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CHAPTER9 DEVICES
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9.9 Pointer (P)
9.9 Pointer (P)
(1) Definition
The pointer (P) is a device used in jump instructions (CJ, SCJ, or JMP) or subroutine call instructions (such as
CALL).
(2) Applications
Pointers can be used in the following applications.
• Specification of the jump destination in a jump instruction (CJ, SCJ, or JMP) and a label (start address of the
jump destination)
• Specification of the call destination of a subroutine call instruction (CALL or CALLP) and a label (start
address of the subroutine program)
(3) Pointer types
(a) Basic model QCPU
Since the Basic model QCPU cannot execute multiple programs, it has no distinction between the local and
common pointers.
(b) High Performance model QCPU, Process CPU, and Redundant CPU
There are the following two different pointer types.
• Local pointer ( Section 9.9.1) :
The pointer used independently in each program
• Common pointer ( Section 9.9.2) :
The pointer that can be called in all running programs by the subroutine call instruction.
(4) Number of available pointer points
• Basic model QCPU: 300 points
• High Performance model QCPU, Process CPU, and Redundant CPU: 4096 points
For the jump instructions and subroutine call instructions, refer to the following.
MELSEC-Q/L Programming Manual (Common Instruction)
Figure 9.84 Program using a pointer
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