Chapter 5 299
Programming Fundamentals
Improving Measurement Speed
Programming Fundamentals
Put ADC Ranging in Bypass for FFT Measurements
Setting ADC ranging to the Bypass mode can speed FFT measurements
up by 10% to 50%. (Use ADC:RANG NONE) Bypass allows triggered
FFT measurements to occur at the trigger time instead of following an
autoranging time, so it can improve measurement speed. It does,
however, add additional noise degrading your signal to noise level, so it
should be used carefully.
Minimize DUT/instrument setup changes.
• Some instrument setup parameters are common to multiple
measurements. You should look at your measurement process with
an eye toward minimizing setup changes. If your test process
involves nested loops, make sure that the inner-most loop is the
fastest. Also, check if the loops could be nested in a different order to
reduce the number of parameter changes as you step through the
test.
• Are you are using the measurements under the
MEASURE key?
Remember that if you have already set your Meas Setup parameters
for a measurement, and you want to make another one of these
measurements later, use READ:<meas>?. The MEASure:<meas>?.
command resets all the settings to the defaults, while READ changes
back to that measurement without changing the setup parameters
from the previous use.
• Are you are using the Measurements under the
MEASURE key?
Remember that Mode Setup parameters remain constant across all
the measurements in that mode (e.g. center/channel frequency,
amplitude, radio standard, input selection, trigger setup). You don’t
have to re-initialize them each time you change to a different
measurement.
Consider using LAN instead of GPIB.
LAN allows faster I/O of data, especially if you are moving large blocks
of data. You will not get this improved throughput if there is excessive
LAN traffic (i.e. your test instrument is connected to enterprise LAN).
You may want to use a private LAN that is only for your test system.
Using an Option Mode: Minimize the number of GPIB
transactions.
When you are using the GPIB for control of your instrument, each
transaction requires driver overhead and bus handshaking, so
minimizing these transactions reduces the time used.
• You can reduce bus transactions by sending multiple commands per
transaction. See the information on “Putting Multiple Commands on
To Next Page
Loading...
Need help?
General
