Mitsubishi Electric MELSEC FX Series - Page 391

7 Applied Instructions
7.8 External FX I/O Device
389
FXCPU Structured Programming Manual
(Basic & Applied Instruction)
1
Outline
2
Instruction List
3
Configuration of Instruction
4
How to Read Explanation of Instructions
5
Basic Instruction
6
Step Ladder Instructions
7
Applied Instructions
8
Interrupt Function and Pulse Catch Function
A
Relationships between devices and addresses
Extension function
When the extension function is validated by turning ON M8161, the 1-byte alphanumeric character string of
the device specified by is converted into ASCII code, and sequentially transferred into the device
specified by only in the lower 8 bits (1 byte).
The extension function is not available when FX
U PLC is V2.30 or earlier.
Higher 8 bits are H00.
Related devices
Cautions
1. Number of bits occupied in device
1) When extension function is OFF
- The device specified by occupies the value of number of characters ÷ 2 bits. (The remainder is
carried over.)
2) When extension function is ON
- The device specified by occupies the same number as the number of characters.
2. When using RS, ASCI, HEX, CCD
The extension function flag M8161 is a common flag used in other instructions.
When above instructions are used together with ASC instruction, you must execute the program of turning
ON or OFF the M8161 immediately before the ASC instruction so as to avoid its effect.
3. Object devices are limited.
S1: FX3U, FX3UC PLCs only are applicable.
Higher 8 bits Lower 8 bits Character string
00 41 A
+1
00 42 B
+2
00 43 C
+3
00 44 D
+4
00 45 E
+5
00 46 F
+6
00 47 G
+7
00 48 H
Device Name Content
M8161 Function extension flag
8-bit processing mode of ASC, RS, ASCI, HEX, CCD instruction
OFF : Every 2 characters are stored in the sequence of lower 8 bits, higher 8 bits (2 characters/
word).
ON : Characters are stored in lower 8 bits character by character (1 character/word).
Command input
M8161
M8000
M8161
Example:
ABCDEFGH
ASC
EN
s
ENO
d
1-byte alphanumerics of
8 characters entered from
personal computer
Head device for storing
ASCII code