Campbell Scientific CR1000 Measurement and Control System - Manual (Page 431)

Section 10. Troubleshooting
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CRBasic Example 69. Using NAN to Filter Data
'Declare Variables and Units
Public TC_RefC
Public TC_TempC
Public DisVar As Boolean
'Define Data Tables
DataTable (TempC_Data,True,-1)
DataInterval (0,30,Sec,10)
Average (1,TC_TempC,FP2,DisVar) 'Output process
EndTable
'Main Program
BeginProg
Scan (1,Sec,1,0)
'Measure Thermocouple Reference Temperature
PanelTemp (TC_RefC,250)
'Measure Thermocouple Temperature
TCDiff (TC_TempC,1,mV20,1,TypeT,TC_RefC,True,0,250,1.0,0)
'DisVar Filter
If TC_TempC = NAN Then
DisVar = True
Else
DisVar = False
EndIf
'Call Data Tables and Store Data
CallTable (TempC_Data)
NextScan
EndProg
10.4 Communications
10.4.1 RS-232
Baud rate mis-match between the CR1000 and datalogger support software is
often the root of communication problems through the RS-232 port. By default,
the CR1000 attempts to adjust its baud rate to that of the software. However,
settings changed in the CR1000 to accommodate a specific RS-232 device, such
as a smart sensor, display or modem, may confine the RS-232 port to a single
baud rate. If the baud rate can be guessed at and entered into support software
parameters, communications may be established. Once communications is
established, CR1000 baud rate settings can be changed. Clues as to what the baud
rate may be set at can be found by analyzing current and previous CR1000
programs for the SerialOpen() instruction; SerialOpen() specifies a baud rate.
Documentation provided by the manufacturer of the previous RS-232 device may
also hint at the baud rate.