Bfm#72][Bfm#112][Bfm#152][Bfm#192] Primary Delay Digital Filter Setting - Mitsubishi Electric MELSEC FX Series User Manual

FX -4LC User's Manual
3U

8.2.36 [BFM#72][BFM#112][BFM#152][BFM#192] Primary delay digital filter setting

To these buffer memories, enter the primary delay digital filter for reducing fluctuations caused by noise in the
measured value (MV).
The effect of noise is mitigated by setting the time constant of the digital filter here in accordance with the
control target characteristics and noise level.
Entering too small a value may not give the filter a beneficial effect. Entering too large a value deteriorates the
input response.
BFM No.
CH1 CH2 CH3 CH4
#72 #112 #152 #192 Setting range : 0 to 100 (sec.)
Example of operation
Input of actual measured value (PV)
Input of measured value (PV) processed
by the primary delay digital filter
Caution
• The primary delay digital filter is invalid when "0" is entered, and the measured value is acquired in the
sampling period (250ms).
• When the measured value (PV) before processing by the digital filter is outside the acquisition range (input
value error) continuously in 2 sampling periods, the digital filter is not applied.
Description
Pulse input caused by noise
Time
Input amplitude
Time
Initial
value
0
Time
Amplitude processed by the filter
Time
8 Buffer Memory
8.2 Buffer Memory Details
R/W Backup
R/W
99
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4
5
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9
10