Campbell CR800 Series, Operator'S Manual

Page: 191 / 598

Section 7. Installation
191
7.7.5 Data Output: Two Intervals in One Data Table
Two Data-Output Intervals in One Data Table
'This program example demonstrates the use of two time intervals in a data table. One time
'interval in a data table is the norm, but some applications require two.
'
'Allocate memory to a data table with two time intervals as is done with a conditional table,
'that is, rather than auto-allocate, set a fixed number of records.
'Declare Public Variables
Public PTemp, batt_volt, airtempC, deltaT
Public int_fast As Boolean
Public int_slow As Boolean
Public counter(4) As Long
'Declare Data Table
'
'Table is output on one of two intervals, depending on condition.
'Note the parenthesis around the TriggerVariable AND statements.
DataTable (TwoInt,(int_fast AND TimeIntoInterval (0,5,Sec)) OR (int_slow AND _
TimeIntoInterval (0,15,sec)),15000)
Minimum (1,batt_volt,FP2,0,False)
Sample (1,PTemp,FP2)
Maximum (1,counter(1),Long,False,False)
Minimum (1,counter(1),Long,False,False)
Maximum (1,deltaT,FP2,False,False)
Minimum (1,deltaT,FP2,False,False)
Average (1,deltaT,IEEE4,false)
EndTable
'Main Program
BeginProg
Scan (1,Sec,0,0)
PanelTemp (PTemp,250)
Battery (Batt_volt)
counter(1) = counter(1) + 1
'Measure thermocouple
TCDiff (AirTempC,1,mV2_5C,1,TypeT,PTemp,True,0,250,1.0,0)
'calculate the difference in air temperature and panel temperature
deltaT = airtempC - PTemp
'When the difference in air temperatures is >=3 turn LED on and trigger the faster of
'the two data-table intervals.
If deltaT >= 3 Then
PortSet (4,true)
int_fast = true
int_slow = false
Else
PortSet (4,false)
int_fast = false
int_slow = true
EndIf