Campbell CR9000, Instruction Manual

Page: 190 / 218

Section 9. Program Control Instructions
9-4
Parameter
& Data Type Enter
Process
empty or 1
This is an optional parameter on the BeginBurstTrigger instruction. If set to 1 the measurements or
calculations within BeginBurstTrigger … EndBurst… will be available to output when the burst is
complete. If not present, the variables set by these measurements or calculations will retain the value(s)
from the last pass through the scan.
BurstTrigger
The variable or expression to test for the trigger. When the trigger condition is true, a
counter is started which increments with each following scan. When the counter equals
ScansAfterTrigger the program will exit the Scan(...) Next Scan loop and process the data in
the burst buffer.
Variable, or
Value Result
Expression 0 Do not trigger
≠
0
Trigger
ScansBefore
Constant The ScansBeforeStartTrigger parameter specifies the number of scans that occur prior to the
StartTrigger to include in the burst output. If the Start Trigger is detected before this number
of scans have been completed, there will be fewer values before the trigger.
StartTrigger
If the StartTrigger condition is true (nonzero), all measurements in the scan are executed until
the StopTrigger evaluates as true and the ScansAfterTrigger have been completed.
Constant Value Result
Variable or 0 Do not trigger
Expression
≠
0
Trigger
StopTrigger
The variable or expression to test for the trigger. Once the StopTrigger is true (nonzero)
measurements in the scan are executed until the ScansAfterStopTrigger have been completed
Constant Value Result
Variable or 0 Do not trigger
Expression
≠
0
Trigger
ScansAfter
Trigger
Constant
The number of scans to execute after the BurstTrigger or StopTrigger evaluates true. For the
EndBurstTrigger instruction, the number of pre-trigger scans is equal to the total scans in
the Scan(...) instruction minus the ScansAfterTrigger
FillandStop State of burst buffer, determines which data are saved if the triggered scans exceed the
Constant Value Result capacity of the burst buffer
0 Ring Memory: The last data are saved and processed
≠
0
Fill and Stop = true. The first data are saved and
processed
Burst Trigger Example
This example program monitors two accelerometers. When the first
accelerometer exceeds 5 G's there will be 2000 pre-trigger scans and 8000
post-trigger scans recorded.