Keithley 6220 DC, Руководство пользователя

Страница: 125 / 171

6-4 Averaging Filter, Math, and Buffer Model 6220/6221 User’s Manual
Return to Section 6 topics
Filter window
The averaging filter uses a “noise” window to control filter threshold. As long as
the signal remains within the selected window, A/D conversions continue to be
placed in the stack. If the signal changes to a value outside the window, the filter
resets, and the filtering process starts over.
The noise window, which is expressed as a percentage of measurement range,
allows a faster response time to large signal step changes (e.g., sweep step). A
reading conversion outside the plus or minus noise window fills the filter stack
immediately.
If the noise does not exceed the selected window, the reading is based on the
average of the reading conversions. If the noise does exceed the selected win-
dow, the reading is a single reading conversion, and new averaging starts from
this point.
The window can only be set remotely and can be assigned any value from 0.00%
to 10%. The filter window is expressed as a percent of range. For example, with
the Model 2182/2182A on the 10V range, a 10% window means that the filter win-
dow is ±1V.
Filter setup and control
When the averaging filter is enabled, the FILT annunciator turns on. For front
panel operation , the AVG key toggles the state of the averaging filter. The filter
can be configured while it is enabled or disabled.
To configure the filter, press CONFIG then AVG. From the TYPE menu item,
select the MOVING or REPEAT filter and press ENTER . From the COUNT menu
item, set the filter count (2 to 300) and press ENTER . Use the EXIT key to return
to the normal display state.
Remote programming – Averaging filter
The commands for averaging filter setup and control are listed in Table 6-2 . A pro-
gramming example follows the table.