User`s guide

158 53220A/53230A User’s Guide
5 Triggering and Gating
nal gate signals are applied to the counter’s rear panel ‘Gate In/Out’ BNC or to
the channel 1 or channel 2 input.
Frequency Measurements
For frequency and period measurements the command used to set/change the
gate source is:
[SENSe:]FREQuency:GATE:SOURce {TIME|EXTernal|INPut[1]|
INPut2|ADVanced}
[SENSe:]FREQuency:GATE:SOURce? (query form)
- gate source TIME is used to achieve a desired resolution in number of digits.
It uses an internal gate signal and is the default gate source. It enables the gate
to remain open for a specified period while the input signal is measured. The
longer the gate time, the greater the resolution.
Resolution and Gate Time
Reading resolution (in digits) is a function of the counter’s gate time, measure-
ment mode (AUTO, CONTinuous, RECiprocal - Chapter 3), and resolution
enhancement algorithm. Resolution enhancement (R
E
), which is defined in the