API Command Reference Appendix A
A-28 NetScan User’s Manual
I - Set Scan Interval
TYPE
Acquisition
EXECUTION
Deferred
SYNTAX
Inorm,
acq
Set the two configurable scan intervals of the unit where norm and acq are
the normal and acquisition scan intervals which have the form:
hh:mm:ss.t where hh is hours, mm is minutes, ss is seconds, and t is
tenths of a second.
I?
Query scan interval selection.
DESCRIPTION
The Set Scan Interval (I) command is used to set one of the following two distinct scan intervals:
The first is the “normal” scan interval, used when the unit is collecting scans before the start trigger has occ urred
or after stop trigger has occurred. Scans in these two regions are called pre-trigger scans and pos t -s top scans,
respectively.
The second is the “acquisition” scan interval, used when the unit is acquiring scans aft er the start trigger has
occurred but before the stop event has occurred. Scans in this region are referred to as post -t ri gger s cans.
The norm and acq arguments represent the normal and acquisition scan intervals, respec t i vel y.
The scan interval can be set to run as fast as the current unit configuration will allow. This is referred to as “fast
mode”. Each of the two scan intervals can be configured as such by specifying 00:00:00.0 as t he argum ent
for the desired scan interval.
When the I command is interrogated by the unit, the unit will determine, by examining its current channel
configuration, if it is capable of running at the desired interval. If the unit det erm ines that it is not capable of
running at the desired interval, it will automatically enable fast mode for the interval(s) in question. It will also
issue a Conflict Error to inform you that it is not running at the user-spec i f ied interval.
The scan interval can be programmed from a 24-hour period to a 0.1-second period in increments of 0.1 second.
If a scan interval of zero is programmed, the interval will default to fast mode. Likewise, if a scan interval is
programmed less than the unit is capable of running at, the interval will default to fast mode.
EXAMPLE
PRINT#1, “I01:00:00.0, 00:00:00.0X
“
‘ Set normal scan interval to once every hour and
acquisition interval to fast mode
PRINT#1, “I?X”
‘ Query the current scan intervals
LINE INPUT #1, I$
PRINT I$
‘ Screen shows I01:00:00.0,00:00:00.0