User`s guide

53220A/53230A User’s Guide 207
53220A/53230A Math, Graphing, and Data Logging 6
not support continuous (gap free) measurements.
Example: Setting up an Allan Deviation Measurement (53230A)
CONF:FREQ (@1) // frequency measurement on ch 1
TRIG:COUN 1 // set trigger count
SAMP:COUN 300 // take 300 readings
SENS:FREQ:MODE CONT // set continuous gap-free mode
SENS:FREQ:GATE:TIME 1e3 // 1 ms gate time
CALC:STAT ON // enable CALCulate1 subsystem
CALC:AVER:STAT ON // enable statistics
INIT // initiated the measurements
*WAI // wait for all rdgs to complete
CALC:AVER:ADEV? // compute Allan deviation
Standard Deviation
Standard deviation is available with both counters using the command:
CALCulate[1]:AVERage:SDEViation?
The CALCulate1 subsystem and statistics must also be enabled before the
standard deviation can be determined.
Clearing/Resetting Statistics
The current set of reading statistics is clear by any of the following:
• enabling statistical functions - CALCulate[1]:AVERage[:STATe] ON
• a new measurement cycle - INITiate:IMMediate, READ?, MEASure?
• sending a new SCPI command or changing a current SCPI parameter
• a reset or instrument preset - *RST, SYSTem:PRESet
These steps also clear all readings in reading memory. To clear statistics with-
out clearing reading memory, the following command is used:
CALCulate[1]:AVERage:CLEar[:IMMediate]