Mitsubishi Electronics FX1S manual How To Start And End An STL Program, Embedded STL programs

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FX Series Programmable Controllers

STL Programming 3

Combined SFC Ladder representation

Sometimes STL programs will be written in hard copy as a combination of both flow diagram and internal sub-program. (example shown below).

Identification of contact states

•Please note the following convention is used:

Normally Open contact

Normally Closed contact

Common alternatives are ‘a’ and ‘b’ i d e n t i f i e r s f o r N o r m a l ly O p e n , Normally Closed states or often a line drawn over the top of the Normally Closed contact name is used, e.g. X000.

M8002

S 0

X0

X1

S 22

T0

S 27

T7

Y20

X0

X1

Y22	S 26

T0

K20

X15

Y27

T7

K20

Y26

3.3How To Start And End An STL Program

Before any complex programming can be undertaken the basics of how to start and more importantly how to finish an STL program need to be examined.

3.3.1Embedded STL programs

An STL style program does not have to entirely replace a standard ladder logic program. In fact it might be very difficult to do so. Instead small or even large section of STL program can be entered at any point in a program . Once the STL task has been completed the program must go back to processing standard program instructions until the next STL program block. Therefore, identifying the start and end of an STL program is very important.

3.3.2Activating new states

LD X000

OUT Y004

LD X002

SET S009

STL S009

OUT Y010

LDI X003

OUT Y006 RET

LD X005

OUT Y007

RST M080

Normal Ladder Program

Embedded STL Program

Once an STL step has been selected, how is it used and how is the program ‘driven’?

This is not so difficult, if it is considered that for an STL step to be active its associated state coil must be ON. Hence, to start an STL sequence all that has to be done is to drive the relevant state ON.

There are many different methods to drive a state, for example the initial state coils could be pulsed, SET or just included in an OUT instruction. However, within Mitsubishi’s STL programming language an STL coil which is SET has a different meaning than one that is included in an OUT instruction.

	STL	Y22
	S 22	Y22
	S 22	K20
		K20
		T0
	T0
	SET	S 27
	STL
	S 27

Note: For normal STL operation it is recommended that the states are selected using the SET instruction. To activate an STL step its state coil is SET ON.

3-3

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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