Mitsubishi Electric MELSEC-Q00U(J)CPU User Manual

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CHAPTER 4 DEVICES
4
4.10 Pointer (P) 4.10.2 Common pointer
4.10.2 Common pointer
The common pointer is used to call subroutine programs from all programs that are being executed.
(1) Common pointer range
In the PLC system tab of the PLC parameter dialog box, set the start number for the common pointer.
The common pointer range is from the specified pointer number to P4095.
However, the pointer number that can be entered here is a number higher than the total points used for the local
pointer.
Ex.
If a total of 400 points are used in three programs (100 points in each of Program A and Program B, and
200 points in Program C), for example, P400 and higher numbers can be set for the common pointer.
(2) Precautions
• The same pointer number cannot be used as a label. Doing so will result in a "Pointer configuration error"
(error code: 4021).
• If the total number of the local pointer points used in several programs exceeds the start number of the
common pointer, a "Pointer configuration error (error code: 4020) will occur.
The jump instructions are not capable of executing a jump to the common pointer in other programs.
Use the common pointer with subroutine call instructions only.
Program A
FEND
CALL P204
Program C
P204
P205
CALL P0
RET
RET
END
Program B
FEND
CALL P205
Label
Set the start number for
the common pointer.
Program A Program B Program C
Using P0 to P99
Using P0 to P99
Using
P0 to P199
100 points of
P0 to P99 occupied
100 points of
P0 to P99 occupied
Total of 400 points
are used.
200 points of
P0 to P199 occupied
P400 and higher numbers
can be used for the common pointer.

Mitsubishi Electric MELSEC-Q00U(J)CPU Specifications

General

Series	MELSEC-Q
Model	Q00U(J)CPU
Power supply voltage	24 VDC
Operating temperature	0 to 55 °C
Number of I/O Points	4096 points
Programming Language	Ladder, Instruction list, SFC, Function block, Structured text
Execution Speed (LD instruction)	0.08 µs
Dimensions	90 x 90 x 90 mm
Weight	0.5 kg
Processing speed	0.08 µs
Built-in ports	RS-232
Communication	Ethernet, Serial
Type	Programmable Logic Controller (PLC)

Summary

SAFETY PRECAUTIONS

Design Precautions

Configure external safety circuits and understand output status upon fault detection for system safety and reliability.

CONDITIONS OF USE FOR THE PRODUCT

INTRODUCTION

MANUALS

CPU module user's manual

Details specifications, functions, maintenance, troubleshooting, and error codes of CPU modules.

Programming manual

Describes instructions, programming, and error codes for various programming languages like SFC.

MANUAL PAGE ORGANIZATION

TERMS

PART 1 PROGRAMMING

CHAPTER 1 BASIC PROCEDURE FOR PROGRAMMING

Covers fundamental programming steps: project creation, program creation, conversion, writing, checking, and saving.

CHAPTER 2 APPLICATION OF PROGRAMMING

Details programming concepts like memory, files, base units, I/O assignment, and scan time structure.

PART 2 FUNCTIONS

CHAPTER 3 FUNCTIONS

Describes various functions of the Universal model QCPU, including lists, operations, and settings.

CHAPTER 4 DEVICES

4.1 Device List

Lists all internal user devices, internal system devices, link direct devices, and other devices with their points and ranges.

4.2 Internal User Devices

Details internal user devices like input (X), output (Y), internal relay (M), latch relay (L), annunciator (F), edge relay (V), timers, counters, registers.

4.3 Internal System Devices

Describes fixed internal system devices like function devices (FX, FY, FD), special relays (SM), and special registers (SD).

4.4 Link Direct Device

Explains direct access to link devices in CC-Link IE, MELSECNET/H modules, and their specification methods.

4.5 Module Access Devices

Details intelligent function module device and cyclic transmission area device for accessing buffer memory and shared memory.

4.6 Index Register (Z)/Standard Device Resister (Z)

Explains index registers for indirect specification and standard device registers for higher speed operations.

4.7 File Register (R)

Describes file register usage, storage location, size, differences from link refresh, and registration procedures.

4.8 Extended Data Register (D) and Extended Link Register (W)

Explains extended data and link registers as extensions to data and link registers, using file register area.

4.9 Nesting (N)

Details nesting (N) device used with master control instructions for programming operation conditions.

4.10 Pointer (P)

Explains pointers used for jump and subroutine call instructions, including local and common pointer types.

4.11 Interrupt Pointer(I)

Describes interrupt pointers for starting interrupt programs and lists available interrupt factors and their priorities.

4.12 Other Devices

Covers SFC block devices (BL), Network No. specification devices (J), I/O No. specification devices (U), and Macro instruction argument devices (VD).

CHAPTER 5 CONSTANTS

5.1 Decimal Constant (K)

Specifies decimal data in sequence programs using the 'K' notation.

5.2 Hexadecimal Constant (H)

Specifies hexadecimal or BCD data in sequence programs using the 'H' notation.

5.3 Real Number (E)

Specifies real numbers in sequence programs using the 'E' notation for floating-point data.

5.4 Character String (" ")

Specifies character strings in sequence programs using characters enclosed in quotation marks.

CHAPTER 6 CONVENIENT USAGE OF DEVICES

6.1 Global Device

Describes global devices that can be shared by multiple programs, stored in CPU module device memory.

6.2 Local Device

Explains local devices used independently for each program, allowing multiple programs without conflicts.

APPENDICES

Appendix 1 Parameters

Details parameters for programmable controller systems, including PLC, Network, and Remote Password settings.

Appendix 2 Functions Added or Changed by Version Upgrade

Lists functions added or changed based on CPU module and programming tool versions.

Appendix 3 CPU Module Processing Time

Describes scan time structures and CPU module processing times for various operations.

Appendix 4 Data Used in Sequence Programs

Explains numeric representations like BIN, HEX, BCD, and real numbers used in sequence programs.

Appendix 5 Replacing Basic Model QCPU or Qn(H)CPU with QnUCPU

Provides precautions and methods for replacing basic or high performance QCPU with Universal model QCPU.

Appendix 6 Precautions for Replacing QnUD(E)(H)CPU with QnUDVCPU/QnUDPVCPU

Details precautions and replacement methods when migrating from QnUD(E)(H)CPU to QnUDVCPU/QnUDPVCPU.

Appendix 7 Precautions for Replacing QnPHCPU with QnUDPVCPU

Provides precautions for replacing QnPHCPU with QnUDPVCPU.

Appendix 8 Precautions for Using GX Works2 and Differences with GX Developer

Covers precautions and differences when using GX Works2 versus GX Developer.

Appendix 9 Ways to Use Different Types of the Backup/restoration Function

Explains how to use various types of backup/restoration functions for GOT and CPU modules.

REVISIONS

WARRANTY