(*═══════════════════════════════════════════════════════════════════════════════
  DEMO_WeldCellIntegration.scl
  ─────────────────────────────────────────────────────────────────────────────
  Demonstrates FB_CylinderMonitor instances for all 4 sensor configurations
  wired into the FB_WeldSequencer from the welding cell demo.

  CYLINDERS IN THIS DEMO:
  ┌──────┬───────────────────────┬──────────────┬────────────────────────────┐
  │ Inst │ Cylinder              │ SensorConfig  │ Notes                      │
  ├──────┼───────────────────────┼──────────────┼────────────────────────────┤
  │ DB1  │ Clamp Cylinder        │ ONE_FWD (1)  │ Only clamp-closed sensor   │
  │ DB2  │ Weld Head             │ TWO (3)      │ Extended + retracted sensor │
  │ DB3  │ Part Ejector          │ ONE_BWD (2)  │ Only retracted (home) sensor│
  │ DB4  │ Gas Purge Valve       │ NONE (0)     │ No position sensor, timer  │
  └──────┴───────────────────────┴──────────────┴────────────────────────────┘

  RESPONSE CONFIGURATION:
    Timeout faults  → PAUSE machine  (operator can clear & resume)
    Conflict faults → STOP  machine  (requires Reset before restart)
    Lost position   → STOP  machine  (requires Reset before restart)

  CALL ORDER in OB (important — monitors must execute BEFORE sequencer):
    1. FB_CylinderMonitor instances (DB1..DB4)
    2. FB_CylFaultCollector         (DB_CylFaults)
    3. FB_WeldSequencer             (DB_WeldSeq)
═══════════════════════════════════════════════════════════════════════════════*)

//─────────────────────────────────────────────────────────────────────────────
// INSTANCE DB DECLARATIONS (create these in TIA Portal project tree)
//
//   DB_CylClamp    : FB_CylinderMonitor
//   DB_CylHead     : FB_CylinderMonitor
//   DB_CylEject    : FB_CylinderMonitor
//   DB_CylGas      : FB_CylinderMonitor
//   DB_CylFaults   : FB_CylFaultCollector
//   DB_WeldSeq     : FB_WeldSequencer
//─────────────────────────────────────────────────────────────────────────────

//═════════════════════════════════════════════════════════════════════════════
//  CYLINDER 1 — CLAMP   (ONE_FWD: only clamp-closed sensor at FWD end)
//  ─────────────────────────────────────────────────────────────────────────
//  Physical setup:
//    Proximity sensor mounted at closed (extended) jaw position ONLY.
//    No sensor at open position — we assume open if no clamp command active.
//
//  Error logic:
//    Cmd_Fwd (clamp) active → Sen_Fwd (clamp closed) not confirmed in 2 s
//      → FaultCode 1 (FWD timeout) → machine PAUSE
//    Sen_Fwd unexpectedly active with no command? → Not detected (ONE_FWD limit)
//
//  Advance in sequencer:
//    Step 2 advance condition: DB_CylClamp.AtFwd
//═════════════════════════════════════════════════════════════════════════════
"DB_CylClamp"(
    CylName      := 'Clamp Cylinder',
    SensorConfig := 1,                  // ONE_FWD
    T_Timeout    := T#2S,               // 2 second fault timeout
    Cmd_Fwd      := "DB_WeldSeq".Act_Clamp,    // Sequencer output drives FWD
    Cmd_Bwd      := NOT "DB_WeldSeq".Act_Clamp AND NOT "DB_WeldSeq".Seq_Faulted,
                                        // Bwd inferred: not clamped & not faulted
    Cmd_Reset    := "PB_Reset",
    Sen_Fwd      := %I0.2,             // Sen_ClampClosed hardware input
    Sen_Bwd      := FALSE,             // No sensor at open position
    Enable       := "DB_WeldSeq".Seq_Running OR "DB_WeldSeq".Seq_Paused
);

//═════════════════════════════════════════════════════════════════════════════
//  CYLINDER 2 — WELD HEAD   (TWO sensors: extended + retracted)
//  ─────────────────────────────────────────────────────────────────────────
//  Physical setup:
//    Sensor at fully extended (weld position) = Sen_Fwd  → %I0.3
//    Sensor at fully retracted (safe position) = Sen_Bwd → %I0.4
//
//  Error logic:
//    Extend cmd → Sen_Fwd not confirmed in 3 s → FaultCode 1 → PAUSE
//    Retract cmd → Sen_Bwd not confirmed in 3 s → FaultCode 2 → PAUSE
//    Both sensors TRUE simultaneously → FaultCode 3 → STOP
//    Sensors both drop with no command active → FaultCode 4 (lost) → STOP
//
//  Advance in sequencer:
//    Step 3 advance: DB_CylHead.AtFwd
//    Step 9 advance: DB_CylHead.AtBwd
//
//  NOTE: Extend and Retract are separate solenoid outputs (bistable valve)
//    CylCmd_FwdSafe → Act_HeadExtend solenoid
//    CylCmd_BwdSafe → Act_HeadRetract solenoid
//═════════════════════════════════════════════════════════════════════════════
"DB_CylHead"(
    CylName      := 'Weld Head',
    SensorConfig := 3,                  // TWO sensors
    T_Timeout    := T#3S,               // 3 seconds (head travel takes longer)
    Cmd_Fwd      := "DB_WeldSeq".Act_HeadExtend,
    Cmd_Bwd      := "DB_WeldSeq".Act_HeadRetract,
    Cmd_Reset    := "PB_Reset",
    Sen_Fwd      := %I0.3,             // Sen_HeadAtWeldPos
    Sen_Bwd      := %I0.4,             // Sen_HeadRetracted
    Enable       := "DB_WeldSeq".Seq_Running OR "DB_WeldSeq".Seq_Paused
                    OR "DB_WeldSeq".Seq_Stopping
);

// ── Wire safe outputs back to physical DQs ───────────────────────────────
%Q0.1 := "DB_CylHead".CylCmd_FwdSafe;  // Act_HeadExtend (gated)
%Q0.2 := "DB_CylHead".CylCmd_BwdSafe;  // Act_HeadRetract (gated)

//═════════════════════════════════════════════════════════════════════════════
//  CYLINDER 3 — PART EJECTOR   (ONE_BWD: only home/retracted sensor)
//  ─────────────────────────────────────────────────────────────────────────
//  Physical setup:
//    The ejector fires forward (extends) to push the part out.
//    Sensor only at retracted (home) end — confirms ejector is clear/home.
//    No sensor at extended (ejected) position.
//
//  Error logic:
//    Retract cmd (home return) → Sen_Bwd not confirmed in 1.5 s
//      → FaultCode 2 (BWD timeout) → PAUSE
//    Eject (FWD) cmd: no FWD sensor, so no timeout — just fires blind.
//      After timer completes in sequencer, retract command issued.
//
//  Advance in sequencer:
//    Step 10 advance uses Sen_UnclampConf (%I0.7) which is separate.
//    After cycle complete, this FB confirms ejector is home before next cycle.
//═════════════════════════════════════════════════════════════════════════════
"DB_CylEject"(
    CylName      := 'Part Ejector',
    SensorConfig := 2,                  // ONE_BWD
    T_Timeout    := T#1500MS,
    Cmd_Fwd      := "DB_WeldSeq".Act_PartEject,
    Cmd_Bwd      := NOT "DB_WeldSeq".Act_PartEject
                    AND "DB_WeldSeq".Seq_Complete,
    Cmd_Reset    := "PB_Reset",
    Sen_Fwd      := FALSE,             // No sensor at ejected position
    Sen_Bwd      := %I0.7,            // Ejector home sensor (shared / Sen_UnclampConf area)
    Enable       := TRUE               // Always enabled
);

//═════════════════════════════════════════════════════════════════════════════
//  CYLINDER 4 — GAS PURGE VALVE   (NONE: no position sensors)
//  ─────────────────────────────────────────────────────────────────────────
//  Physical setup:
//    Simple solenoid valve — open or closed.
//    No position feedback — valve assumed open when energised.
//    No fault can be generated from position sensors (none exist).
//
//  Error logic:
//    NONE: the FB passes the command through, reports AT_FWD when commanded
//    On/Off confirmed only by timer in the sequencer (Steps 4, 6, 8).
//
//  NOTE: A pressure switch or flow sensor could be added here in future.
//        Connect it to Sen_Fwd and change SensorConfig to ONE_FWD.
//═════════════════════════════════════════════════════════════════════════════
"DB_CylGas"(
    CylName      := 'Gas Purge Valve',
    SensorConfig := 0,                  // NONE
    T_Timeout    := T#500MS,           // Not used with NONE config (no timers start)
    Cmd_Fwd      := "DB_WeldSeq".Act_GasValve,
    Cmd_Bwd      := FALSE,             // Single-acting valve — spring return
    Cmd_Reset    := "PB_Reset",
    Sen_Fwd      := FALSE,
    Sen_Bwd      := FALSE,
    Enable       := TRUE
);

//═════════════════════════════════════════════════════════════════════════════
//  FAULT COLLECTOR — Aggregates all 4 cylinder faults
//  Outputs feed directly into the sequencer Cmd_Pause / Cmd_Stop inputs
//═════════════════════════════════════════════════════════════════════════════
"DB_CylFaults"(
    //── Fault bits ───────────────────────────────────────────────────────────
    Cyl1_Fault         := "DB_CylClamp".Fault_Active,
    Cyl2_Fault         := "DB_CylHead".Fault_Active,
    Cyl3_Fault         := "DB_CylEject".Fault_Active,
    Cyl4_Fault         := "DB_CylGas".Fault_Active,
    Cyl5_Fault         := FALSE,
    Cyl6_Fault         := FALSE,
    Cyl7_Fault         := FALSE,
    Cyl8_Fault         := FALSE,

    //── Fault codes ───────────────────────────────────────────────────────────
    Cyl1_FaultCode     := "DB_CylClamp".FaultCode,
    Cyl2_FaultCode     := "DB_CylHead".FaultCode,
    Cyl3_FaultCode     := "DB_CylEject".FaultCode,
    Cyl4_FaultCode     := "DB_CylGas".FaultCode,
    Cyl5_FaultCode     := 0,
    Cyl6_FaultCode     := 0,
    Cyl7_FaultCode     := 0,
    Cyl8_FaultCode     := 0,

    //── HMI fault texts ───────────────────────────────────────────────────────
    Cyl1_FaultText     := "DB_CylClamp".HMI_FaultText,
    Cyl2_FaultText     := "DB_CylHead".HMI_FaultText,
    Cyl3_FaultText     := "DB_CylEject".HMI_FaultText,
    Cyl4_FaultText     := "DB_CylGas".HMI_FaultText,

    //── Machine response policy ───────────────────────────────────────────────
    // Timeout  → PAUSE (1): operator can check & reset, then resume
    // Conflict → STOP  (2): two sensors TRUE = hardware fault, needs investigation
    // Lost pos → STOP  (2): cylinder moved undetected = mechanical issue
    Response_Timeout   := 1,
    Response_Conflict  := 2,
    Response_Lost      := 2
);

//═════════════════════════════════════════════════════════════════════════════
//  WELDING SEQUENCER — Wired with cylinder feedback and fault injection
//═════════════════════════════════════════════════════════════════════════════
"DB_WeldSeq"(
    //── Mode & commands ─────────────────────────────────────────────────────
    Mode_Auto           := %I2.0,
    Mode_Incr           := %I2.1,
    Cmd_Start           := %I1.4,
    Cmd_Reset           := "PB_Reset",

    // ── PAUSE: operator button OR cylinder fault requesting pause ──────────
    Cmd_Pause           := %I1.5
                           OR "DB_CylFaults".Cmd_MachinePause,

    // ── STOP: operator button OR cylinder fault requesting stop ───────────
    Cmd_Stop            := %I1.6
                           OR "DB_CylFaults".Cmd_MachineStop,

    Cmd_EStop           := %I1.2,
    Cmd_Incr            := %I1.7,
    Cmd_SkipStep        := %I2.2,
    StopCategory        := %MW10,

    //── Safety inputs ────────────────────────────────────────────────────────
    Safety_DoorClosed   := %I1.1,
    Safety_EStopOK      := %I1.0,

    //── Sensors — using GATED outputs from cylinder monitors where possible ──
    //    Sequencer only sees "AtFwd/AtBwd" from healthy, confirmed cylinders.
    //    If cylinder monitor is faulted, AtFwd/AtBwd → FALSE → step never
    //    advances → watchdog trips → sequencer also faults. Belt & braces.

    Sen_HomeFwd         := %I0.0,                        // No cylinder monitor (robot)
    Sen_HomeBwd         := %I0.1,

    // Step 2 clamp — uses cylinder monitor's AtFwd (confirmed clamp closed)
    Sen_ClampClosed     := "DB_CylClamp".AtFwd,          // ← From monitor, not raw DI

    // Steps 3 & 9 — weld head FWD/BWD (from monitor)
    Sen_HeadAtWeldPos   := "DB_CylHead".AtFwd,           // ← Confirmed extended
    Sen_HeadRetracted   := "DB_CylHead".AtBwd,           // ← Confirmed retracted

    Sen_ArcDetect       := %I0.5,
    Sen_ArcOff          := %I0.6,

    // Step 10 unclamp (ejector home or unclamp sensor)
    Sen_UnclampConf     := "DB_CylEject".AtBwd,          // ← Ejector home confirmed

    //── Actuator outputs ─────────────────────────────────────────────────────
    // NOTE: Act_HeadExtend and Act_HeadRetract go through the head cylinder
    //       monitor's gated outputs (see %Q assignments above).
    //       Act_Clamp goes direct here — the monitor checks it on its own scan.
    Act_Clamp           => %Q0.0,
    Act_HeadExtend      => "DB_CylHead_CmdFwd_Raw",      // Internal tag; monitor gates it to %Q0.1
    Act_HeadRetract     => "DB_CylHead_CmdBwd_Raw",      // Internal tag; monitor gates it to %Q0.2
    Act_GasValve        => %Q0.3,
    Act_WeldEnable      => %Q0.4,
    Act_Unclamp         => %Q0.5,
    Act_PartEject       => %Q0.6,

    //── Status outputs ───────────────────────────────────────────────────────
    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
);

//═════════════════════════════════════════════════════════════════════════════
//  HMI WIRING SUMMARY
//  Wire these tags to your WinCC/Comfort panel for operator guidance:
//
//  TAG                                  SOURCE                  HMI ELEMENT
//  ─────────────────────────────────────────────────────────────────────────
//  DB_WeldSeq.ActiveStep     → %MW20   Step indicator (1-10)
//  DB_WeldSeq.SeqState       → %MW22   State text list
//  DB_WeldSeq.FaultCode      → %MW24   Sequencer alarm
//  DB_CylFaults.FirstFaultText          First fault banner text
//  DB_CylFaults.CylFaultWord            Cylinder fault bitmask (overview)
//  DB_CylFaults.ActiveFaultCount        Number of active faults
//  DB_CylClamp.CylState                 Clamp position indicator
//  DB_CylClamp.HMI_StatusText           Clamp status string
//  DB_CylHead.CylState                  Head position indicator
//  DB_CylHead.HMI_StatusText            Head status string
//  DB_CylEject.CylState                 Ejector status
//  DB_CylHead.Moving                    Moving animation trigger
//  DB_CylFaults.Cmd_Warning    → %Q1.4  Amber warning lamp
//  DB_WeldSeq.Seq_Faulted      → %Q1.2  Red fault lamp
//  DB_WeldSeq.IncrWaiting      → %M5.1  "Press INCR" flashing indicator
//═════════════════════════════════════════════════════════════════════════════