Reading/Writing Buffer Memory; Assigned Unit Number; 12.1.2 How To Read/Write From/To Buffer Memory - Mitsubishi FX3U-20SSC-H User Manual

FX -20SSC-H Positioning Block User's Manual
3U
12.1

Reading/Writing Buffer Memory

12.1.1 Assigned unit number

1. Assigned unit number
The unit number for the 20SSC-H is automatically assigned No.0 to No.7 starting from the special function
unit/block closest to the PLC main unit.
• In the FX series
3U
FX
3U
Main unit
• In the FX series
3UC
Unit No.0
(built-in CC-Link/LT)
FX -
3UC
32MT-LT
Main unit

12.1.2 How to read/write from/to buffer memory

To read/write from/to buffer memory in the 20SSC-H, use the FROM/TO instructions or applied instructions
that directly specify the buffer memory.
To directly specify the buffer memory, FX
Note
Buffer memory that is assigned in 32 bits must use 32-bit instructions to read/write.
Data cannot be correctly read/written from/to buffer memory assigned in 32 bits if 16-bit read/write
instructions are used.
1. Direct specification of buffer memory
The following setting device is specified for the source or destination of an applied instruction.
Unit No. (0 to 7)
1) Example 1
In the following program example, data is read from the buffer memory (BFM #1,#0) in unit No.1 to data
registers (D11, D10).
Read
command
Unit No.0
Input/output Special
extension block function block
Unit No.1
Input/output Special function
extension block block
/FX
3U
U \G
Buffer memory No. (0 to 15399)
FNC 12
DMOV
Unit No.
Buffer memory No.
Unit No.1
Special Input/output
function block extension block
Unit No.2
Special function Input/output
block extension block
PLC applicable software (GX Developer) is required.
3UC
is substituted with a
number
U1\G0 D10
12 Program Example
12.1 Reading/Writing Buffer Memory
Unit No.2
Special
function unit
Unit No.3
Special function
unit
Transfer
result
11
12
13
A
B
159