' tool change for VMC100 with 10 tool carousel
  
  ' -----------------------------------------
  ' output1 = override Z limit
  ' output2 = spindle air valve
  ' input2 = toolchanger clamped
  ' input3 = toolchanger some tool position
  ' input4 = toolchanger tool 1 position
  ' -----------------------------------------
  
  ' Variables
  ' -----------------------------------------
  ' wanted tool from Mach3
  tool = GetSelectedTool()
  ' current tool (0 if not known)
  CurrentTool = GetCurrentTool()
  ' position for tool change (+90.0mm)
  Zposition = 90
  ' spindle gear turns for one tool position change (in spindle full rev)
  ToolRevDistance = 2
  ' current spindle A axis position (in spindle full rev)
  ToolRevAngleNow = 0
  ' calculated movement of carousel (in tool positions! NOT revs)
  ToolRevRequired = 0
  ' single verify z axis number
  VerifyZaxis = 2
  VerifyAaxis = 3

  ' -----------------------------------------
  ' Check proper tool number
  
  If tool < 1 Or tool > 10 Then
    Message "ATC ERROR! New tool number not within 1-10!"
    End
  End If  
  If CurrentTool < 0 Or tool > 10 Then
    Message "ATC ERROR! Current tool number not within 0-10!"
    End
  End If    

  ' -----------------------------------------
  ' Check that spindle is stopped
  
  DoSpinStop() 
    
  ' -----------------------------------------
  ' Tool changer must be properly clamped
  
  If Not IsActive(INPUT2) Then
     Message "ATC ERROR! Toolchanger not initially clamped!"
     End
  End If
  
  ' -----------------------------------------
  ' Exit if correct tool already selected
  
  If tool = CurrentTool Then
    Message "ATC: Tool " & tool & " is already current tool."
    Exit Sub
  End If
  
  
  ' -----------------------------------------
  ' Home Z and A so position is definitely correct
  
  Message "ATC: Homing Z and A"
  ' Home A and Z 
  RefZ = 4
  RefA = 8
  RefCombination(RefZ + RefA)
  While IsMoving
     Sleep(100)
  Wend
  ' Home A a second time as sometimes first one doesn't work!!
  Message "ATC: Homing A again"
  RefCombination(RefA)
  While IsMoving
     Sleep(100)
  Wend
  Sleep(100)
  
  ' -----------------------------------------
  ' Proper rotary alignment for carousel gear
  
  Message "ATC: Setting A rotary alignment"
  ToolRevAngleNow = -0.025
  Code "G53 G01 A" & ToolRevAngleNow & " F100"
  While IsMoving
    Sleep(100)
  Wend 
  Sleep(100)

  
  ' -----------------------------------------
  ' override Z limit and run carousel up
  
  Message "ATC: Running to tool change position Z" & Zposition
  ' override Z limit to run carousel up
  ActivateSignal(OUTPUT1)
  Sleep(100)
  ' run Z to change position
  Code "G53 G01 Z" & Zposition & " F300"
  While IsMoving
     Sleep(100)
  Wend
  Sleep(100)

  ' -----------------------------------------
  ' run carousel to tool 1 (if no known tool position at start)
  
  If CurrentTool = 0 Then
    Message "ATC: Running carousel to tool 1"  
    While Not IsActive(INPUT4)
      ToolRevAngleNow = ToolRevAngleNow + ToolRevDistance
      Code "G53 G01 A" & ToolRevAngleNow & " F100"
      While IsMoving
        Sleep(100)
      Wend 
      Sleep(100)
      If IsActive(INPUT3) Then
    	message "ATC ERROR! Tool carousel not at any tool position!"
    	SetCurrentTool(0)
    	End
      End If
    Wend
    CurrentTool = 1
  End If
  
  ' -----------------------------------------
  ' run carousel to wanted tool (if not current tool)
  
  If Not CurrentTool = tool Then
    Message "ATC: Running carousel to tool " & tool
    ' movement required (in tool places! NOT REV!)
    ToolRevRequired = (CurrentTool - tool) 
    ' optimize movement
    If ToolRevRequired > 5 Then
      ToolRevRequired = ToolRevRequired - 10
    End If
    If ToolRevRequired < -5 Then
      ToolRevRequired = ToolRevRequired + 10
    End If
    ' move to new tool 
    ToolRevAngleNow = ToolRevAngleNow + ToolRevRequired * ToolRevDistance
    Code "G53 G01 A" & ToolRevAngleNow & " F100"
    While IsMoving
      Sleep(100)
    Wend 
    Sleep(100)
    If IsActive(INPUT3) Then
      message "ATC ERROR! Tool carousel not at any tool position!"
      SetCurrentTool(0)
      End
    End If  
  End If

  ' -----------------------------------------
  ' Air blast

  Message "ATC: Cleaning spindle with air"
  ActivateSignal(OUTPUT2)
  Sleep(1000)
  DeActivateSignal(OUTPUT2)
  
  ' -----------------------------------------
  ' Run Z back down and enable Z limit

  Message "ATC: Running Z back down"
  ' run Z back down
  Code "G53 G01 Z0 F300"
  While IsMoving
    Sleep(100)
  Wend 
  Sleep(100)
  ' Reactivate Z limit 
  DeactivateSignal(OUTPUT1)

  ' -----------------------------------------
  ' Tool changer must be properly clamped

  If Not IsActive(INPUT2) Then
     Message "ATC ERROR! Toolchanger not clamped!"
     SetCurrentTool(0)
     End
  End If
    
  ' -----------------------------------------
  ' tool is changed
  
  Message "ATC: Tool " & tool & " changed successfully!"
  SetCurrentTool( tool )

  ' end