769 lines
45 KiB
Plaintext
769 lines
45 KiB
Plaintext
(*═══════════════════════════════════════════════════════════════════════════════
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FB_WeldSequencer
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S7-1500 SCL — 10-Step Robotic Welding Cell Sequencer
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TIA Portal V18+ | Optimized Block Access
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─────────────────────────────────────────────────────────────────────────────
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APPLICATION: MIG/MAG Welding Cell — Clamp → Weld → Release cycle
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─────────────────────────────────────────────────────────────────────────────
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MODES:
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AUTO — Steps advance automatically the moment advance condition is met
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INCR — Operator must press Cmd_Incr AFTER advance condition is TRUE
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(used for commissioning, fault recovery, or slow-speed prove-out)
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SEQUENCER STATES (SeqState output INT):
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0 = IDLE Waiting for Start command
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1 = RUNNING Sequence actively executing
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2 = PAUSED Outputs held; resumes from same step on Cmd_Start
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3 = STOPPING_CAT1 Controlled stop: current step finishes then halts
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4 = STOPPED CAT1/CAT2 halt complete; Reset required
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5 = FAULTED Hard fault; safety interlock; Reset + clear required
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6 = COMPLETE All 10 steps done; awaiting restart or Reset
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STOP CATEGORIES (IEC 60204-1):
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CAT0 Immediate: ALL outputs de-energised instantly
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Trigger: Cmd_EStop = TRUE AND StopCategory = 0
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CAT1 Controlled: current step completes its "safe motion" then stops.
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A 10 s timeout (CAT1_TIMEOUT) guards against stuck conditions.
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Trigger: Cmd_EStop = TRUE AND StopCategory = 1
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CAT2 Suspend & hold: outputs frozen at current state until Reset
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Trigger: Cmd_Stop (always CAT2)
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Cmd_EStop = TRUE AND StopCategory = 2
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PAUSE vs STOP:
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PAUSE — Soft, temporary. Cmd_Pause latches PAUSED state. All outputs held.
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Cmd_Start resumes from same step / same position.
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Safety interlock (door open) will NOT allow resume.
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STOP — CAT2 permanent hold. Requires Cmd_Reset to return to IDLE.
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Typically used for planned end-of-shift or material change.
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STEP FEATURES:
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_stepEnabled[N] = FALSE → step is silently skipped every cycle
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_stepSafetyLocked[N] = TRUE → operator Cmd_SkipStep is ignored
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Cmd_SkipStep (rising edge) → forces advance on UN-locked steps only
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_stepUseTimer[N] = TRUE → advance on timer expiry (no sensor required)
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_stepTimerPreset[N] → IEC time preset for timer steps
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FAULT CODES (FaultCode output INT):
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0 No fault
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10 Safety door opened during run / pause
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11 E-Stop activated (CAT0/1/2 determined by StopCategory)
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20 CAT1 controlled-stop timeout (step overran CAT1_TIMEOUT)
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30 Sensor conflict: FWD + BWD sensors simultaneously TRUE
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40 Step watchdog timeout: step did not complete in WATCHDOG_TIME
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I/O SUMMARY — WELDING CELL:
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┌──────┬──────────────────────────┬──────────────┬────────────────────────────┐
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│ Step │ Name │ Advance │ Sensors / Timers │
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├──────┼──────────────────────────┼──────────────┼────────────────────────────┤
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│ 1 │ Home Position Verify │ 2 Sensors │ Sen_HomeFwd + NOT HomeBwd │
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│ 2 │ Clamp Workpiece │ 1 Sensor │ Sen_ClampClosed │
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│ 3 │ Extend Weld Head │ 1 Sensor FWD │ Sen_HeadAtWeldPos (FWD) │
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│ │ │ (2 declared) │ Sen_HeadRetracted (BWD) │
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│ 4 │ Pre-Purge Gas │ Timer 2.0 s │ None │
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│ 5 │ Arc Strike │ 1 Sensor │ Sen_ArcDetect 🔒LOCKED │
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│ 6 │ Weld Travel │ Timer 4.0 s │ None │
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│ 7 │ Arc Off / Weld End │ 1 Sensor │ Sen_ArcOff 🔒LOCKED │
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│ 8 │ Post-Purge Gas │ Timer 2.5 s │ None │
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│ 9 │ Retract Weld Head │ 1 Sensor BWD │ Sen_HeadRetracted (BWD) │
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│ │ │ (2 declared) │ Sen_HeadAtWeldPos (FWD) │
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│ 10 │ Unclamp / Part Eject │ 1 Sensor │ Sen_UnclampConf │
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└──────┴──────────────────────────┴──────────────┴────────────────────────────┘
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🔒 Safety-locked: Step 1 (home verify), Step 5 (arc confirm), Step 7 (arc off)
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═══════════════════════════════════════════════════════════════════════════════*)
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FUNCTION_BLOCK "FB_WeldSequencer"
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{ S7_Optimized_Access := 'TRUE' }
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VERSION : 0.1
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VAR_INPUT
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//── MODE SELECTION ──────────────────────────────────────────────────────
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Mode_Auto : Bool; // TRUE = Automatic continuous advance
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Mode_Incr : Bool; // TRUE = Increment step-by-step mode
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//── OPERATOR COMMANDS (all rising-edge triggered unless noted) ──────────
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Cmd_Start : Bool; // Start cycle / Resume after Pause
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Cmd_Pause : Bool; // Pause: hold outputs, resume same step
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Cmd_Stop : Bool; // CAT2 Stop: hold & require Reset
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Cmd_EStop : Bool; // E-Stop: level signal (TRUE = activated)
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Cmd_Reset : Bool; // Clear fault / return to IDLE
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Cmd_Incr : Bool; // Increment next step (INCR mode only)
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Cmd_SkipStep : Bool; // Skip current step if not safety-locked
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StopCategory : Int; // E-Stop category: 0=CAT0, 1=CAT1, 2=CAT2
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//── SAFETY MONITORING ───────────────────────────────────────────────────
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Safety_DoorClosed : Bool; // Safety gate (NC contact, TRUE = closed/safe)
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Safety_EStopOK : Bool; // Safety relay feedback (TRUE = no E-Stop)
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//── PROCESS SENSORS (DI) ────────────────────────────────────────────────
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// STEP 1 — Home Position [2 sensors]
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Sen_HomeFwd : Bool; // Fixture confirmed at home position
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Sen_HomeBwd : Bool; // Fixture NOT in work zone (interlock sensor)
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// STEP 2 — Clamp [1 sensor]
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Sen_ClampClosed : Bool; // Clamp jaw fully closed on part
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// STEP 3 + 9 — Weld Head [2 sensors: FWD + BWD shared]
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Sen_HeadAtWeldPos : Bool; // Head fully EXTENDED to weld start position
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Sen_HeadRetracted : Bool; // Head fully RETRACTED to safe position
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// STEP 5 — Arc Strike [1 sensor]
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Sen_ArcDetect : Bool; // Welding arc current detected (TRUE = arc ON)
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// STEP 7 — Arc Off [1 sensor]
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Sen_ArcOff : Bool; // Arc current extinguished (TRUE = arc OFF)
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// STEP 10 — Unclamp [1 sensor]
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Sen_UnclampConf : Bool; // Clamp fully open / part cleared
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END_VAR
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VAR_OUTPUT
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//── ACTUATORS (DQ) ──────────────────────────────────────────────────────
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Act_Clamp : Bool; // Step 2–9: Clamp solenoid (energise = clamp)
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Act_HeadExtend : Bool; // Step 3–8: Weld head extend solenoid
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Act_HeadRetract : Bool; // Step 9: Weld head retract solenoid
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Act_GasValve : Bool; // Step 4–8: Shielding gas solenoid valve
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Act_WeldEnable : Bool; // Step 5–6: Welder power enable
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Act_Unclamp : Bool; // Step 10: Unclamp solenoid
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Act_PartEject : Bool; // Step 10: Part ejector cylinder
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//── SEQUENCER STATUS ────────────────────────────────────────────────────
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Seq_Idle : Bool; // State = IDLE
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Seq_Running : Bool; // State = RUNNING
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Seq_Paused : Bool; // State = PAUSED
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Seq_Stopping : Bool; // State = STOPPING_CAT1
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Seq_Stopped : Bool; // State = STOPPED
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Seq_Faulted : Bool; // State = FAULTED
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Seq_Complete : Bool; // State = COMPLETE
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ActiveStep : Int; // Currently executing step (0 = none)
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SeqState : Int; // Numeric state code (see header)
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FaultCode : Int; // Active fault code (0 = no fault)
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StepAdvanceReady : Bool; // TRUE when advance condition is satisfied
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IncrWaiting : Bool; // TRUE in INCR mode, condition met, waiting Incr
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CycleCount : DInt; // Completed cycle counter (persistent)
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END_VAR
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VAR
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//── INTERNAL STATE ──────────────────────────────────────────────────────
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_state : Int; // Sequencer state machine current state
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_activeStep : Int; // Active step number (1..10, 0=none)
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_stepAdvReady : Bool; // Advance condition for current step
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//── STEP CONFIGURATION ARRAYS [1..10] ───────────────────────────────────
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_stepEnabled : Array[1..10] OF Bool; // FALSE = disabled/skip
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_stepSafetyLocked : Array[1..10] OF Bool; // TRUE = SkipStep ignored
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_stepUseTimer : Array[1..10] OF Bool; // TRUE = timer-based advance
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_stepTimerPreset : Array[1..10] OF Time; // Timer preset (relevant if above)
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//── TIMERS ──────────────────────────────────────────────────────────────
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_stepTimer : Array[1..10] OF TON; // Per-step IEC timer
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_stepWatchdog : Array[1..10] OF TON; // Per-step watchdog timeout
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_cat1Timer : TON; // CAT1 controlled-stop guard timer
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//── EDGE DETECTION (previous scan values) ───────────────────────────────
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_prevStart : Bool;
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_prevPause : Bool;
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_prevStop : Bool;
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_prevReset : Bool;
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_prevIncr : Bool;
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_prevSkip : Bool;
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_prevEStop : Bool;
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//── LATCHED FLAGS ───────────────────────────────────────────────────────
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_incrRequest : Bool; // Latched: set on rising Cmd_Incr edge
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_cat1InProgress : Bool; // TRUE during CAT1 controlled-stop sequence
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_forceAdvance : Bool; // Set by SkipStep to force one advance
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//── MISCELLANEOUS ───────────────────────────────────────────────────────
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_initDone : Bool; // First-scan initialisation flag
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_i : Int; // Loop variable
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END_VAR
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VAR_TEMP
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//── RISING-EDGE PULSES (computed each scan) ─────────────────────────────
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rStart : Bool;
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rPause : Bool;
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rStop : Bool;
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rReset : Bool;
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rIncr : Bool;
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rSkip : Bool;
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rEStop : Bool;
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nextStep : Int; // Working variable for step advance
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END_VAR
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VAR CONSTANT
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//── STATE CONSTANTS ─────────────────────────────────────────────────────
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STATE_IDLE : Int := 0;
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STATE_RUNNING : Int := 1;
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STATE_PAUSED : Int := 2;
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STATE_STOPPING_CAT1 : Int := 3;
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STATE_STOPPED : Int := 4;
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STATE_FAULTED : Int := 5;
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STATE_COMPLETE : Int := 6;
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//── SEQUENCE LIMITS ─────────────────────────────────────────────────────
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FIRST_STEP : Int := 1;
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LAST_STEP : Int := 10;
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//── TIMING CONSTANTS ────────────────────────────────────────────────────
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CAT1_TIMEOUT : Time := T#10S; // Max time for CAT1 controlled stop
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WATCHDOG_TIME : Time := T#30S; // Max time any step may take
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END_VAR
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BEGIN
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(*═══════════════════════════════════════════════════════════════════════════
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░░ S E C T I O N 1 — F I R S T - S C A N I N I T I A L I S A T I O N ░░
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═══════════════════════════════════════════════════════════════════════════*)
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IF NOT _initDone THEN
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FOR _i := 1 TO 10 DO
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_stepEnabled[_i] := TRUE; // All steps ON by default
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_stepSafetyLocked[_i] := FALSE;
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_stepUseTimer[_i] := FALSE;
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_stepTimerPreset[_i] := T#0S;
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END_FOR;
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//── Safety-locked steps (operator Cmd_SkipStep has NO effect) ───────────
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// Step 1: Home verify — must confirm safe start position
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// Step 5: Arc strike — arc MUST be detected before weld travel
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// Step 7: Arc off — arc MUST be extinguished before gas purge ends
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_stepSafetyLocked[1] := TRUE;
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_stepSafetyLocked[5] := TRUE;
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_stepSafetyLocked[7] := TRUE;
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//── Timer-advance steps (no sensor required) ────────────────────────────
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_stepUseTimer[4] := TRUE; _stepTimerPreset[4] := T#2S; // Pre-purge
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_stepUseTimer[6] := TRUE; _stepTimerPreset[6] := T#4S; // Weld travel
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_stepUseTimer[8] := TRUE; _stepTimerPreset[8] := T#2500MS; // Post-purge
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_state := STATE_IDLE;
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_activeStep := 0;
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_initDone := TRUE;
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END_IF;
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(*═══════════════════════════════════════════════════════════════════════════
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░░ S E C T I O N 2 — E D G E D E T E C T I O N ░░
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═══════════════════════════════════════════════════════════════════════════*)
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rStart := Cmd_Start AND NOT _prevStart;
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rPause := Cmd_Pause AND NOT _prevPause;
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rStop := Cmd_Stop AND NOT _prevStop;
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rReset := Cmd_Reset AND NOT _prevReset;
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rIncr := Cmd_Incr AND NOT _prevIncr;
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rSkip := Cmd_SkipStep AND NOT _prevSkip;
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rEStop := Cmd_EStop AND NOT _prevEStop; // Rising edge for event logging
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_prevStart := Cmd_Start;
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_prevPause := Cmd_Pause;
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_prevStop := Cmd_Stop;
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_prevReset := Cmd_Reset;
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_prevIncr := Cmd_Incr;
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_prevSkip := Cmd_SkipStep;
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_prevEStop := Cmd_EStop;
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// Latch increment request — consumed when step actually advances
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IF rIncr THEN
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_incrRequest := TRUE;
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END_IF;
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// Skip step — latch if current step is NOT safety-locked
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IF rSkip AND (_activeStep >= FIRST_STEP) THEN
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IF NOT _stepSafetyLocked[_activeStep] THEN
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_forceAdvance := TRUE;
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END_IF;
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END_IF;
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(*═══════════════════════════════════════════════════════════════════════════
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░░ S E C T I O N 3 — S A F E T Y M O N I T O R I N G ░░
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Evaluated EVERY SCAN and takes priority over state machine
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═══════════════════════════════════════════════════════════════════════════*)
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// ── E-Stop (level-triggered, highest priority) ─────────────────────────
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IF Cmd_EStop OR NOT Safety_EStopOK THEN
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IF NOT _cat1InProgress THEN // Prevent re-entry if already handling
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CASE StopCategory OF
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0: // CAT0 — Immediate de-energise (outputs cleared in Section 6)
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_state := STATE_FAULTED;
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FaultCode := 11;
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1: // CAT1 — Allow current step to reach safe state, then stop
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_cat1InProgress := TRUE;
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_state := STATE_STOPPING_CAT1;
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FaultCode := 11;
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2: // CAT2 — Freeze outputs where they are
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_state := STATE_STOPPED;
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FaultCode := 11;
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ELSE:
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_state := STATE_FAULTED; // Unknown category → safe fault
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FaultCode := 11;
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END_CASE;
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END_IF;
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END_IF;
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// ── Safety door opened while running or paused ─────────────────────────
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IF NOT Safety_DoorClosed THEN
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IF _state = STATE_RUNNING OR _state = STATE_PAUSED THEN
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_state := STATE_FAULTED;
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FaultCode := 10;
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END_IF;
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END_IF;
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// ── Sensor conflict: FWD and BWD sensors both TRUE simultaneously ──────
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IF Sen_HeadAtWeldPos AND Sen_HeadRetracted THEN
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IF _state = STATE_RUNNING OR _state = STATE_STOPPING_CAT1 THEN
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_state := STATE_FAULTED;
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FaultCode := 30;
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END_IF;
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END_IF;
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(*═══════════════════════════════════════════════════════════════════════════
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░░ S E C T I O N 4 — M A I N S T A T E M A C H I N E ░░
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═══════════════════════════════════════════════════════════════════════════*)
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CASE _state OF
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//──────────────────────────────────────────────────────────────────────
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// STATE 0: IDLE — Waiting for Start
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//──────────────────────────────────────────────────────────────────────
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STATE_IDLE:
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_activeStep := 0;
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_cat1InProgress := FALSE;
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_incrRequest := FALSE;
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_forceAdvance := FALSE;
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// Start only if safety circuit is healthy
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IF rStart AND Safety_DoorClosed AND Safety_EStopOK AND (FaultCode = 0) THEN
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// Find first enabled step
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nextStep := FIRST_STEP;
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WHILE nextStep <= LAST_STEP AND NOT _stepEnabled[nextStep] DO
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nextStep := nextStep + 1;
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END_WHILE;
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IF nextStep <= LAST_STEP THEN
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_activeStep := nextStep;
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_state := STATE_RUNNING;
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END_IF;
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END_IF;
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//──────────────────────────────────────────────────────────────────────
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// STATE 1: RUNNING — Sequence executing
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//──────────────────────────────────────────────────────────────────────
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STATE_RUNNING:
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// Pause request
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IF rPause THEN
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_state := STATE_PAUSED;
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END_IF;
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// CAT2 Stop request
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IF rStop THEN
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_state := STATE_STOPPED;
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END_IF;
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// ── Step advance logic ────────────────────────────────────────────
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// Advance condition: sensor/timer TRUE OR forced skip
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IF _stepAdvReady OR _forceAdvance THEN
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_forceAdvance := FALSE;
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// INCR mode: advance condition met — wait for operator Incr
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// AUTO mode: advance immediately
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IF Mode_Incr AND NOT _incrRequest THEN
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// Stay on current step — IncrWaiting will be TRUE (see outputs)
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;
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ELSE
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// Consume the increment request
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_incrRequest := FALSE;
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// Find next enabled step
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nextStep := _activeStep + 1;
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WHILE nextStep <= LAST_STEP AND NOT _stepEnabled[nextStep] DO
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nextStep := nextStep + 1;
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END_WHILE;
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IF nextStep > LAST_STEP THEN
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// All steps complete
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_state := STATE_COMPLETE;
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_activeStep := 0;
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CycleCount := CycleCount + 1;
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ELSE
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_activeStep := nextStep;
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END_IF;
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END_IF;
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END_IF;
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//──────────────────────────────────────────────────────────────────────
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// STATE 2: PAUSED — Outputs held, awaiting resume
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//──────────────────────────────────────────────────────────────────────
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STATE_PAUSED:
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// Resume requires door still closed (re-check safety)
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IF rStart AND Safety_DoorClosed AND Safety_EStopOK THEN
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_state := STATE_RUNNING;
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END_IF;
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IF rStop THEN
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_state := STATE_STOPPED;
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END_IF;
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//──────────────────────────────────────────────────────────────────────
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// STATE 3: STOPPING_CAT1 — Controlled stop; current step finishes
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//──────────────────────────────────────────────────────────────────────
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STATE_STOPPING_CAT1:
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// CAT1 guard timer — prevents infinite hang
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_cat1Timer(IN := TRUE, PT := CAT1_TIMEOUT);
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// Step logic still runs (see Section 5) to allow safe motion to complete
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// Advance to STOPPED when step condition met OR timeout
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IF _stepAdvReady THEN
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_state := STATE_STOPPED;
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_activeStep := 0;
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_cat1InProgress := FALSE;
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_cat1Timer(IN := FALSE, PT := CAT1_TIMEOUT);
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ELSIF _cat1Timer.Q THEN
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// Timeout — step did not complete safely
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FaultCode := 20;
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_state := STATE_FAULTED;
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_cat1InProgress := FALSE;
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_cat1Timer(IN := FALSE, PT := CAT1_TIMEOUT);
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END_IF;
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//──────────────────────────────────────────────────────────────────────
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// STATE 4: STOPPED — Requires Reset to return to IDLE
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//──────────────────────────────────────────────────────────────────────
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STATE_STOPPED:
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// Safe state: weld outputs cleared in Section 6
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IF rReset AND NOT Cmd_EStop AND Safety_EStopOK THEN
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FaultCode := 0;
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_activeStep := 0;
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_state := STATE_IDLE;
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END_IF;
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//──────────────────────────────────────────────────────────────────────
|
||
// STATE 5: FAULTED — Hard stop; all outputs cleared (CAT0 / safety fault)
|
||
//──────────────────────────────────────────────────────────────────────
|
||
STATE_FAULTED:
|
||
// Reset only when E-Stop cleared, door closed, and reset pressed
|
||
IF rReset AND NOT Cmd_EStop AND Safety_EStopOK AND Safety_DoorClosed THEN
|
||
FaultCode := 0;
|
||
_activeStep := 0;
|
||
_state := STATE_IDLE;
|
||
END_IF;
|
||
|
||
//──────────────────────────────────────────────────────────────────────
|
||
// STATE 6: COMPLETE — Cycle finished
|
||
//──────────────────────────────────────────────────────────────────────
|
||
STATE_COMPLETE:
|
||
IF rStart AND Safety_DoorClosed AND Safety_EStopOK THEN
|
||
// Start new cycle
|
||
nextStep := FIRST_STEP;
|
||
WHILE nextStep <= LAST_STEP AND NOT _stepEnabled[nextStep] DO
|
||
nextStep := nextStep + 1;
|
||
END_WHILE;
|
||
IF nextStep <= LAST_STEP THEN
|
||
_activeStep := nextStep;
|
||
_state := STATE_RUNNING;
|
||
END_IF;
|
||
END_IF;
|
||
IF rReset THEN
|
||
_activeStep := 0;
|
||
_state := STATE_IDLE;
|
||
END_IF;
|
||
|
||
END_CASE; // Main state machine
|
||
|
||
(*═══════════════════════════════════════════════════════════════════════════
|
||
░░ S E C T I O N 5 — S T E P E X E C U T I O N ░░
|
||
Outputs built up here. All output vars cleared to FALSE first,
|
||
then each active step energises what it needs.
|
||
This ensures outputs drop when step changes — no "stuck on" risk.
|
||
═══════════════════════════════════════════════════════════════════════════*)
|
||
|
||
// ── Clear all actuator outputs every scan (re-energised by step logic) ──
|
||
Act_Clamp := FALSE;
|
||
Act_HeadExtend := FALSE;
|
||
Act_HeadRetract:= FALSE;
|
||
Act_GasValve := FALSE;
|
||
Act_WeldEnable := FALSE;
|
||
Act_Unclamp := FALSE;
|
||
Act_PartEject := FALSE;
|
||
_stepAdvReady := FALSE;
|
||
|
||
// ── Step logic only active during RUNNING or STOPPING_CAT1 ──────────────
|
||
IF _state = STATE_RUNNING OR _state = STATE_STOPPING_CAT1 THEN
|
||
|
||
IF _activeStep >= FIRST_STEP AND _activeStep <= LAST_STEP THEN
|
||
|
||
//── Per-step timers ─────────────────────────────────────────────────
|
||
// IN driven by (activeStep = this step AND running) — auto-resets on step change
|
||
_stepTimer[1](IN := (_activeStep = 1 AND _state = STATE_RUNNING), PT := _stepTimerPreset[1]);
|
||
_stepTimer[2](IN := (_activeStep = 2 AND _state = STATE_RUNNING), PT := _stepTimerPreset[2]);
|
||
_stepTimer[3](IN := (_activeStep = 3 AND _state = STATE_RUNNING), PT := _stepTimerPreset[3]);
|
||
_stepTimer[4](IN := (_activeStep = 4 AND _state = STATE_RUNNING), PT := _stepTimerPreset[4]);
|
||
_stepTimer[5](IN := (_activeStep = 5 AND _state = STATE_RUNNING), PT := _stepTimerPreset[5]);
|
||
_stepTimer[6](IN := (_activeStep = 6 AND _state = STATE_RUNNING), PT := _stepTimerPreset[6]);
|
||
_stepTimer[7](IN := (_activeStep = 7 AND _state = STATE_RUNNING), PT := _stepTimerPreset[7]);
|
||
_stepTimer[8](IN := (_activeStep = 8 AND _state = STATE_RUNNING), PT := _stepTimerPreset[8]);
|
||
_stepTimer[9](IN := (_activeStep = 9 AND _state = STATE_RUNNING), PT := _stepTimerPreset[9]);
|
||
_stepTimer[10](IN:= (_activeStep = 10 AND _state = STATE_RUNNING), PT := _stepTimerPreset[10]);
|
||
|
||
//── Per-step watchdog timers ─────────────────────────────────────────
|
||
_stepWatchdog[1](IN := (_activeStep = 1), PT := WATCHDOG_TIME);
|
||
_stepWatchdog[2](IN := (_activeStep = 2), PT := WATCHDOG_TIME);
|
||
_stepWatchdog[3](IN := (_activeStep = 3), PT := WATCHDOG_TIME);
|
||
_stepWatchdog[4](IN := (_activeStep = 4), PT := WATCHDOG_TIME);
|
||
_stepWatchdog[5](IN := (_activeStep = 5), PT := WATCHDOG_TIME);
|
||
_stepWatchdog[6](IN := (_activeStep = 6), PT := WATCHDOG_TIME);
|
||
_stepWatchdog[7](IN := (_activeStep = 7), PT := WATCHDOG_TIME);
|
||
_stepWatchdog[8](IN := (_activeStep = 8), PT := WATCHDOG_TIME);
|
||
_stepWatchdog[9](IN := (_activeStep = 9), PT := WATCHDOG_TIME);
|
||
_stepWatchdog[10](IN:= (_activeStep = 10), PT := WATCHDOG_TIME);
|
||
|
||
// Watchdog trip
|
||
IF _stepWatchdog[_activeStep].Q THEN
|
||
FaultCode := 40;
|
||
_state := STATE_FAULTED;
|
||
END_IF;
|
||
|
||
END_IF;
|
||
|
||
//──────────────────────────────────────────────────────────────────────
|
||
CASE _activeStep OF
|
||
|
||
//══════════════════════════════════════════════════════════════════
|
||
// STEP 1 — HOME POSITION VERIFY
|
||
// Purpose : Confirm fixture/robot is at safe home before clamping
|
||
// Actuators: NONE (verify-only step)
|
||
// Sensors : 2 sensors — Sen_HomeFwd (at home) + Sen_HomeBwd (NOT in
|
||
// work zone). BOTH conditions required for safe start.
|
||
// Safety : 🔒 LOCKED — cannot be skipped
|
||
// Advance : Sen_HomeFwd = TRUE AND Sen_HomeBwd = FALSE
|
||
//══════════════════════════════════════════════════════════════════
|
||
1:
|
||
// No outputs energised — pure monitoring step
|
||
_stepAdvReady := Sen_HomeFwd AND NOT Sen_HomeBwd;
|
||
|
||
//══════════════════════════════════════════════════════════════════
|
||
// STEP 2 — CLAMP WORKPIECE
|
||
// Purpose : Close clamp jaw to secure part for welding
|
||
// Actuators: Act_Clamp ON
|
||
// Sensors : 1 sensor — Sen_ClampClosed (clamp jaw closed)
|
||
// Advance : Sen_ClampClosed = TRUE
|
||
//══════════════════════════════════════════════════════════════════
|
||
2:
|
||
Act_Clamp := TRUE;
|
||
_stepAdvReady := Sen_ClampClosed;
|
||
|
||
//══════════════════════════════════════════════════════════════════
|
||
// STEP 3 — EXTEND WELD HEAD TO POSITION
|
||
// Purpose : Drive weld torch to weld-start co-ordinate
|
||
// Actuators: Act_HeadExtend ON
|
||
// Sensors : 2 sensors declared (FWD + BWD shared with Step 9)
|
||
// FWD: Sen_HeadAtWeldPos → advance trigger
|
||
// BWD: Sen_HeadRetracted → conflict / interlock check
|
||
// Advance : Sen_HeadAtWeldPos = TRUE (FWD sensor)
|
||
//══════════════════════════════════════════════════════════════════
|
||
3:
|
||
Act_Clamp := TRUE; // Maintain clamp during all weld steps
|
||
Act_HeadExtend := TRUE;
|
||
_stepAdvReady := Sen_HeadAtWeldPos;
|
||
|
||
//══════════════════════════════════════════════════════════════════
|
||
// STEP 4 — PRE-PURGE GAS (TIMER ADVANCE — no sensor)
|
||
// Purpose : Flow shielding gas before arc strike to purge atmosphere
|
||
// Actuators: Act_GasValve ON
|
||
// Sensors : NONE
|
||
// Advance : Timer T#2S elapsed
|
||
//══════════════════════════════════════════════════════════════════
|
||
4:
|
||
Act_Clamp := TRUE;
|
||
Act_HeadExtend := TRUE;
|
||
Act_GasValve := TRUE;
|
||
_stepAdvReady:= _stepTimer[4].Q;
|
||
|
||
//══════════════════════════════════════════════════════════════════
|
||
// STEP 5 — ARC STRIKE
|
||
// Purpose : Enable welder; wait for arc current confirmation
|
||
// Actuators: Act_WeldEnable ON + Act_GasValve ON
|
||
// Sensors : 1 sensor — Sen_ArcDetect (arc current detected)
|
||
// Safety : 🔒 LOCKED — arc MUST be confirmed before travel
|
||
// Advance : Sen_ArcDetect = TRUE
|
||
//══════════════════════════════════════════════════════════════════
|
||
5:
|
||
Act_Clamp := TRUE;
|
||
Act_HeadExtend := TRUE;
|
||
Act_GasValve := TRUE;
|
||
Act_WeldEnable := TRUE;
|
||
_stepAdvReady := Sen_ArcDetect;
|
||
|
||
//══════════════════════════════════════════════════════════════════
|
||
// STEP 6 — WELD TRAVEL (TIMER ADVANCE — no sensor)
|
||
// Purpose : Weld torch traverses seam (robot/axis handles motion)
|
||
// SCL holds outputs stable for weld duration
|
||
// Actuators: Act_WeldEnable ON + Act_GasValve ON (all weld outputs)
|
||
// Sensors : NONE (robot reports completion via external handshake
|
||
// or fixed weld time used here for demo)
|
||
// Advance : Timer T#4S elapsed
|
||
//══════════════════════════════════════════════════════════════════
|
||
6:
|
||
Act_Clamp := TRUE;
|
||
Act_HeadExtend := TRUE;
|
||
Act_GasValve := TRUE;
|
||
Act_WeldEnable := TRUE;
|
||
_stepAdvReady := _stepTimer[6].Q;
|
||
|
||
//══════════════════════════════════════════════════════════════════
|
||
// STEP 7 — ARC OFF / WELD END
|
||
// Purpose : Command welder off; wait for arc extinction confirmation
|
||
// Actuators: Act_WeldEnable OFF, Act_GasValve ON (gas post-protection)
|
||
// Sensors : 1 sensor — Sen_ArcOff (TRUE = current < threshold)
|
||
// Safety : 🔒 LOCKED — arc MUST be extinguished before any movement
|
||
// Advance : Sen_ArcOff = TRUE
|
||
//══════════════════════════════════════════════════════════════════
|
||
7:
|
||
Act_Clamp := TRUE;
|
||
Act_HeadExtend := TRUE;
|
||
Act_GasValve := TRUE;
|
||
Act_WeldEnable := FALSE; // Welder OFF — waiting for arc to die
|
||
_stepAdvReady := Sen_ArcOff;
|
||
|
||
//══════════════════════════════════════════════════════════════════
|
||
// STEP 8 — POST-PURGE GAS (TIMER ADVANCE — no sensor)
|
||
// Purpose : Continue gas flow after arc off to protect hot weld pool
|
||
// Actuators: Act_GasValve ON
|
||
// Sensors : NONE
|
||
// Advance : Timer T#2.5S elapsed
|
||
//══════════════════════════════════════════════════════════════════
|
||
8:
|
||
Act_Clamp := TRUE;
|
||
Act_HeadExtend := TRUE;
|
||
Act_GasValve := TRUE; // Post-weld purge only — no WeldEnable
|
||
_stepAdvReady := _stepTimer[8].Q;
|
||
|
||
//══════════════════════════════════════════════════════════════════
|
||
// STEP 9 — RETRACT WELD HEAD
|
||
// Purpose : Drive torch back to safe retracted position
|
||
// Actuators: Act_HeadRetract ON, Act_HeadExtend OFF
|
||
// Sensors : 2 sensors shared with Step 3 (FWD + BWD)
|
||
// BWD: Sen_HeadRetracted → advance trigger
|
||
// FWD: Sen_HeadAtWeldPos → conflict check (should be FALSE)
|
||
// Advance : Sen_HeadRetracted = TRUE AND Sen_HeadAtWeldPos = FALSE
|
||
//══════════════════════════════════════════════════════════════════
|
||
9:
|
||
Act_Clamp := TRUE;
|
||
Act_HeadExtend := FALSE;
|
||
Act_HeadRetract := TRUE;
|
||
_stepAdvReady := Sen_HeadRetracted AND NOT Sen_HeadAtWeldPos;
|
||
|
||
//══════════════════════════════════════════════════════════════════
|
||
// STEP 10 — UNCLAMP / PART EJECT
|
||
// Purpose : Release clamp and eject finished part
|
||
// Actuators: Act_Clamp OFF, Act_Unclamp ON, Act_PartEject ON
|
||
// Sensors : 1 sensor — Sen_UnclampConf (clamp fully open / part clear)
|
||
// Advance : Sen_UnclampConf = TRUE → COMPLETE
|
||
//══════════════════════════════════════════════════════════════════
|
||
10:
|
||
Act_Clamp := FALSE; // Release clamp
|
||
Act_Unclamp := TRUE; // Drive unclamp solenoid
|
||
Act_PartEject := TRUE; // Fire ejector cylinder
|
||
_stepAdvReady := Sen_UnclampConf;
|
||
|
||
END_CASE;
|
||
|
||
END_IF; // RUNNING or STOPPING_CAT1
|
||
|
||
(*═══════════════════════════════════════════════════════════════════════════
|
||
░░ S E C T I O N 6 — O U T P U T S A F E - S T A T E O V E R R I D E ░░
|
||
These rules override the step logic above for safety states
|
||
═══════════════════════════════════════════════════════════════════════════*)
|
||
|
||
// ── FAULTED (CAT0 or hard safety fault): ALL outputs immediately de-energised
|
||
IF _state = STATE_FAULTED THEN
|
||
Act_Clamp := FALSE;
|
||
Act_HeadExtend := FALSE;
|
||
Act_HeadRetract := FALSE;
|
||
Act_GasValve := FALSE;
|
||
Act_WeldEnable := FALSE;
|
||
Act_Unclamp := FALSE;
|
||
Act_PartEject := FALSE;
|
||
END_IF;
|
||
|
||
// ── IDLE / COMPLETE: weld-related outputs OFF; clamp may stay per design
|
||
IF _state = STATE_IDLE OR _state = STATE_COMPLETE THEN
|
||
Act_WeldEnable := FALSE;
|
||
Act_GasValve := FALSE;
|
||
Act_HeadExtend := FALSE;
|
||
Act_HeadRetract := FALSE;
|
||
Act_Unclamp := FALSE;
|
||
Act_PartEject := FALSE;
|
||
// NOTE: Act_Clamp intentionally left as-is here.
|
||
// Add Act_Clamp := FALSE if open-on-idle is required.
|
||
END_IF;
|
||
|
||
(*═══════════════════════════════════════════════════════════════════════════
|
||
░░ S E C T I O N 7 — S T A T U S O U T P U T S ░░
|
||
═══════════════════════════════════════════════════════════════════════════*)
|
||
ActiveStep := _activeStep;
|
||
SeqState := _state;
|
||
StepAdvanceReady := _stepAdvReady;
|
||
IncrWaiting := Mode_Incr AND _stepAdvReady AND NOT _incrRequest
|
||
AND (_state = STATE_RUNNING);
|
||
|
||
Seq_Idle := (_state = STATE_IDLE);
|
||
Seq_Running := (_state = STATE_RUNNING);
|
||
Seq_Paused := (_state = STATE_PAUSED);
|
||
Seq_Stopping := (_state = STATE_STOPPING_CAT1);
|
||
Seq_Stopped := (_state = STATE_STOPPED);
|
||
Seq_Faulted := (_state = STATE_FAULTED);
|
||
Seq_Complete := (_state = STATE_COMPLETE);
|
||
|
||
END_FUNCTION_BLOCK
|
||
|
||
|
||
(*═══════════════════════════════════════════════════════════════════════════════
|
||
USAGE CALL EXAMPLE — FC_WeldSeq_Call (or OB_CyclicInterrupt)
|
||
|
||
// In TIA Portal create an instance DB: DB_WeldSeq : FB_WeldSequencer
|
||
|
||
"DB_WeldSeq"(
|
||
Mode_Auto := %I2.0,
|
||
Mode_Incr := %I2.1,
|
||
Cmd_Start := %I1.4,
|
||
Cmd_Pause := %I1.5,
|
||
Cmd_Stop := %I1.6,
|
||
Cmd_EStop := %I1.2,
|
||
Cmd_Reset := %I1.3,
|
||
Cmd_Incr := %I1.7,
|
||
Cmd_SkipStep := %I2.2,
|
||
StopCategory := %MW10, // 0, 1 or 2 — set by HMI
|
||
Safety_DoorClosed := %I1.1,
|
||
Safety_EStopOK := %I1.0,
|
||
Sen_HomeFwd := %I0.0,
|
||
Sen_HomeBwd := %I0.1,
|
||
Sen_ClampClosed := %I0.2,
|
||
Sen_HeadAtWeldPos := %I0.3,
|
||
Sen_HeadRetracted := %I0.4,
|
||
Sen_ArcDetect := %I0.5,
|
||
Sen_ArcOff := %I0.6,
|
||
Sen_UnclampConf := %I0.7,
|
||
Act_Clamp => %Q0.0,
|
||
Act_HeadExtend => %Q0.1,
|
||
Act_HeadRetract => %Q0.2,
|
||
Act_GasValve => %Q0.3,
|
||
Act_WeldEnable => %Q0.4,
|
||
Act_Unclamp => %Q0.5,
|
||
Act_PartEject => %Q0.6,
|
||
Seq_Running => %Q1.0,
|
||
Seq_Paused => %Q1.1,
|
||
Seq_Faulted => %Q1.2,
|
||
Seq_Complete => %Q1.3,
|
||
ActiveStep => %MW20,
|
||
SeqState => %MW22,
|
||
FaultCode => %MW24,
|
||
StepAdvanceReady => %M5.0,
|
||
IncrWaiting => %M5.1,
|
||
CycleCount => %MD30
|
||
);
|
||
═══════════════════════════════════════════════════════════════════════════════*)
|