Plunger Component Documentation

Plunger

Path: src/Plunger.cpp

Revision History: Initial documentation

The Plunger component controls a motor-driven plunger mechanism through a Variable Frequency Drive (VFD). It manages various states including homing, plunging, filling operations, and post-flow sequences while allowing both manual and automatic operation modes.

Requirements

Hardware

• VFD-controlled motor connected to plunger mechanism
• Joystick peripheral for manual control
• Modbus-485 communication interface

Configuration

• Multiple configurable speed settings
• Operation timing parameters
• Auto mode hold durations

Features

• Multiple operation modes:
  • Manual control via joystick
  • Auto mode via joystick hold
  • Replay of recorded plunge sequences
  • Filling sequence with configurable parameters
  • Post-flow sequence for pressure maintenance
• State machine design with comprehensive state transitions
• Jam detection and recovery
• Modbus control interface
• Configurable timings and speeds
• Recording and replaying of plunge operations

Dependencies

• Arduino Framework
• VFD Component
• Joystick Component
• Ticker Library
• ModbusTCP

Behavior

The Plunger component operates as a state machine with the following states:

TODOs

Performance

• Consider optimizing timer usage to reduce RAM footprint
• Evaluate performance impact of multiple state transitions during operation
• Implement configurable acceleration/deceleration profiles for smoother operation
• Assess VFD command frequency to prevent communication bottlenecks

Security

• Implement validation of Modbus command sources
• Add access control to prevent unauthorized command execution
• Consider adding confirmation requirements for critical operations
• Log and alert on suspicious command patterns

Compliance

• Ensure compliance with relevant machine safety standards
• Consider implementing additional safety interlocks
• Document safety requirements and certifications
• Follow applicable electrical code requirements for industrial equipment

Recommendations

• Monitor VFD current to detect potential mechanical issues before jam events
• Implement a maintenance log for plunger operations
• Consider adding physical position sensing for more precise control
• Develop UX guidelines for joystick operation to minimize user error
• Create a calibration routine for optimal performance with different materials

Example

The following example shows how to initialize and mount a Plunger component:

#ifdef PIN_PLUNGER_1_ENABLE
  vfd_1 = new VFD(
      this,              // owner
      PIN_PLUNGER_1_ENABLE,  // enablePin
      PIN_PLUNGER_1_FORWARD, // forwardPin
      PIN_PLUNGER_1_COM,     // communicationPin
      PIN_PLUNGER_1_ALARM,   // alarmPin
      PLUNGER_1_ID_VFD       // id
  );

  joystick_1 = new Joystick(
      this,               // owner
      PIN_PLUNGER_1_JOYSTICK_X,  // pinX
      PIN_PLUNGER_1_JOYSTICK_Y,  // pinY
      PLUNGER_1_ID_JOYSTICK      // id
  );

  if (vfd_1 && joystick_1)
  {
    plunger_1 = new Plunger(
        this,             // owner
        vfd_1,            // vfd
        joystick_1,       // joystick
        PLUNGER_1_ID      // id
    );

    // Configure plunger settings
    plunger_1->settings.speedRampHz = PLUNGER_1_SPEED_RAMP_HZ;
    plunger_1->settings.speedSlowHz = PLUNGER_1_SPEED_SLOW_HZ;
    plunger_1->settings.speedMaxHz = PLUNGER_1_SPEED_MAX_HZ;
    plunger_1->settings.autoModeHoldDurationMs = PLUNGER_1_AUTO_MODE_HOLD_DURATION_MS;
    plunger_1->settings.defaultMaxOperationDurationMs = PLUNGER_1_MAX_OPERATION_DURATION_MS;
    plunger_1->settings.enablePostFlow = PLUNGER_1_ENABLE_POST_FLOW;

    // Add to components list
    if (plunger_1) {
      components.push_back(vfd_1);
      components.push_back(joystick_1);
      components.push_back(plunger_1);

      Log.infoln(F("Plunger_1 initialized with VFD and Joystick"));
    }
    else {
      Log.errorln(F("Plunger_1 initialization failed."));
    }
  }
  else {
    Log.errorln(F("VFD_1 or Joystick_1 initialization failed, cannot create Plunger_1."));
  }
#endif

References