Mitsubishi Electronics MELSEC-F Manuel D’Utilisation
B-27
5 Buffer Memory (BFM)
5.4 Buffer Memory Details
A
Comm
on I
te
te
ms
B
FX
3U
-4AD
FX
3UC
-4
A
D
C
FX
3U
-4A
D
D
-A
D
P
D
FX
3G
-2A
D
D
-BD
E
FX
3U
-4DA
F
FX
3U
-4D
A
A
-AD
P
P
G
FX
3G
-1D
A
A
-BD
H
FX
3U
-3
A-
ADP
I
FX
3U
-4
A
D
-P
T
-
A
D
P
J
FX
3U
-4A
D
D
-P
TW
-
A
A
D
P
FX
3G
/FX
3U
/FX
3UC
PLC User's Manual - Analog Control Edition
FX
3U
-4AD/FX
3UC
-4AD (4-channel Analog Input)
5.4
Buffer Memory Details
5.4.1
BFM #0: Input mode specification
Initial value (at delivery): H0000
Numeric data type: Hexadecimal (H)
Specify the input modes of channel 1 to 4.
4 hexadecimal digits are assigned to specify the input modes of the 4 channels.
Change the value of each digit to change the input mode of each channel. 0 to 8 or F can be set for each digit.
4 hexadecimal digits are assigned to specify the input modes of the 4 channels.
Change the value of each digit to change the input mode of each channel. 0 to 8 or F can be set for each digit.
The different types of input modes are shown in the following table:
→ For a detailed description of input characteristics, refer to Section 2.4.
*1.
The offset/gain values cannot be changed.
1. Cautions regarding input mode setting
• If the input mode is set (changed), the analog input characteristics will be changed automatically.
Furthermore, when the offset/gain value is changed, the characteristics can be set to the desired values.
(The resolution cannot be changed.)
(The resolution cannot be changed.)
• If the analog value direct indication (*1) is specified, the offset/gain value cannot be changed.
• It takes approximately 5 seconds to determine the input mode. For this reason, after changing the input
• It takes approximately 5 seconds to determine the input mode. For this reason, after changing the input
mode, be sure to wait for 5 seconds or more before writing other data.
• HFFFF (no channels used) cannot be set.
2. Caution regarding EEPROM writing
If data is written to BFM #0, #19, #21, #22, #125 to #129, or #198, the data will also be written to the 4AD
EEPROM.
The maximum number of EEPROM rewrites is 10,000 times. Therefore, when creating a program, do not
frequently write data to the above buffer memories (BFM).
EEPROM.
The maximum number of EEPROM rewrites is 10,000 times. Therefore, when creating a program, do not
frequently write data to the above buffer memories (BFM).
Set value
[HEX]
Input mode
Analog input
range
Digital output
range
0
Voltage input mode
-10V to +10V
-32000 to +32000
1
Voltage input mode
-10V to +10V
-4000 to +4000
2
*1
Voltage input
Analog value direct indication mode
Analog value direct indication mode
-10V to +10V
-10000 to +10000
3
Current input mode
4mA to 20mA
0 to 16000
4
Current input mode
4mA to 20mA
0 to 4000
5
*1
Current input
Analog value direct indication mode
Analog value direct indication mode
4mA to 20mA
4000 to 20000
6
Current input mode
-20mA to +20mA
-16000 to +16000
7
Current input mode
-20mA to +20mA
-4000 to +4000
8
*1
Current input
Analog value direct indication mode
Analog value direct indication mode
-20mA to +20mA
-20000 to +20000
9 to E
Setting not possible
-
-
F
Channel not used
-
-
H
ch4
ch3
ch2
ch1