What is a Programmable Controller? | Mitsubishi Electronics FX1S

Introduction 1

1.2What is a Programmable Controller?

FX1S

FX1N

FX2N

FX2NC

A Programmable Logic Controller (PLC or programmable controller) is a device that a user can program to perform a series or sequence of events. These events are triggered by stimuli (usually called inputs) received at the PLC or through delayed actions such as time delays or counted occur-rences. Once an event triggers, it actuates in the outside world by switching ON or OFF electronic control gear or the physical actuation of devices. A programmable controller will continually ‘loop’ through its internal ‘user defined’ program waiting for inputs and giving outputs at the programmed specific times.

Note on terminology:

The term programmable controller is a generic word used to bring all the elements making the control system under one descriptive name. Sometimes engineers use the term ‘Programmable Logic Controller’, ‘PLC’ or ‘programmable controller’ to describe the same control system.

The construction of a programmable controller can be broken down into component parts. The element where the program is loaded, stored and processed is often known as the Main Processing Unit or MPU. Other terms commonly heard to describe this device are ‘base unit’, ‘controller’ and ‘CPU’. The term CPU is a little misleading as todays more advanced products may contain local CPU devices. A Main CPU (or more correctly a Main Processing Unit) controls these local CPUs through a communication network or bus.

1.3What do You Need to Program a PLC?

FX1S

FX1N

FX2N

FX2NC

A variety of tools are available to program the Mitsubishi FX family of PLCs. Each of these tools can use and access the instructions and devices listed in this manual for the identified PLC.

HPP

FX-10P-E FX-20P-E

FX1S

FX1N

FX2N

FX2NC

Opto-isolated

RS232/

RS422 interface

Personal computer

Melsec MEDOC

Melsec Medoc Plus

SW1PC-FXGPEE

FX-PCS-WIN-E

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Mitsubishi Electronics FX1S manual What is a Programmable Controller?, What do You Need to Program a PLC?

Contents

Programming Manual Page FX Series Programmable Controllers Foreword FX Series Programmable Controllers FAX Back Combined Programming Manual J FX Series Programmable Controllers Hardware Warnings Software Warnings FX Series Programmable Controllers Contents STL Programming Applied Instructions Rotation And Shift Functions 30 to External FX Serial Devices Functions 80 to Execution Times And Instructional 10-1 Viii FX Series Programmable Controllers Chapter Contents Introduction Overview What is a Programmable Controller? What do You Need to Program a PLC? Special considerations for programming equipment Current Generation CPU all versions Assocciated Manuals Manual name Number FX Base Unit Hardware Manual name Number FX DU, GOT and DM units Memo Basic Program Instructions FX Series Programmable ControllersBasic Program Instructions Detailed device information What is a Program?Outline of Basic Devices Used in Programming How to Read Ladder Logic Example Program example Load, Load InverseOUT instruction Timer and Counter Variations Out Double Coil Designation Use of dual coilsLast coil effect And, And Inverse Peripheral limitations Or, Or Inverse ORI Load Pulse, Load Trailing Pulse Single Operation flags M2800 to M3071 Pulse, And Trailing Pulse LDF ANF OUT Or Pulse, Or Trailing Pulse ORF ORB Sequential processing limitations Or BlockBatch processing limitations Block ANB 13 MPS, MRD and MPP MPS, MRD and MPP usage Multiple program examples Master Control and Reset MCR Nested MC program example Set and Reset Resetting timers and counters 16.1Basic Timers, Retentive Timers And Counters Timer, Counter Out & ResetRetentive timers Bit counters Availability of devicesNormal 32 bit Counters High Speed Counters PLF Leading and Trailing Pulse Inverse Usages for INV No Operation No Operation 20 End Program scan Memo STL Programming FX Series Programmable ControllersSTL Programming What is STL, SFC And IEC1131 Part 3? General note Look Inside an STL How STL OperatesEach step is a program How To Start And End An STL Program Combined SFC Ladder representationEmbedded STL programs Activating new states Returning to Standard Ladder Initial StepsTerminating an STL Program Using SET to drive an STL coil Moving Between STL Steps Out is used for distant jumps Using OUT to drive an STL coilOUT is used for loops and jumps Rules and Techniques For STL programs Basic Notes On The Behavior Of STL programs T001 K20 K50 Method 2 Special Single Pulse Flags Single Signal Step ControlMethod 1 Using locking devices Restrictions on using applied instructions Restrictions Of Some Instructions When Used With STLUsing ‘jump’ operations with STL Using STL To Select The Most Appropriate Program STL OUT SET Using STL To Activate Multiple Flows Simultaneously Limits on the number of branches Limits on the number of branches General Rules For Successful STL Branching Instruction Format General Precautions When Using The FX-PCS/AT-EE Software Programming Examples Simple STL Flow Identification of normally closed contacts SET STL Points to note Selective Branch/ First State Merge Example Program Full STL flow diagram/program Advanced STL Use Devices in Detail FX Series Programmable ControllersDevices in Detail Configuration details InputsAvailable devices Device Mnemonic Alias O/P OutputsDevice Mnemonic Y General Stable State Auxiliary Relays Auxiliary RelaysDevice Mnemonic M Battery Backed/ Latched Auxiliary Relays External loads Special Diagnostic Auxiliary Relays Special Single Operation Pulse Relays General Stable State State Relays State RelaysDevice Mnemonic S Battery Backed/ Latched State Relays PLC FX 1S FX 1N FX 2N Assigned states Monitoring STL programsSTL/SFC programming IST instruction Annunciator Flags Pointers Jumping to the end of the programDevice availability Device Mnemonic P Interrupt Pointers Additional applied instructionsNested levels Pointer position Input Interrupts Timer InterruptsRules of use Driving special auxiliary relays Disabling high speed counter interruptsAdditional notes Disabling Individual Interrupts Constant K Constant HDevice Mnemonic K Example device usage N/A Device Mnemonic T TimersTimer accuracy Driving special auxiliary coils General timer operationSelectable Timers Using timers in interrupt or ‘CALL’ subroutines Retentive Timers Internal timer accuracy Timers Used in Interrupt and ‘CALL’ SubroutinesTimer Accuracy Condition Setting ranges for counters CountersHigh speed counters Device Mnemonic C Battery backed/latched counters General/ Latched 16bit UP Counters General/ Latched 32bit Bi-directional Counters Battery backed/ latched countersSelecting the counting direction Basic high speed counter operation Further uses None Driving high speed counter coils Basic High Speed Counter Operation Availability of High Speed Counters Input assignmentCounter Speeds Calculating the maximum combined counting speed on FX1S Device specification Setting rangeDirection setting Using the SPD instruction RST 11.5 2 Phase Bi-directional Counters C246 to C250 Device size 11.6 A/B Phase Counters C252 to C255 Example device usage None Data RegistersDevice Mnemonic D General Use Registers Data register updatesData retention Using the FX2-40AW/AP Use of diagnostic registersBattery Backed/ Latched Registers Special Diagnostic Registers Special caution when using FX1S Writing to file registersFile Registers Program memory registers Externally Adjusted Registers Uses Index Registers Use of Modifiers with Applied Instruction ParametersDevice Mnemonic V,Z Available forms Misuse of the Modifiers Using Multiple Index RegistersModifying a Constant Bits, Words, BCD and Hexadecimal Bit Devices, Individual and Grouped Assigning grouped bit devices Moving grouped bit devicesAssigning I/O Word Devices Interpreting Word Data FX Series Programmable Controllers Binary Coded Decimal value= Error Word Data Summary 14.4 Two’s Compliment Inverted7 Additional1 Floating Point And Scientific Notation Some useful constants Scientific Notation Floating Point Format FLT