Agilent Technologies Agilent 34980A, User Manual

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64-Bit Digital I/O Module with Memory and Counter
10
34980A User’s Guide 285
Counter
The 34950A has two 10 MHz frequency counter/totalizer measurement
input channels. The counters can operate in two general modes:
Totalizer
mode, and Initiated Measurement mode. In the totalizer mode, the counter
acts as a basic totalizer. In the initiated measurement mode, the counter
can make frequency, period, duty cycle, and pulse width measurements.
Totalizer Mode
Totalizer mode is the default operating mode for the counters. When the
counter is configured for
TOTalizer
mode, it automatically starts running.
The totalized count can be read, reset, scanned, and monitored.
The simplest way to take a totalizer measurement is to use the
MEASure
form of the command. For example, the following command configures the
totalizer on the first bank, initiates the measurement, and returns the
result. The data is returned in a floating point format.
MEAS:COUN:TOT? READ, (@1301)
You can also reset the totalizer count by setting the parameter to
RRESet
.
For example, the following command configures the totalizer on the first
bank, initiates the measurement, and returns the result. The totalize count
is reset when the data is read.
MEAS:COUN:TOT? RRES, (@1301)
Totalizer counts begin as soon as the channel is configured for the totalize
measurement. You can stop a count by sending
SENSe:COUNter:ABORt
command and restart the count using the
SENSe:COUNter:INITiate
command.
The slope of the edges being counted can be configured using the
SENSe:COUNter:SLOPe
command. By default, when started, the totalizer
counts rising edges.
Additionally, you can control when the edges are counted by setting the
gate source to external and providing a gate signal on the gate input.
In external gate mode the counter totalizes when the gate is asserted.
The gate time setting controls how long the counter totalizes. Once the
external gate has been de- asserted a new measurement must be armed
via the
SENSe:COUNter:INITiate
command. The figure below shows an
externally gated totalizer measurement. The number of totalized counts is
‘5’ in this particular example.
Init
Ext Gate
Input