Plc; Buffer Memory Reading/Writing Method - Mitsubishi Electric FX3G User Manual

FX /FX /FX /FX /FX
3S 3G 3GC 3U 3UC
FX -4DA (4-channel Analog Output)
3U
5.2

Buffer Memory Reading/Writing Method

To read or write the buffer memory of FX
specification function
To use the buffer memory direct specification function
compatible with the PLC.
*1. This function is supported only in FX
5.2.1 Buffer memory direct specification (FX
When directly specifying the buffer memory, specify the following device in the source or destination area of
the applied instruction as follows:
Unit number (0 to 7)
1. Example 1
If the following program is created, data in buffer memory (BFM#10) of unit 1 will be multiplied by the data
(K10), and then the multiplication result will be output to the data registers (D10, D11).
READ command
Unit number
Buffer memory number
2. Example 2
If the following program is created, the value in the data register (D20) is added to K10 and written to buffer
memory (BFM#6) of unit 1.
WRITE command
Augend
5.2.2 FROM/TO instruction (FX
1. FROM instruction (Reading out BFM data to PLC)
Use FROM instruction to read out the data from the buffer memory.
In a sequence program, use this instruction as follows:
READ command
Unit number
Buffer memory number
If the above program is created, 1 point of data will be read out from the buffer memory BFM#10 of unit No.1
to the data register (D10).
2. TO instruction (Writing PLC data into BFM)
Use the TO instruction to write data to a buffer memory.
In a sequence program, use this instruction as follows:
WRITE command
Unit number
Buffer memory number
If the above program is created, 1 point of data (H3300) will be written to buffer memory (BFM#0) of unit No.1.
PLC User's Manual - Analog Control Edition
-4DA, use FROM/TO instructions or the buffer memory direct
3U
*1
.
/FX
3U
→ For a detailed description of the software compatible with the PLC,
U\G
FNC 22
U1\G10
MUL
FNC 20
D20
ADD
/FX /FX
3G 3GC
FNC 78
K1 K10
FROM
FNC 79
K1 K0
TO
*1
, however, it is necessary to adopt the software
PLCs.
3UC
/FX PLC only)
3U 3UC
Enter a numeric value in 
Buffer memory number (0 to 32766)
K10 D10
Multiplication result
Multiplier
K10 U1\G6
Addition
result
Addend
/FX

PLC)

3U 3UC
D10 K1
Number of transfer
data points
Transfer-to register
H3300 K1
Number of transfer
data points
Transfer source
5 Buffer Memory (BFM)
5.2 Buffer Memory Reading/Writing Method
refer to Section 1.4.
Unit number
Buffer memory number
E-17
A
B
C
D
E
F
G
H
I
J