Campbell Scientific HMP155A Temperature and Relative Humidity Probe - Manual (Page 38)

Appendix C. Interfacing with HMP155A RS-485 Output
‘CR1000 Series Datalogger
‘Sensor Wiring:
‘HMP155A with RS-485 Output:
‘
‘ HMP155A
HMP155A SDM-SIO1 CR1000 Connector Pin-Out
‘ CSI Vaisala
‘ *Cable Cable
‘ blue
pink Y 6
‘ yellow brown Z 2
‘ black red G 8
‘ red blue 12V 7
‘ white green 0V 3
‘ shield (clear) black Ground not connected
‘ grey, pink, brown – NOT used
‘ *HMP155ACBL2 cable, ordered separately
‘Declare Public Variables
Public TempC, RH, NbytesReturned
Public SerialIndest As String * 26
Public String_1 As String
Public String_2 As String
Const SensorPort=32
Const CRLF=CHR(13)+CHR(10)
SequentialMode
‘Define Data Tables
DataTable (Table1,1,-1)
DataInterval (0,15,Min,10)
Average (1,TempC,FP2,False)
Sample (1,RH,FP2)
EndTable
‘Main Program (for sensor configured for default settings of 4800 baud, E,7,1)
BeginProg
SerialOpen (SensorPort,4800,58,0,53)
‘ buffer = 2*number of bytes + 1
‘ SDM-SI01 port 58 for half duplex,7,E,1
‘Strings to start serial output
String_1 = “SMODE RUN”+CRLF
‘ set SMODE to “RUN”
String_2 = “R”+CRLF ‘ send “R” to start serial output
‘Instructions to enable RS-485 serial output
SerialOut (SensorPort,String_1,”RUN”,3,100) ‘send String_1, wait for ‘RUN’ response
Delay (0,500,mSec)
SerialOut (SensorPort,String_2,”RH”,3,100) ‘send String_2
Scan (5,Sec,0,0)
‘Get serial string from sensor
SerialInRecord (SensorPort,SerialIndest,00,24,&H0D0A,NbytesReturned,00) ‘&H0D0A = CRLF
‘Parse RH and temp from string
RH=Mid (SerialIndest,5,4)
SplitStr (RHArray(1),SerialIndest,”=”,2,0)
CallTable Table1
NextScan
EndProg
C-2