B-39
5 Buffer Memory (BFM)
5.4 Details of Buffer Memories
A
Common Items
B
FX
3UC
-4AD
C
FX
3U
-4AD-ADP
D
FX
3U
-4DA-ADP
E
FX
3U
-4AD-PT
-ADP
F
FX
3U
-4AD-TC
-ADP
G
PID Instruction
(FNC 88)
FX
3U
/FX
3UC
Series PLC User's Manual - Analog Control Edition
FX3UC-4AD (4-channel Analog Input)
5.4.17 BFM #91 to #94: Abrupt change detection value setting
Setting range: See below.
Initial value: See below.
Numeric data type: Decimal (K)
When channel data (BFM #10 to #13) is updated, if the difference between the previous value and the new
value is larger than the set abrupt change detection value (value set in BFM #91 to #94), the system will judge
that the channel data is changed abruptly.
The result of abrupt change detection will be written in BFM #27 as the abrupt change detection status data.
The abrupt change detection value setting range depends on the set input mode (BFM #0) as shown in the
following table:
1. Cautions regarding abrupt change detection value setting
To use the abrupt change detection value, be sure to turn on the abrupt change detection function (b2 of BFM
#22).
Input mode (BFM #0)
Setting range Initial value
Set
value
Description
0
Voltage input
(-10V
to +10V:-32000 to +32000)
1
to 32767
3200
1
Voltage input
(-10V
to +10V:-4000 to +4000)
1
to 4095
400
2
Voltage input
Analog value direct indication mode
(-10V
to +10V:-10000 to +10000)
1
to 10000
1000
3
Current input (4mA
to 20mA:0 to 16000) 1 to 8191
800
4
Current input (4mA
to 20mA:0 to 4000) 1 to 2047
200
5
Current input
Analog value direct indication mode
(4mA
to 20mA:4000 to 20000)
1
to 8191
800
6
Current input
(-20mA
to +20mA:-16000 to +16000)
1
to 16383
1600
7
Current input
(-20mA
to +20mA:-4000 to +4000)
1
to 4095
400
8
Current input
Analog value direct indication mode
(-20mA
to +20mA:-20000 to +20000)
1
to 20000
2000