Series 2280 Precision DC Power Supply Reference Manual
Section 4: Measurement optimization
077085503 / March 2019
4-7
Setting the displayed digits using SCPI commands
To set the number of displayed digits using SCPI commands:
SENSe:VOLTage:DIGits <n>
SENSe:CURRent:DIGits <n>
SENSe:CONCurrent:DIGits <n>
Where
<n>
is:
4
= 4.5 digit resolution
5
= 5.5 digit resolution
6
= 6.5 digit resolution
Filtering measurement data
Filters allow you to compute an average from a number of measurements. Averaging can reduce
measurement fluctuations due to noise levels. This can help you produce more accurate
measurements.
The Series 2280 provides a moving average filter function. Note that the greater the number of
measurements that are averaged, the slower the averaged sample rate, but the lower the noise error.
Trade-offs between speed and noise are normally required to tailor the instrument settings to your
measurement application.
If you create test algorithms and you are using the averaging filters, make sure the algorithms clear
the filter memory stacks at appropriate times to avoid averaging an inappropriate set of
measurements.
Moving average filter
When the moving average filter is selected, the measurements are added to the stack continuously
on a first-in, first-out basis. As each measurement is made, the oldest measurement is removed from
the stack. A new averaged sample is produced using the new measurement and the data that is now
in the stack.
Note that when the moving average filter is first selected, the stack is empty. When the first
measurement is made, it is copied into all the stack locations to fill the stack. A true average is not
produced until the stack is filled with new measurements.
