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• Signal state change to 70 (Homing init)
• Load homing/alignment speeds (CL V9)
• Execute home-to-index (HI) with option 3 (slew at VM in + direction, creep in - direction)
• Hold until movement complete
• Relative move (MR) by Mo to positive closed position
• Hold until movement complete
• Set C1 to P1 - tell the motor where it is
• Set C2 to N1 - tell the encoder where it is
• Set Cs to C2 - copy the encoder count to shadow register
• Set Df to 1 (positive closed position, known)
• Reset limit violation counters Ld and Ud to 0
• Signal state change to 79 (Homing complete)
• Goto mode select

Subroutines

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Blocking move to nearest closed position (

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LB X5)

This routine updates the open-loop position based on the encoder reading. The target position of any subsequent move will be better aligned.

• Declare local variables L1, L2
• Compute the new open-loop position: C2 * <encoder counts per rev> / <microsteps per rev> = (C2 * EL * 8) / (MS * 200)
  • L1=C2*EL*8
  • L2=MS*200
• Write the new open-loop position to C1. (C1=L1/L2)
• Set Df=98 (Realigned)
• Return

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 traveling in the positive direction)
  • If Dr >= Dl (drift limit), then
    • Ld=Ld+1, Increment Ld drift violation counter
  • EndIf
• EndIf
• Return

Drift Check at Negative Closed Position (X9)

closes the pulse picker to the positive closed position P1 if it is not already closed.

• If not already in the positive or negative closed position (Df<>1 AND Df<>-1)
  • Move to positive closed position (P1)
  • Hold until movement is complete

• • Copy current encoder count to Cs for future drift checks
  • Signal at positive closed position (Df=1)
• EndIf

Realign by computing new open-loop position (X7)

This routine updates the open-loop position based on the encoder reading. The target position of any subsequent move will be better aligned.

• Declare local variables L1, L2
• Compute the new open-loop position: C2 * <encoder counts per rev> / <microsteps per rev> = (C2 * EL * 8) / (MS * 200)
  • L1=C2*EL*8
  • L2=MS*200
• Write the new open-loop position to C1. (C1=L1/L2)
• Set Df=98 (Realigned)
• 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
    • Ud=Ud+1, Increment Ud drift violation counter
  • EndIf
• EndIf
• Return

Mode/State Tables

Se - Mode Select

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