Model 2281S-20-6 DC Power Supply and Battery Simulator Reference Manual
Section 4: Measurement optimization
077114601 / March 2019
4-5
Setting speed using SCPI commands
To set the NPLCs for current measurements, send the command:
:SENSe:CURRent:NPLCycles <n>
To set the NPLCs for concurrent measurements, send the command:
:SENSe:CONCurrent:NPLCycles <n>
To set the NPLCs for voltage measurements, send the command:
:SENSe:VOLTage:NPLCycles <n>
Where
<n>
is a value from 0.002 to 15 for 60 Hz and from 0.002 to 12 for 50 Hz. A value of 0.002
results in the fastest reading rates, and a value of 12 or 15 results in the lowest reading noise.
For example, to set the NPLCs for voltage measurements to 0.5, send the command:
SENSe:VOLTage:NPLCycles 0.5
Autozero measurements
When using the power supply function, the instrument must measure internal references
corresponding to the zero low and gain high references to ensure reading accuracy. The time interval
between reference updates is determined by the integration aperture that is used for each
customer-specified measurement and the internal reference analog-to-digital converter (ADC)
measurement.
The autozero measurement function is disabled when using the battery test and battery simulation
functions.
By default, the instrument automatically checks the references for each triggered reading. This can
result in a longer than expected time interval. This additional time can cause problems in the test
sequences in which measurement timing is critical.
To eliminate the extra time, the automatic internal reference ADC measurements can be disabled,
allowing the instrument to measure only the customer-specified portion of the reading.
When automatic reference measurements are disabled, the instrument speed per reading increases.
However, the instrument may gradually drift out of specification.
Measurement function
With autozero enabled, the number
of customer and internal reference
ADC measurements per reading
With autozero disabled, the number
of customer and internal reference
ADC measurements per reading
Concurrent (V + I)
5
2
Current (I)
4
1
Voltage (V)
3
1
