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dL
PV input filter
The value of dL will determine the ability of filtering noise.
There is one intermediate-value filter system and one second order integral digital
filter system in AI series instrument. Intermediate value filter takes intermediate value
among three continuous values, while integral filter has the same effect as
resistance-capacity integral filter. If measurement input fluctuates due to noise, then
digital filter can be used to smooth the input. Parameter “dL” may be configured in the
range of 0 to 20, among which, 0 means no filter, 1 means intermediate-value filter
and 2
～
20 means that intermediate-value filter and integral filter can be selected
simultaneously.
When a large value is set, the measurement input is stabilized but the response
speed is slow. Generally, it can be set to 1 to 3.
If great interference exists, then you can increase parameter “dF” gradually to make
momentary fluctuation of measured value less than 2 to 5.
When the instrument is being metrological verified, “dF” s can be set to 0 or 1 to
shorten the response time.
dL