Straight-line folder gluer, 6.2 m

Install first: TIA Portal V18+, S7-1200 firmware 4.4+

(* Straight-line folder gluer: Siemens S7-1200, SCL (Structured Text).
   Inputs: I0.0/I0.1 encoder (HSC1, 1000 ppr), I0.2 Start, I0.3 Stop (NC), I0.4 Safety OK,
   I0.5 blank fed, I0.6 glue trigger, I0.7 count, I1.0 jam, I1.1/I1.2 VFD faults,
   I1.3 blower breaker on, I1.4 glue low, I1.5 air OK.
   Outputs: Q0.0 feeder run, Q0.1 belts run, Q0.2 blower, Q0.3/Q0.4 glue guns,
   Q0.5 kicker, Q0.6 glue pump, Q0.7/Q1.0/Q1.1 stack light. *)

// --- Settings (change on the HMI) ---
// GlueStartMm / GlueLengthMm: where each glue line starts after the trigger eye, and how long it is
// MmPerPulse: belt travel per encoder pulse (roller circumference 314 mm / 1000 ppr)

CASE #State OF
  0: // IDLE
    "Q_FeederRun" := FALSE; "Q_BeltsRun" := FALSE; "Q_Blower" := FALSE; "Q_GluePump" := FALSE;
    IF "I_SafetyOK" AND "I_AirOK" AND "I_BlowerOn" AND NOT #Fault AND "I_Start" THEN
      #T_Start(IN := FALSE); #State := 1;
    END_IF;

  1: // STARTING: blower and belts first, feeder after 2 s with the horn
    "Q_Blower" := TRUE; "Q_BeltsRun" := TRUE; "Q_GluePump" := TRUE;
    #T_Start(IN := TRUE, PT := T#2S);
    IF #T_Start.Q THEN "Q_FeederRun" := TRUE; #State := 2; END_IF;

  2: // RUNNING
    // Glue: arm on the trigger edge, fire between start and end distance
    #R_Trig(CLK := "I_GlueEye");
    IF #R_Trig.Q THEN #TriggerCount := "HSC1_Value"; END_IF;
    #Travel := DINT_TO_REAL("HSC1_Value" - #TriggerCount) * #MmPerPulse;
    "Q_Gun1" := #Armed AND #Travel >= #GlueStartMm AND #Travel < #GlueStartMm + #GlueLengthMm;
    "Q_Gun2" := "Q_Gun1" AND #TwoLines;
    IF #Travel > #GlueStartMm + #GlueLengthMm + 50.0 THEN #Armed := FALSE; ELSIF #R_Trig.Q THEN #Armed := TRUE; END_IF;

    // Count and batch-mark every BatchSize cartons
    #CountTrig(CLK := "I_CountEye");
    IF #CountTrig.Q THEN
      #Count := #Count + 1; #BatchCount := #BatchCount + 1;
      IF #BatchCount >= #BatchSize THEN #BatchCount := 0; #T_Kick(IN := TRUE, PT := T#150MS); END_IF;
    END_IF;
    #T_Kick(IN := #T_Kick.IN AND NOT #T_Kick.Q); "Q_Kicker" := #T_Kick.IN;

    // Jam: the jam flag must clear within 1.5 s
    #T_Jam(IN := "I_Jam", PT := T#1500MS);
    IF #T_Jam.Q THEN #FaultCode := 1; #Fault := TRUE; END_IF;
    IF "I_Stop" = FALSE THEN #State := 3; END_IF; // NC stop button opened

  3: // STOPPING: feeder off, let the last cartons out
    "Q_FeederRun" := FALSE; "Q_Gun1" := FALSE; "Q_Gun2" := FALSE;
    #T_Run(IN := TRUE, PT := T#4S);
    IF #T_Run.Q THEN #T_Run(IN := FALSE); #State := 0; END_IF;

  9: // FAULT: everything off until reset from the HMI
    "Q_FeederRun" := FALSE; "Q_BeltsRun" := FALSE; "Q_Blower" := FALSE;
    "Q_Gun1" := FALSE; "Q_Gun2" := FALSE; "Q_GluePump" := FALSE;
    IF "HMI_Reset" AND "I_SafetyOK" AND NOT "I_Jam" THEN #Fault := FALSE; #FaultCode := 0; #State := 0; END_IF;
END_CASE;

// Faults from anywhere stop the machine
IF NOT "I_SafetyOK" THEN #FaultCode := 2; #Fault := TRUE; END_IF;
IF "I_VFD1Fault" OR "I_VFD2Fault" THEN #FaultCode := 3; #Fault := TRUE; END_IF;
IF NOT "I_AirOK" THEN #FaultCode := 4; #Fault := TRUE; END_IF;
IF #Fault THEN #State := 9; END_IF;

// Stack light: green running, amber glue low or stopping, red fault (flashing)
"Q_LampGreen" := #State = 2;
"Q_LampAmber" := "I_GlueLow" OR #State = 3;
"Q_LampRed" := #Fault AND "Clock_1Hz";