Pointer [P And I]; Numbers Of Pointers; Functions And Operation Examples Of Pointers For Branch - Mitsubishi FX3U Series Programming Manual

FX /FX Series Programmable Controllers
3U 3UC
Programming Manual - Basic & Applied Instruction Edition
4.11

Pointer [P and I]

4.11.1 Numbers of pointers

The table below shows numbers of pointers (P)(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.
For branch
FX / P0 to P62
3U
P64 to P4095
FX
3UC
PLC 4095 points

4.11.2 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.
1. Applied instructions using pointers for branch (P)
• CJ (FNC 00) (conditional jump)
X001
Label
P0
• CALL (FNC 01) call subroutine
X001
Label
P1
• Role of pointer P63 for jump to the END step
Label
P63
Should not be programmed.
For input interrupt/input delay
For jump to
END step
I00 (X000) I30 (X003)
P63 I10 (X001) I40 (X004)
1 point I20 (X002) I50 (X005)
→ For the details of interrupt function, refer to Chapter 32.
FNC 00
P 0
CJ
Jump
FNC 01
P 1
CALL
Main program
Jump
FNC 06
FEND
Subroutine
program
FNC 02
Return
SRET
FNC 00
P 63
CJ
END
For timer interrupt
interrupt
I6
I7
I8
6 points 3 points
When X001 turns ON, the PLC jumps to a label
position specified by CJ (FNC 00) instruction,
and executes the subsequent program.
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.
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 accur when P63 is
programmed as a label.
→ Refer to "5. Label unnecessary for the
4 Devices in Detail
4.11 Pointer [P and I]
For counter
interrupt
I010 I040
I020 I050
I030 I060
6 points
pointer P63" in Section 8.1.
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