Mitsubishi Electronics FX1S Driving high speed counter coils, Basic High Speed Counter Operation

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FX Series Programmable Controllers

Devices in Detail 4

4.11.1Basic High Speed Counter Operation

Although counters C235 to C255 (21 points) are all high speed counters, they share the same range of high speed inputs. Therefore, if an input is already being used by a high speed counter, it cannot be used for any other high speed counters or for any other purpose, i.e as an interrupt input.

The selection of high speed counters are not free, they are directly dependent on the type of counter required and which inputs are available.

Available counter types;

a)1 phase with user start/reset: C235 to C240

b)1 phase with assigned start/reset: C241 to C245

c)2 phase bi-directional: C246 to C250

d)A/B phase type: C251 to C255

Please note ALL of these counters are 32bit devices.

High speed counters operate by the principle of interrupts. This means they are event triggered and independent of cycle time. The coil of the selected counter should be driven continuously to indicate that this counter and its associated inputs are reserved and that other high speed processes must not coincide with them.

Example:

When X20 is ON, high speed counter C235 is selected. The counter C235 corresponds to count input X0. X20 is NOT the counted signal. This is the continuous drive mentioned earlier. X0 does not have to be included in the program. The input assignment is hardware related and cannot be changed by the user.

X20

C235

 

X20

K4789

 

C236

 

D4

When X20 is OFF, coil C235 is turned OFF and coil C236 is turned ON. Counter C236 has an assigned input of X1, again the input X20 is NOT the counted input.

The assignment of counters and input devices is dependent upon the PLC selected. This is explained in the relevant, later sections.

Driving high speed counter coils:

• The counted inputs are NOT used to

 

 

 

 

 

 

 

 

 

 

 

 

 

 

drive the high speed counter coils.

 

X0

 

 

 

 

 

 

 

This is because the counter coils

 

C235

 

 

 

 

 

 

 

 

 

 

 

 

 

 

need to be continuously driven ON

 

X1

K4789

 

to reserve the associated high speed

 

 

 

 

 

 

C236

 

 

inputs.

 

 

 

 

 

 

 

 

 

 

D4

 

Therefore, a normal non-high speed

 

 

 

 

 

 

 

 

 

 

 

 

drive contact should be used to drive the high speed counter coil.

Ideally the special auxiliary contact M8000 should be used. However, this is not compulsory.

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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
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