Mitsubishi MELSEC QCPU User Manual

6 - 116 6 - 116
MELSEC-Q/QnA
6 BASIC INSTRUCTIONS
The count processing performed on the present value is as shown below:
-32768 -32767 -2 -1 0 1 2 3276732766
When counting up
When countin
g
down
(4) Count processing conducted according to the UDCNT2 instruction begins when the count
command goes from OFF to ON, and is suspended when it goes from ON to OFF.
When the count command goes from OFF to ON once again, the count is restarted from the
value in effect when it was suspended.
(5) The RST instruction clears the present value of the counter designated at
D
and turns the
contact OFF.
POINTS
(1) The UDCNT2 instruction registers the argument device data to the work area of the CPU
module and the actual counting operation is processed as a system interrupt.
(The device data registered to the work area of the CPU module are cleared when the
command input is turned OFF or when the CPU module is STOPped and then RUN.)
Therefore, to count pulses, it is necessary to provide their ON and OFF time as long as the
interrupt time of the CPU module or longer.
The interrupt time of individual CPU module is shown below:
CPU module T
yp
e Name Interru
p
t Time
Hi
g
h Performance model QCPU, Process CPU 1ms
QnACPU 5ms
(2) The set value cannot be changed while a count operation performed according to the
UDCNT2 instruction is being executed (while the command input is ON).To change the set
value, first turn the command input off.
(3) Counters designated by the UDCNT2 instruction cannot be used by any other instruction.
If they are used by other instructions, they will not be capable of returning an accurate
count.
(4) The UDCNT2 instruction can be used as many as 5 times within all the programs being
executed.
The sixth and the subsequent UDCNT2 instructions are not processed.
[Operation Errors]
(1) There are no operation errors associated with the UDCNT2 instruction.
[Program Example]
(1) The following program performs a count operation as instructed by C0 (count up or down) on
the status of X0 and X1 after X20 has gone ON.
[Ladder Mode] [List Mode]
Steps
Instruction
Device
[Operation]
X0
X20
X1
Present
value of COM
C0 contact
1
0 2345 43210
-1 -2 -1 -1
Artisan Technology Group - Quality Instrumentation ... Guaranteed | (888) 88-SOURCE | www.artisantg.com

Mitsubishi MELSEC QCPU Specifications

General

Model	MELSEC QCPU
Series	Q Series
Category	Controller
Memory	Varies depending on CPU type
Program Memory	Varies depending on CPU type (e.g., 32K steps to 260K steps or more)
Data Memory	Varies depending on CPU type (e.g., 64K words to 512K words)
I/O Capacity	Up to 4096 points (varies by model)
Number of I/O Points	Up to 4096 points
Communication	Ethernet
Programming Language	Ladder Logic, Instruction List, SFC, ST, Function Block Diagram
Program Capacity	Varies depending on CPU type (e.g., 32K steps to 260K steps or more)
Power Supply	24V DC or 100-240V AC (depending on model)
Operating Temperature	0°C to 55°C
Storage Temperature	-25°C to 75°C
Humidity	5 to 95% RH, non-condensing
Shock Resistance	147 m/s2, 3 times in X, Y, and Z directions

Summary

SAFETY PRECAUTIONS

REVISIONS

GENERAL DESCRIPTION

Related Programming Manuals

Lists other relevant programming manuals.

Abbreviation and Generic Name

Explains abbreviations and generic names used.

INSTRUCTION TABLES

Types of Instructions

Categorizes the types of CPU module instructions.

How to Read Instruction Tables

Explains the format and conventions of instruction tables.

Sequence Instructions

Instructions for relay control ladders.

Basic Instructions

Common operations like comparison and arithmetic.

Application Instructions

Instructions for specific applications like logical operations.

Instructions for Data Link

Instructions for data communication between stations.

QCPU Instructions

Instructions specific to QCPU modules.

Redundant System Instructions (For Q4ARCPU)

Instructions for redundant system configuration.

CONFIGURATION OF INSTRUCTIONS

Configuration of Instructions

Explains the structure of CPU module instructions.

Designating Data

Describes how to designate data types for instructions.

Index Modification

Explains how to use index registers for indirect addressing.

Indirect Designation

Explains how to use indirect addressing for devices.

Subset Processing

Explains subset processing for performance improvement.

Cautions on Programming (Operation Errors)

Describes programming cautions and potential operation errors.

Conditions for Execution of Instructions

Explains different execution conditions for instructions.

Counting Step Number

Explains how step numbers are calculated for instructions.

Operation when OUT, SET/RST, or PLS/PLF Instructions Use the Same Device

Explains behavior when multiple instructions use the same device.

HOW TO READ INSTRUCTIONS

How to Read Instructions

Explains how to read instruction descriptions.

SEQUENCE INSTRUCTIONS

Contact Instructions

Instructions for operation start and connections.

Connection Instructions

Instructions for connecting ladder blocks.

Operation results push, read, pop (MPS, MRD, MPP)

Instructions for managing operation results.

Timers (OUT T, OUTH T)

Instructions for low and high speed timers.

Counters (OUT C)

Instructions for up/down counters.

Setting devices (except for annunciators) (SET)

Instruction to set devices ON.

Resetting devices (except for annunciators) (RST)

Instruction to reset devices OFF.

Leading edge and trailing edge output (PLS, PLF)

Instructions for pulse output on leading/trailing edges.

Shift Instruction

Instructions for shifting bit devices.

Master Control Instructions

Instructions for master control of program execution.

Termination Instructions

Instructions to terminate program execution.

Other Instructions

Miscellaneous instructions.

BASIC INSTRUCTIONS

Comparison Operation Instruction

Instructions for comparing data.

Arithmetic Operation Instructions

Instructions for addition, subtraction, multiplication, division.

Data Conversion Instructions

Instructions for converting data formats.

Data Transfer Instructions

Instructions for moving data.

Program Execution Control Instructions

Instructions to control program execution flow.

Other Convenient Instructions

Various useful instructions.

APPENDICES

APPENDIX1 OPERATION PROCESSING TIME

Details processing times for various CPU modules.

APPENDIX 2 COMPARISON OF PERFORMANCE BETWEEN CPUs

Compares performance across different CPU types.

APPENDIX 3 SPECIAL RELAY LIST

Lists and explains special relays.

APPENDIX 4 SPECIAL REGISTER LIST

Lists and explains special registers.

APPENDIX 5 APPLICATION PROGRAM EXAMPLES

Provides examples of application programs.