
72 53220A/53230A User’s Guide
3 53220A/53230A Measurements
CONTinuous - configures the counter for continuous, resolution-enhanced,
gap-free measurements. These measurements are used by the counter's Allan
Deviation feature when estimating stability.
In CONTinuous mode a trigger count of ‘1’ is the only value allowed, and all
samples (readings) per trigger are taken within a single (hardware) gate
open/gate close sequence and computed back-to-back. There is no lag (dead
time) between readings that otherwise occurs with the per-sample gate
open/gate close sequence of the AUTO and RECiprocal modes.
Figure 3-1 and the following paragraphs describe continuous, gap-free mea-
surements with an example one second gate time.
Figure 3-1. 53230A Continuous, Gap-Free Measurement Sequence.
gate open
Reading #1
Reading #2
Reading n
start
2341
stop
5
1
start
234
5
stop
start
1
234
5
stop
gate closed
gap-free
‘stop’ edge of previous reading
is ‘start’ edge of next reading
subsequent readings based on number
of edges for first reading
dges required for reading
etermined by gate time
gap-free
Gate In/Out BNC:
OUTput:STATe ON
OUTput:POLarity NORMal
CONFigure:FREQuency [<expected value>, <resolution>, <channel
TRIGger:COUNt 1
SAMPle:COUNt <count>
SENSe:FREQuency:MODE CONTinuous
SENSe:FREQuency:GATE:SOURce TIME
SENSe:FREQuency:GATE:TIME 1
...
...
gate time (1s) gate time (1s) gate time (1s)
firmware controlled – will see fluctuations
on the output BNC but readings are continuous (gap free)
Comentários a estes Manuais