Pointer [P And I]; Numbers Of Pointers; Functions And Operation Examples Of Pointers For Branch - Mitsubishi Electric FX3G SERIES Programming Manual

FX /FX /FX Series Programmable Controllers
3G 3U 3UC
Programming Manual - Basic & Applied Instruction Edition
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. FX /FX PLC
3U 3UC
For branch
P0 to P62
P64 to P4095
4095 points
2. FX PLCs
3G
For branch
P0 to P62
P64 to P2047
2047 points
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.
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.
146
For input interrupt/input delay
For jump to END step
P63
1 point
For jump to END step
P63
1 point
FNC 00
P 0
CJ
FNC 01
P 1
CALL
Jump
FNC 06
FEND
FNC 02
Return
SRET
FNC 00
P 63
CJ
END
interrupt
I00 (X000) I30 (X003)
I10 (X001) I40 (X004)
I20 (X002) I50 (X005)
6 points
For input interrupt
I00 (X000) I30 (X003)
I10 (X001) I40 (X004)
I20 (X002) I50 (X005)
6 points
→ For details on interrupt function, refer to Chapter 36.
When X001 turns ON, the PLC jumps to a label
position specified by CJ (FNC 00) instruction,
and executes the subsequent program.
Jump
When X001 turns ON, the PLC executes a
subroutine in the label position specified by
CALL (FNC 01) instruction, and then returns to
Main program
the original position by SRET (FNC 02)
instruction.
Subroutine
program
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.
4.12 Pointer [P and I]
For counter
For timer interrupt
interrupt
I6 I010 I040
I7 I020 I050
I8 I030 I060
3 points 6 points
For timer interrupt
I6
I7
I8
3 points
→ Refer to "5. Label unnecessary for the
pointer P63" in Section 8.1.
4 Devices in Detail