Page History

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• Wiki Markup
  *Se* \- Pulse Picker mode \[Se\]lect. Refer to Mode List for a complete list of Se modes.

• Sd - Status indicator register. Used for debugging. Refer to Status List for a complete list of statuses.

• Wiki Markup
  *Sw* \- \[Sw\]eep distance. Number of motor steps to equal 11.25 degrees of motion.

• Sr - Encoder sweep distance. Number of encoder steps to equal 11.25 degrees of motion.

• Wiki Markup
  *Dr* \- Encoder \[Dr\]ift, or the difference between the encoder count the predicted encoder position.

• P0 - Center (open) position, in motor steps.
• P1 - Positive closed position, in motor steps, nominally P0+Sw. (Repurposed from standard MCode program.)
• P2 - Negative closed position, in motor steps, nominally P0-Sw.
• N0 - Center (open) position, in encoder counts.
• N1 - Positive closed position, in encoder counts, nominally N0+Sr.
• N2 - Negative closed position, in encoder counts, nominally N0-Sr.
• Ec - Error checking flag. (0=OFF, 1=ON)
• Ns - Pulse Picker MCode version. (Repurposed from standard MCode program.)
• Hb - Heartbeat counter, incremented approx. every 100ms.
• Cs - Encoder counter shadow register (=C2+)
• Ud - Drift violation, motor drifting in + direction (0= NO ERROR, 1=VIOLATION)
• Ld - Drift violation, motor drifting in - direction (0=NO ERROR, 1=VIOLATION)
• Df - Motor position flag (see interpretation below)

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• If Se<>0, we are likely experiencing a hard reset. In that case:
  • Signal state change to 80 (Hard Reset Initialization)
  • Set EL (Encoder lines) to 4096, giving 4096 lines * 4 steps/line = 16384 steps/rev
  • Set MS (Microsteps) to 8, giving 8 uSteps/step * 200 step/rev = 1600 uSteps/rev
  • Set EE (Encoder enabled) to 0, forcing open-loop step mode. Closed-loop mode is too slow because of a 1kHz loop rate.
  • Set S3 (I/O 3 settings) to 16,0,1. This is used for encoder power - sourcing output, active low.
  • Set O3 (Output 3) to 1, turning the encoder on.
  • Set S4 (I/O 4 settings) to 16,0,0. This is used for fan power - sinking power, active low.
  • Set O4 (Output 4) to 1, turning the fan on.
  • Set S13 (I/O 13 settings) to 60,0,0. This is used for input signaling, and makes it available to the input capture trip (interrupt)
  • Set FC (Filter Capture) to 9. This sets a debounce filter on input 13 with a 12.9usec delay time.
  • Set HT (Hold Time) to 5, setting the hold current delay time to 5ms.
  • Set RC (Run Current) to 100, making 100% of current available for movement.
  • Set HC (Holding Current) to 5.
  • Set NE (Numeric Enable) to 0, to prevent errant communications as being interpreted as movement commands.
  • Set Pu (Power-Up Flag) to 0 to prevent IOC from locking itself.
  • Set Sw (Sweep Distance) to 50 steps.
  • Set Sr (Encoder Sweep Distance) to 512 counts.
  • Reset Dr (Drift) to 0.
  • Reset P0 (Open position) to 0.
  • Reset P1 (Positive closed position) to P0+Sw = 512.
  • Reset P2 (Negative closed position) to P0-Sw = -512.
  • Reset N0 (Open encoder position) to 0.
  • Reset N1 (Positive closed encoder position) to N0+Sr.
  • Reset N2 (Negative closed encoder position) to N0-Sr.
  • Pre-load shadow registers: Po=P, register Cs=C2
  • Set Ec=1 to turn error checking on.
  • Reset drift violation flags Ud and Ld to 0.
  • Reset Df to 99 (current slit position is unknown)
• For both hard and soft resets, we do the following
  • Signal state change to 81 (Soft Reset Initialization)
  • Disable any trips (TE=0)
  • Hold for 100ms to let things stabilize.
  • Set Se (Mode Select) to 0
  • Goto Mode Select Loop

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