Mitsubishi Electronics FX1S manual Use of dual coils, Last coil effect, Double Coil Designation

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FX Series Programmable Controllers

Basic Program Instructions 2

2.5.2Double Coil Designation

1.

X1

Y3

Y3

Y4 2.

X2

Y3

Double or dual coiling is not a recommended practice. Using multiple output coils of the s a m e d e v i c e c a n c a u s e t h e p r o g r a m operation to become unreliable. The example program shown opposite identifies a double coil situation; there are two Y3 outputs. The following sequence of events will occur when inputs X1 = ON and X2 = OFF;

1.The first Y3 tuns ON because X1 is ON. The contacts associated with Y3 also energize when the coil of output Y3 energizes. Hence, output Y4 turns ON.

2.The last and most important line in this program looks at the status of input X2.

If this is NOT ON then the second Y3 coil does NOT activate. Therefore the status of the Y3 coil updates to reflect this new situation, i.e. it turns OFF. The final outputs are then Y3 = OFF and Y4 = ON.

Use of dual coils:

•Always check programs for incidents of dual coiling. If there are dual coils the program will not operate as expected - possibly resulting in physical damage.

The last coil effect:

•In a dual coil designation, the coil operation designated last is the effective coil. That is, it is the status of the previous coil that dictates the behavior at the current point in the program.

1	t secs	2	3
	4	4
	5	7
	6	7

: Input ON state NOT recognized

: Input ON state recognized

: Input OFF state NOT recognized

: 1 program processing

: Input processing

: Output processing

: A full program scan/operation cycle

Input durations:

The ON or OFF duration of the PLC inputs must be longer than the operation cycle time of the PLC.

Taking a 10 msec (standard input filter) response delay into account, the ON/OFF duration must be longer than 20 msec if the operation cycle (scan time) is 10 msec.

Therefore, in this example, input pulses of more than 25Hz (1sec/(20msec ON + 20msec OFF)) cannot be sensed.

There are applied instructions provided to handle such high speed input requests.

2-5

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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 High Speed Counters Bit countersAvailability of devices Normal 32 bit 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 Activating new states How To Start And End An STL ProgramCombined SFC Ladder representation Embedded STL programsTerminating 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 Device Mnemonic Configuration detailsInputs Available devicesDevice 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 RelaysIST instruction Assigned statesMonitoring STL programs STL/SFC programmingAnnunciator Flags Device Mnemonic P PointersJumping to the end of the program Device availabilityPointer position Interrupt PointersAdditional applied instructions Nested levelsRules of use Timer InterruptsInput Interrupts Disabling Individual Interrupts Driving special auxiliary relaysDisabling high speed counter interrupts Additional notesExample device usage N/A Constant KConstant H Device Mnemonic KTimer accuracy TimersDevice Mnemonic T Selectable Timers General timer operationDriving special auxiliary coils Retentive Timers Using timers in interrupt or ‘CALL’ subroutinesCondition Internal timer accuracyTimers Used in Interrupt and ‘CALL’ Subroutines Timer AccuracyDevice Mnemonic C Setting ranges for countersCounters High speed countersGeneral/ 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 Using the SPD instruction Device specificationSetting range Direction settingRST 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 Special Diagnostic Registers Using the FX2-40AW/APUse of diagnostic registers Battery Backed/ Latched RegistersProgram memory registers Special caution when using FX1SWriting to file registers File RegistersUses Externally Adjusted RegistersAvailable forms Index RegistersUse of Modifiers with Applied Instruction Parameters Device Mnemonic V,ZModifying 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