Campbell Scientific CR5000 Measurement and Control Module - Manual (Page 224)

Section 9. Program Control Instructions
9-18
the minimum time for the SlowSequence scan interval is the product of the
number of SlowSequence measurement segments and the primary scan
interval. One function of a SlowSequence is to update the calibration table.
The measurements in a single "scan" of the SlowSequence may be spread out
over a longer time period because the measurements can be parceled into
multiple primary scans.
When more than one SlowSequence is used in a program, certain combinations
of the main program scan rate and the SlowSequence scan rates may result in a
lower priority SlowSequence never being executed. If the interval for a higher
priority SlowSequence arrives before the lower priority SlowSequence can be
sliced in, the lower priority SlowSequence will never be performed. Each
combination of main program and SlowSequence program segments must be
evaluated to determine if there is sufficient time to allow lower priority scans
to be executed.
Low priority DataTables can be included in the SlowSequence scan by listing
them after the SlowSequence instruction. It should be noted that time stamped
data written to SlowSequence DataTables will be stamped with the start time of
the last SlowSequence scan.
SlowSequence Example
The example uses SlowSequence to calibrate the datalogger every sixty
seconds.
'Calibrate
Public Temp1
Public Calib1(60)
DataTable(Table1,1,600)
DataInterval(0,1,sec,1)
Sample(1,Temp1,FP2)
EndTable
BeginProg
Scan(20,mSec,0,0)
PanelTemp (Temp1,250)
CallTable Table1
Next scan
SlowSequence
Scan (60,Sec,0,0)
Calibrate(Calib1)
Next scan
EndProg