Section 11: TSP command reference
Series 3700A System Switch/Multimeter Reference Manual
11-176
3700AS-901-01 Rev. D/June 2018
dmm.filter.type
This attribute defines the type of averaging filter that is used for the selected measure function when the
measurement filter is enabled.
Type
TSP-Link accessible
Affected by
Where saved
Default value
Attribute (RW)
Yes
Reset
DMM reset
Recall setup
Create configuration script
Save setup
1
(dmm.FILTER_REPEAT_AVG)
Usage
value
= dmm.filter.type
dmm.filter.type =
value
value
The filter type setting:
▪
Moving filter:
dmm.FILTER_MOVING_AVG
or
0
▪
Repeating filter:
dmm.FILTER_REPEAT_AVG
or
1
Details
The filter type setting only applies when
dmm.func
is set to one of the following:
•
"accurrent"
•
"acvolts"
•
"commonsideohms"
•
"dccurrent"
•
"dcvolts"
•
"fourwireohms"
•
"temperature"
•
"twowireohms"
Querying the setting for any other function returns
nil
. An error is generated if this setting is written
or read for any other function.
You can choose from two averaging filter types: Repeating and moving.
When the repeating average filter is selected, a set of measurements are made. These
measurements are stored in a measurement stack and averaged together to produce the averaged
sample. Once the averaged sample is produced, the stack is flushed and the next set of data is used
to produce the next averaged sample. This type of filter is the slowest, since the stack must be
completely filled before an averaged sample can be produced.
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.
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. The size of the stack is determined by the filter count setting.
