User`s guide

Operating and Programming 3
L4400 User’s Guide 73
• Mx+B scaling and alarm limits (L4450A, L4452A) are applied to
measurements during a scan and all data is stored in volatile memory.
• The
CONFigure and MEASure? commands (L4450A, L4452A)
automatically set the scan interval to immediate (0 seconds) and the
scan count to 1 sweep.
• Th
e instrument sets the scan interval to immediate (0 seconds) after a
Factory Reset (
*RST command). An Instrument Preset (SYSTem:PRESet
command) or Card Reset (
SYSTem:CPON command) does not change 
the setting.
The following program segment configures
the instrument for an interval
scan.
TRIG:SOURCE TIMER
TRIG:TIMER 5
TRIG:COUNT 2
INIT
Select interval time mode 
Set the scan interval to 5 seconds 
Sweep the scan list 2 times 
Initiate the scan
Note: T
o stop a scan, send the ABORt command.
Manual Scanning
In this configuration, the instrument waits for a command before
sweeping through the scan list.
• All re
adings from the scan are stored in volatile memory. 
Readings accumulate in memory until the scan is terminated 
(until the trigger count is reached or until you abort the scan).
• Y
ou can specify a trigger count which sets the number of scan trigger
commands that will be accepted before terminating the scan. See
“Trigger Count" on page 75 for more information.
• Mx+B scaling and alar
m limits (L4450A, L4452A) are applied to
measurements during a manual scanning operation and all data is
stored in volatile memory.
The following program segment configures t
he instrument for a manual
scanning operation.
TRIG:SOURCE BUS
TRIG:COUNT 2
INIT
Select bus (manual) mode 
Sweep the scan list 2 times 
Initiate the scan
Then, send the
*TRG (trigger) command to begin each scan sweep. 
Note: T
o stop a scan, send the ABORt command.