Campbell Scientific CR1000KD CR800 and CR850 Measurement and Control Systems - Page 253

Section 7. Installation 'Declare Units Units PTemp_C = deg C Units AirTemp_C = deg C Units DeltaT_C = deg C 'Declare Output Table -- Output Conditional on Delta T >=3 'Table stores data at the Scan rate (once per second) when condition met 'because DataInterval instruction is not included in table declaration. DataTable(DeltaT,DeltaT_C >= 3,-1) Sample(1,Status.StationName,String) Sample(1,DeltaT_C,FP2) Sample(1,PTemp_C,FP2) Sample(1,AirTemp_C,FP2) EndTable BeginProg Scan(1,Sec,1,0) 'Measure wiring panel temperature PanelTemp(PTemp_C,_60Hz) 'Measure type T thermocouple TCDiff(AirTemp_C,1,mV2_5C,1,TypeT,PTemp_C,True,0,_60Hz,1,0) 'Calculate the difference between air and panel temps DeltaT_C = AirTemp_C - PTemp_C 'Call data table(s) CallTable(DeltaT) NextScan EndProg 7.8.17.7 Capturing Events CRBasic example Capturing Events (p. 253) demonstrates programming to output data to a data table at the occurrence of an event. CRBasic Example 58. BeginProg / Scan / NextScan / EndProg Syntax 'Example programming to detect and record an event 'An event has a beginning and an end. This program records an event as occurring at 'the end of the event. The event recorded is the transition of a delta temperature 'above 3 degrees. The event is recorded when the delta temperature drops back below '3 degrees. 'The DataEvent instruction forces a record in data table Event each time an 'event ends. Number of events is written to the reserved variable 'EventCount(1,1). In this program, EventCount(1,1) is recorded in the 'OneMinute Table. 'Note : the DataEvent instruction must be used within a data table with a 'more frequent record interval than the expected frequency of the event. 'Declare Variables Public PTemp_C, AirTemp_C, DeltaT_C Public EventCounter 253