ' Sensor Index
Public MBResult As Long   

' Modbus Data Variables (2D Arrays: Channel, Sensor Index)
Public Distance(NUM_CHANNELS, MAX_SENSORS) As Float
Public Voltage(NUM_CHANNELS, MAX_SENSORS) As Float
Public Temperature(NUM_CHANNELS, MAX_SENSORS) As Float

' Define the Data Table
DataTable(OspreyData, True, -1)
  DataInterval(0, 5, Min, 10) ' Set to 5 minutes for testing
  
  ' Sample the names for reference
  Sample(NUM_CHANNELS, ArrayName(), String)
  
  ' Flattened 2D Arrays (Stores all channels & all max possible sensors)
  Sample(NUM_CHANNELS * MAX_SENSORS, Distance(), FP2)
  Sample(NUM_CHANNELS * MAX_SENSORS, Voltage(), FP2)
  Sample(NUM_CHANNELS * MAX_SENSORS, Temperature(), FP2)

EndTable

' -------------------------------------------------------------------------
' MEASUREMENT SUBROUTINE
' -------------------------------------------------------------------------
Sub ReadOspreyArray
  Dim WarmupDelay_mSec As Long
  
  ' 1. MULTIPLEXER CONTROL & POWER UP
  PortSet(MuxRES, 1) 
  Delay(0, 10, mSec)
  
  ' Loop through each defined multiplexer channel
  For ch = 1 To NUM_CHANNELS 
    
    ' Clock the multiplexer to advance to the next channel
    PortSet(MuxCLK, 1) 
    Delay(0, 10, mSec)
    PortSet(MuxCLK, 0) 
    
    ' Only execute if sensors are configured for this specific channel
    If SensorCount(ch) > 0 Then
      
      ' 2. SENSOR WARM-UP DELAY (Calculated dynamically per channel)
      WarmupDelay_mSec = 3500 + (350 * SensorCount(ch)) 
      Delay(0, WarmupDelay_mSec, mSec) 

      ' 3. MODBUS POLLING LOOP (Closest to Farthest)
      For i = 1 To SensorCount(ch) 
        ' --- RESET VARIABLES TO NAN ---
        Distance(ch, i) = NAN
        Voltage(ch, i) = NAN
        Temperature(ch, i) = NAN
        
          
        ' Using Logical addresses (Physical + 1)
        ModbusMaster(MBResult, ModbusPort, 9600, i, 3, Distance(ch, i), 257, 1, 1, 200, 2)
        Delay(0, 80, mSec)
        
        ModbusMaster(MBResult, ModbusPort, 9600, i, 3, Voltage(ch, i), 259, 2, 1, 200, 2)
        Delay(0, 40, mSec)
        
        ModbusMaster(MBResult, ModbusPort, 9600, i, 3, Temperature(ch, i), 261, 2, 1, 200, 2)
        Delay(0, 80, mSec)
        
        
        ' 4. NODE TRANSITION DELAY
        Delay(0, 120, mSec)
      Next i
      
    EndIf
  Next ch
  
  ' 5. SHUTDOWN ARRAY & POWER CYCLE
  PortSet(MuxRES, 0) 
EndSub

' -------------------------------------------------------------------------
' MAIN PROGRAM
' -------------------------------------------------------------------------
BeginProg
  ' Open COM port for Modbus
  SerialOpen(ModbusPort, 9600, 0, 0, 100, 4)

  ' =======================================================================
  ' INITIALIZE CHANNEL CONFIGURATIONS
  ' Define your array names and sensor counts here.
  ' Note: Unused channels can be set to 0. 
  ' =======================================================================
  ArrayName(1) = "South Culvert"
  SensorCount(1) = 9

  ArrayName(2) = "East Slope"
  SensorCount(2) = 11

  ArrayName(3) = "West Slope"
  SensorCount(3) = 11

  ArrayName(4) = "Northern Basin"
  SensorCount(4) = 7 

  ' =======================================================================
  ' RUN ON STARTUP / POWER CYCLE
  ' =======================================================================
  ' Populates the Public variables immediately on boot for live monitoring
  Call ReadOspreyArray

  ' =======================================================================
  ' RUN ON SCHEDULED INTERVAL
  ' =======================================================================
  Scan(5, Min, 0, 0)
    ' Read internal logger health
    PanelTemp(PTemp, 60)
    Battery(batt_volt)

    ' Call the measurement sequence
    Call ReadOspreyArray
    
    ' Save the data to memory
    CallTable(OspreyData)
  NextScan
EndProg

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