Mitsubishi Electronics FX3G User Manual

FX

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3G

/FX

3GC

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3U

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3UC

 Series

Programming Manual - Basic & Applied Instruction Edition

2 Overview (Sequence Program)

Introdu

ction

Ov

ervi
ew

Instruction 

Li

st

D

evices 

in Det

ai

l

Specifi

ed the

De

vice

 &

 

C

onst
ant

Bef
ore

 

Pr

og

ra

mmi
ng

Bas
ic 

Instruction

FN
C00-FN

C0

9

Program Fl

ow

FNC

10-FN

C19

Mov
e & Com

pare

FNC

20-FNC

29

Arith. & Lo

gi

c 

Operati

on

The entry code can be registered to prevent erroneous read/incorrect write protection of created sequence programs.
With regard to online operations from GX Works2, GX Developer (Ver. 8.24A or later) and handy programming panels,
the program protection level can be set by the entry code specification method. In this case, such specification that
"changes of a program are disabled, but monitoring and changes of present values are enabled" is available.

→ Refer to the manual of the used programming tool.

By setting parameters, the device comment area (where Katakana, Kanji and alphanumeric characters are available)
can be secured in the program memory.

→ Refer to the manual of the used programming tool.

Programs can be changed while the PLC is operating (RUN mode).
By this function, programs can be adjusted and changed efficiently without stopping the machine.

→ Refer to the manual of the used programming tool.

The FX

3U

/FX

3UC

 PLCs Ver. 3.00 or later can store symbolic information (data indicating the program configuration

such as structure and labels).
By using this function, you can read the symbolic information from the PLC, and edit labels, function blocks, etc.
GX Works2 Ver. 1.62Q or later is required to store symbolic information.

→ Refer to the GX Works2 Version 1 Operating Manual (Common) for the details on symbolic information.

FX

3S

/FX

3G

/FX

3GC

/FX

3U

/FX

3UC

 PLCs are equipped with not only fundamental applied functions for data transfer, data

comparison, arithmetic operations, logical operations, data rotation, and data shift but also high-speed processing
instructions for I/O refresh, interrupt, comparison dedicated to high-speed counters, and high-speed pulse output as
well as initial state instructions by which standard operations for machine control are made into packages in the SFC
control. In this way, FX

3S

/FX

3G

/FX

3GC

/FX

3U

/FX

3UC

 PLCs have the specifications offering fundamental functions, high-

speed processing, and good operability. 

In addition, FX PLCs offer many handy instructions by which complicated sequence control is made into packages to
mitigate the load for creating sequence programs and save the number of I/O points.
FX PLCs also offer floating point arithmetic operations and PID operations to cope with more advanced control.

This subsection introduces representative ones among many applied instructions.

• Conditional jump (CJ/FNC 00)
• Call subroutine (CALL/FNC 01)
• Enable interrupt (EI/FNC 04)
• Disable interrupt (DI/FNC 05)
• Start a FOR/NEXT loop (FOR/FNC 08)

→ Refer to Chapter 8.

• Compare (CMP/FNC 10)
• Data comparison (FNC224 to FNC246)
• Floating point compare 

(ECMP/FNC110 and EZCP/FNC111)

• Zone compare (ZCP/FNC 11)
• High-speed counter compare (FNC 53 to FNC 55)
• High-speed counter compare with data table 

(HSCT/FNC280)

• Move (MOV/FNC 12)
• Floating point move (EMOV/FNC112)
• High-speed counter move (HCMOV/FNC189)
• Conversion to binary-coded decimal 

(BCD/FNC 18)

• Conversion to binary (BIN/FNC 19)
• Decimal to gray code conversion (FNC170) and 

gray code to decimal conversion (FNC171)

→ Refer to Chapter 9, Chapter 13, Chapter 18,