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• Signal state change to 50 (Fast close init)
• Load fast close speeds
• If neither at position P1 (positive closed) nor at position P2 (negative closed), then
  • Move (MA) to the positive closed position (P1)
  • If error checking is enabled (Ec=1), check drift at previous, assumed negative closed position (call X8)
  • Hold until movement complete
  • Set Df=1 to indicate that slits are in positive closed position
  • Copy current encoder count to Cs for future drift checks
• EndIf
• Signal state change to 51 (Fast close complete)
• Goto mode select

Subroutines

Drift Check at Positive Closed Position (X8)

• If Df==1 (position is positive closed position), then
  • Let Dr=N1-Cs, such that Dr is positive if the motor is slipping (missing steps while travelling in the positive direction)
  • If Dr >= Dl (drift limit), then
    • Set Ld=1, indicating a drift limit violation in the negative direction
  • EndIf
• EndIf
• Return

Drift Check at Negative Closed Position (X9)

• If Df==-1 (position is negative closed position), then
  • Let Dr=Cs-N2, such that Dr is positive if the motor is slipping (missing steps while traveling in the negative direction)
  • If Df >= Dl (drift limit), then
    • Set Ud=1, indicating a drift limit violation in the negative direction
  • EndIf
• EndIf
• Return

Mode/State Tables

Se - Mode Select

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