Mitsubishi Electronics FX1S manual 20 End, Program scan

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FX Series Programmable Controllers

Basic Program Instructions 2

2.20End

FX1S

FX1N

FX2N

FX2NC


	Mnemonic	Function		Format				Devices	Program steps
	END	Forces the current
		Forces the current
		program scan to			END			N/A	1
	(END)

		end
		end

Basic points to remember:

-Placing an END instruction in a program forces that program to end the current scan and carry out the updating processes for both inputs and outputs.

-Inserting END instructions in the middle of the program helps program debugging as the section after the END instruction is disabled and isolated from the area that is being checked. Remember to delete the END instructions from the blocks which have already been checked.

-When the END instruction is processed the PLCs watchdog timer is automatically refreshed.

A program scan:

• A program scan is a single processing of the loaded program from start to finish, This includes updating all inputs, outputs and watchdog timers. The time period for one such process to occur is called the scan time. This will be dependent upon program length and complexity. Immediately the current scan is completed the next scan begins. The whole process is a continuous cycle. Updating of inputs takes place at the beginning of each scan while all outputs are updated at the end of the scan.

2-23

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Contents Programming Manual Page Foreword FX Series Programmable ControllersFX Series Programmable Controllers FAX Back Combined Programming Manual J FX Series Programmable Controllers Software Warnings Hardware WarningsFX 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 Overview IntroductionWhat do You Need to Program a PLC? What is a Programmable Controller?Current Generation CPU all versions Special considerations for programming equipmentManual name Number FX Base Unit Hardware Assocciated ManualsManual name Number FX DU, GOT and DM units Memo Basic Program Instructions FX Series Programmable ControllersBasic Program Instructions Outline of Basic Devices Used in Programming What is a Program?Detailed device information Example How to Read Ladder LogicOUT instruction Load, Load InverseProgram example Out Timer and Counter VariationsLast coil effect Use of dual coilsDouble Coil Designation Peripheral limitations And, And InverseORI Or, Or InverseSingle Operation flags M2800 to M3071 Load Pulse, Load Trailing PulseLDF ANF OUT Pulse, And Trailing PulseORF ORB Or Pulse, Or Trailing PulseBatch processing limitations Or BlockSequential processing limitations ANB BlockMPS, MRD and MPP usage 13 MPS, MRD and MPPMultiple program examples MCR Master Control and ResetNested MC program example Resetting timers and counters Set and ResetRetentive timers Timer, Counter Out & Reset16.1Basic Timers, Retentive Timers And Counters Availability of devices Bit countersNormal 32 bit Counters High Speed CountersLeading and Trailing Pulse PLFUsages for INV InverseNo Operation No OperationProgram scan 20 EndMemo STL Programming FX Series Programmable ControllersSTL Programming General note What is STL, SFC And IEC1131 Part 3?Each step is a program How STL OperatesLook Inside an STL Combined SFC Ladder representation How To Start And End An STL ProgramEmbedded STL programs Activating new statesTerminating an STL Program Initial StepsReturning to Standard Ladder Moving Between STL Steps Using SET to drive an STL coilOUT is used for loops and jumps Using OUT to drive an STL coilOut is used for distant jumps Basic Notes On The Behavior Of STL programs Rules and Techniques For STL programsT001 K20 K50 Method 1 Using locking devices Single Signal Step ControlMethod 2 Special Single Pulse Flags Using ‘jump’ operations with STL Restrictions Of Some Instructions When Used With STLRestrictions on using applied instructions STL OUT SET Using STL To Select The Most Appropriate ProgramLimits on the number of branches Using STL To Activate Multiple Flows SimultaneouslyLimits on the number of branches Instruction Format General Rules For Successful STL BranchingGeneral Precautions When Using The FX-PCS/AT-EE Software Simple STL Flow Programming ExamplesSET STL Identification of normally closed contactsSelective Branch/ First State Merge Example Program Points to noteFull STL flow diagram/program Advanced STL Use Devices in Detail FX Series Programmable ControllersDevices in Detail Inputs Configuration detailsAvailable devices Device MnemonicDevice Mnemonic Y OutputsAlias O/P Device Mnemonic M Auxiliary RelaysGeneral Stable State Auxiliary Relays External loads Battery Backed/ Latched Auxiliary RelaysSpecial Single Operation Pulse Relays Special Diagnostic Auxiliary RelaysDevice Mnemonic S State RelaysGeneral Stable State State Relays PLC FX 1S FX 1N FX 2N Battery Backed/ Latched State RelaysMonitoring STL programs Assigned statesSTL/SFC programming IST instructionAnnunciator Flags Jumping to the end of the program PointersDevice availability Device Mnemonic PAdditional applied instructions Interrupt PointersNested levels Pointer positionRules of use Timer InterruptsInput Interrupts Disabling high speed counter interrupts Driving special auxiliary relaysAdditional notes Disabling Individual InterruptsConstant H Constant KDevice Mnemonic K Example device usage N/ATimer accuracy TimersDevice Mnemonic T Selectable Timers General timer operationDriving special auxiliary coils Retentive Timers Using timers in interrupt or ‘CALL’ subroutinesTimers Used in Interrupt and ‘CALL’ Subroutines Internal timer accuracyTimer Accuracy ConditionCounters Setting ranges for countersHigh speed counters Device Mnemonic CGeneral/ Latched 16bit UP Counters Battery backed/latched countersSelecting the counting direction Battery backed/ latched countersGeneral/ Latched 32bit Bi-directional Counters Further uses None Basic high speed counter operationBasic High Speed Counter Operation Driving high speed counter coilsCounter Speeds Input assignmentAvailability of High Speed Counters Calculating the maximum combined counting speed on FX1S Setting range Device specificationDirection setting Using the SPD instructionRST Device size 11.5 2 Phase Bi-directional Counters C246 to C25011.6 A/B Phase Counters C252 to C255 Device Mnemonic D Data RegistersExample device usage None Data retention Data register updatesGeneral Use Registers Use of diagnostic registers Using the FX2-40AW/APBattery Backed/ Latched Registers Special Diagnostic RegistersWriting to file registers Special caution when using FX1SFile Registers Program memory registersUses Externally Adjusted RegistersUse of Modifiers with Applied Instruction Parameters Index RegistersDevice Mnemonic V,Z Available formsModifying a Constant Using Multiple Index RegistersMisuse of the Modifiers Bit Devices, Individual and Grouped Bits, Words, BCD and HexadecimalAssigning I/O Moving grouped bit devicesAssigning grouped bit devices Interpreting Word Data Word DevicesFX Series Programmable Controllers Word Data Summary Binary Coded Decimal value= ErrorInverted7 Additional1 14.4 Two’s ComplimentSome useful constants Floating Point And Scientific NotationScientific Notation Floating Point Format FLT