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FX3G/FX3U/FX3UC Series Programmable Controllers
Programming Manual - Basic & Applied Instruction Edition
4 Devices in Detail
4.12 Pointer [P and I]
4.12 Pointer [P and I]
4.12.1 Numbers of pointers
The table below shows numbers of pointers (P and I). (Numbers are assigned in decimal.)
When using a pointer for input interrupt, an input number assigned to it cannot be used together with a "high speed
counter" or "speed detection (FNC 56)" which uses the same input range.
1. FX3U/FX3UC PLC
2. FX
3G PLCs
4.12.2 Functions and operation examples of pointers for branch
The roles and operations of pointers for branch are as described below.
Because all of these pointers are combined with applied instructions, refer to the explanation of each instruction for the
detailed method.
→ For details on interrupt function, refer to Chapter 36.
1. Applied instructions using pointers for branch (P)
• CJ (FNC 00) (conditional jump)
• CALL (FNC 01) call subroutine
• Role of pointer P63 for jump to the END step
P63 is a special pointer for jumping to the END step
when the CJ (FNC 00) instruction is executed.
Note that a program error will occur when P63 is
programmed as a label.
→ Refer to "5. Label unnecessary for the
pointer P63" in Section 8.1.
For branch
For input interrupt/input delay
interrupt
For timer interrupt
For counter
interrupt
For jump to END step
P0 to P62
P64 to P4095
4095 points
P63
1 point
I00(X000) I30(X003)
I10(X001) I40(X004)
I20(X002) I50(X005)
6 points
I6
I7
I8
3 points
I010 I040
I020 I050
I030 I060
6 points
For branch For input interrupt For timer interrupt
For jump to END step
P0 to P62
P64 to P2047
2047 points
P63
1 point
I00(X000) I30(X003)
I10(X001) I40(X004)
I20(X002) I50(X005)
6 points
I6
I7
I8
3 points
FNC 00
CJ
P 0
Jump
X001
Label
P0
When X001 turns ON, the PLC jumps to a label
position specified by CJ (FNC 00) instruction,
and executes the subsequent program.
FNC 01
CALL
P 1
Jump
X001
Label
P1
FNC 06
FEND
FNC 02
SRET
Main program
Subroutine
program
Return
When X001 turns ON, the PLC executes a
subroutine in the label position specified by
CALL (FNC 01) instruction, and then returns to
the original position by SRET (FNC 02)
instruction.
Label
P63
FNC 00
CJ
P 63
END
Should not be programmed.