Mitsubishi Electronics FX3G ユーザーズマニュアル

243

/FX

3GC

/FX

3UC

Series

Programming Manual - Basic & Applied Instruction Edition

8 Program Flow – FNC 00 to FNC 09

8.10 FNC 09 – NEXT / End a FOR/NEXT Loop

Introdu

ction

ervi
ew

Instruction

evices

in Det

Specifi

ed the

vice

onst
ant

Bef
ore

mmi
ng

Bas
ic

Instruction

FN
C00-FN

Program Fl

FNC

10-FN

C19

Mov
e & Com

pare

FNC

20-FNC

Arith. & Lo

Operati

Errors

1. Watchdog timer error

When FOR-NEXT loop is repeated many times, the operation cycle (D8010) is too long, and a watchdog timer error
may occur. In such a case, change the watchdog timer time or reset the watchdog timer.

→ For details on changing the watchdog timer time, refer to Subsection 37.2.2.

→ For resetting the watchdog timer, refer to WDT (FNC 07) instruction.

2. Examples of wrong programs

The following programs are regarded as errors.

Program example

1. Program with three FOR-NEXT loops

When NEXT instruction does not exist

When NEXT instruction is located before FOR
instruction

When number of FOR instructions is not
equivalent to the number of NEXT instructions

← Not programmed

When NEXT instruction is located after FEND or
END instruction

END

← Not programmed

FNC 09

FNC 08

FOR

FNC 08

FOR

FNC 08

FOR

FNC 06

FEND

FNC 08

FOR

FNC 08

FOR

The loop [3] is repeated 4 times.

When the data value (current value) of D0Z
(D4 when Z is "4") is "6", the loop [2] is
repeated 6 times.

When X010 is OFF

When K1X000 is "7", the loop [1] is repeated
7 times.

When X010 is ON

The program execution jumps to the pointer P22,
and the loop [1] is skipped.

Number of times of repeating the loops [1],
[2] and [3]

X010 = ON

X010 = OFF

× 6 × 4 =168 times

× 4 = 24 times

4 times

[1]
[2]
[3]

0 time

24 times

4 times

X010

P 22

[1]

[2]

[3]

FNC 09

FNC 08

FOR

K 4

FNC 08

FOR

D 0Z

FNC 00

P 22

FNC 08

FOR

K1X000

FNC 09

7
times

6
times

4
times