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Hi fellow Campbell users!

I recently installed a Vaisala HMT110T (model code R0C03A0) temperature sensor with RS485 output in to a CR1000X datalogger. The sensor is mounted at 80m height on a wind monitoring mast. I used a good quality twisted pair, shielded cable.

I am logging the average, standard deviation, maximum, and minium temperature values in a 10-minute data table, with a 1 second sample frequency.

There are lots of NAN values appearing in the maximum and minimum columns. I am also getting spurious values in the average data column when the data is compared to readings from a secondary Vaisala HMP110 temp / RH sensor (analouge output) mounted at 2m height.

Below are the aplicable sections of the datalogger program. Can anyone please advise how to avoid getting the NAN values in the max and min data, and also why the average temperatue data sometimes gives spurious negative values (e.g. HMT110T records -7.86 and HMP110 records 4.35 degrees)?

On a separate note, there also seems to be an issue at power up of the logger or when a new program is sent to the logger. The logger real-time values do not update (all stay on zero, even the record number) until the HMT110T sensor is disconnected. When I then reconnected the HMT110T sensor, the logger starts working and record numbers increment. This means I cannot update the program remotely via our cellular modem.

Any help here would be greatly appreciated.

Thanks,

Matt

'CR1000X Series Datalogger

'====================================================================
' MEASUREMENTS
' Temperature at 80m (Vaisala HMP110T w/RS485 Output)
' Temperature & Relative Humidity at 2m (Vaisala HMP155 w/Analogue Output)
' -------------------------------------------------------------------

'Declare Constants
Const Tower = "Mast"
Const FileName = "CRD:"+Tower+"_"

'Declare Public Variables
Public T2 'Vaisala HMP110 at 2m
Public RH2 'Vaisala HMP110 at 2m

'Vaisala HMT110T at 80m
Public NBytesReturned As Long
Public TempString As String * 8
Public T80 As String * 4
Public String_1 As String
Public String_2 As String
Const CRLF=CHR(13)+CHR(10)

SequentialMode

'Declare Units
Units T80(1) = Deg_C
Units T2 = Deg_C
Units RH2 = %


'Define Data Tables
DataTable (Tower,1,-1)
  DataInterval (0,10,Min,10)
  TableFile (FileName,8,-1,0,1,Day,0,0)

  'Temperature T80 @ 80m
  Average (1,T80,FP2,False)
  StdDev (1,T80,FP2,False)
  Maximum (1,T80,FP2,False,False)
  Minimum (1,T80,FP2,False,False)

  'Temperature T2 @ 2m
  Average (1,T2,FP2,False)
  StdDev (1,T2,FP2,False)
  Maximum (1,T2,FP2,False,False)
  Minimum (1,T2,FP2,False,False)

  'Relative Humidity RH2 @ 2m
  Average (1,RH2,FP2,False)
  StdDev (1,RH2,FP2,False)
  Maximum (1,RH2,FP2,False,False)
  Minimum (1,RH2,FP2,False,False)

EndTable


'Main Program
BeginProg

  'Configure Com7 as RS485 Port for HMP110T configured for 19200 baud, N,8,1)
  SerialOpen (ComC7,19200,0,0,53,4) ' buffer = 2*number of bytes + 1

  'Define Strings to start serial output from HMT110T
  String_1 = "SMODE RUN"+CRLF ' set SMODE to "RUN"
  String_2 = "R"+CRLF ' send "R" to start serial output

  'Instructions to send to enable RS485 to enable serial output
  SerialOut (ComC7,String_1,"RUN",3,100) 'send String_1, wait for 'RUN' response
  Delay (0,500,mSec)
  SerialOut (ComC7,String_2,"T",3,100) 'send String_2

  Scan (1,Sec,3,0)

    'Get serial string from the 80m HMT110T Temperature Sensor
    SerialInRecord (ComC7,TempString,00,8,&H0D0A,NBytesReturned,01) '&H0D0A = CRLF
    'Parse Temp from string
    SplitStr (T80,TempString,"=",1,0)

    'Measure the 2m Temperature & Relative Humidity Sensor
    'Temperature Measurement -80 to +60 deg
    VoltSe (T2,1,mV1000,3,1,0,50,0.14,-80)
    'Relative humidity Measurement
    VoltSe (RH2,1,mV1000,4,1,0,50,0.1,0)

    'Call Output Tables
    CallTable Tower

  NextScan

EndProg

Hi all, Just wondering if anyone could please help with the above? Thanks! Matt