Mitsubishi MELSEC-F FX3U Series User Manual

B-26
5 Buffer Memory (BFM)
5.4 Details of Buffer Memories
FX 3U /FX 3UC Series PLC User's Manual - Analog Control Edition
FX3UC-4AD (4-channel Analog Input)
5.4.2 BFM #2 to #5: Number of averaging time
Setting range: 1 to 4095
Initial value: K1
Numeric data type: Decimal (K)
To change the channel data type from the immediate data (channels 1 to 4: BFM #10 to #13) to the average
data, set the desired number of averaging time (channels 1 to 4 : BFM #2 to 5).
The relation between the set number of averaging time and the corresponding operation is shown in the
following table.
→ For a detailed description of channel data update timing, refer to Subsection 5.4.4.
1. Application
If the measurement signal contains comparatively reduced ripple noise, such as supply voltage frequency,
averaging will result in obtaining of stable data.
2. Cautions regarding number of averaging time setting
• To use the averaging function, be sure to set the digital filter of the corresponding channel to "0". (Digital
filter setting: BFM #6 to #9 for channels 1 to 4)
To use the digital filter function, be sure to set the number of averaging time of the corresponding channel
to "1". (Number of averaging time: BFM #2 to #5 for channels 1 to 4)
If the number of averaging time is set to a value other than "1" and the digital filter (BFM #6 to #9 for
channels 1 to 4) is set to a value other than "0", the digital filter setting error (b11 of BFM #29) will occur.
• If one of the channels uses the digital filter, the A/D conversion time will be set to 5 ms for all the channels.
• If the number of averaging time is out of the setting range, the number of averaging time setting error (b10
of BFM #29) will occur.
• If the number of averaging time is set, the data history function cannot be used.
Number of
averaging
time (BFM
#2 to #5)
Channel data (BFM #10 to #13) type Error descriptions
0 or less
Immediate data
(Each time the A/D conversion is performed, the channel
data will be updated.)
K0 will be set, and the number of
averaging time setting error (b10 of
BFM #29) will occur.
1 (initial
value)
Immediate data
(Each time the A/D conversion is performed, the channel
data will be updated.)
-
2 to 400
Average data
(Each time the A/D conversion is performed, the average
value will be calculated and the channel data will be
updated.)
-
401 to 4095
Average data
When the A/D conversion data reaches the number of
averaging time, the average data will be calculated and the
channel data will be updated.)
-
4096 or more
Average data
(Each time the A/D conversion is performed, the channel
data will be updated.)
4096 will be set, and the number of
averaging time setting error (b10 of
BFM #29) will occur.

Mitsubishi MELSEC-F FX3U Series Specifications

General

Brand	Mitsubishi
Model	MELSEC-F FX3U Series
Category	Controller
Language	English