Campbell Scientific HC2S3 Temperature and Relative Humidity Probe User Manual

Page 38

Appendix C. HC2S3 Digital Communications

Sensor Wiring:
E2-05XX-MOD

Cable

MD485

CR1000

Blue

Red

Green

12V

Gray/Yellow

Clear

Ground Symbol

If the Rotronic cable includes brown and white wires (voltage
signals for temperature and humidity), CSI recommends
“capping” them with PN 27749 or equivalent insulated caps to
prevent the possibility of shorting.

NOTE

Connect the CS I/O port of MD485 to CS I/O port on CR1000 with an SC12
cable.

The following example CR1000 program configures the CS I/O port as
COMSDC7 using the SerialOpen instruction, sends the RDD (Read Values)
command “|{F00RDD}CR” to the probe, and parses temperature and relative
humidity values from the data string returned by the probe.

Example CR1000 Program:

'CR1000 Program
'Declare variables

Public SerialIndest As String * 100
Dim String_1 As String
Const CRLF=CHR(13)+CHR(10)

Dim HC2S3_Split(17) As String * 40
Alias HC2S3_Split(2) = RH_Str

'RH string.

Alias HC2S3_Split(6) = TempC_Str

'Temp string.

Alias HC2S3_Split(17) = HC2S3_SN_Str

'HC2S3 serial number string.

Public TempC, RH, NBytesReturned

DataTable (Table1,1,-1)
DataInterval (0,15,Min,10)
Average (1,TempC,FP2,False)

Sample (1,RH,FP2)
EndTable

BeginProg
SerialOpen (ComSDC7,19200,0,0,100)

'Configure CS I/O port

String_1 = "|{F00RDD}"+CRLF

'RS485 command to send data

Scan (5,Sec,0,0)

SerialFlush (34)
SerialOut (ComSDC7,String_1,0,2,100)

'Send command to send data

Delay (0,500,mSec)

'Get data from probe
SerialInRecord (ComSDC7,SerialIndest,&H6464,0,&H3B48,NBytesReturned,01)

'Parse RH and temp from string
SplitStr (HC2S3_Split(),SerialIndest,";",17,7)
RH=RH_Str

TempC=TempC_Str

CallTable Table1

NextScan
EndProg

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