Page Comparison

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ECS can control motion in four operating modes

• Tracking - ECS sends Position Reference and Speed Reference

• Point to Point - ECS sends Position Reference and sometimes sends Speed Reference

• Jogging and Offset - modes are not used

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• EMCS / Azimuth / Control Speed
  Setup Control Loop :
  Position and Speed Reference
  Position Error control modes
  Tuning parameters
  Speed limits
  Response timesfor selected mode

• EMCS / Azimuth / Control Loop
  Calculate Speed Reference to Azimuth Drives for Position Control or Speed Control

EMCS PLC controls Enclosure Azimuth motion in two control modes

• Position Control
  Operate to maintain Actual Position = Position Reference

• Speed Control
  Operate to move Azimuth at Speed Reference

Enclosure Azimuth motion during observation

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PLC Routine: Control Speed

Set Position and Speed Reference
Calculate Position Error
Set Tuning parameters based on position error (Homing, Tracking, Fine Tracking
Set Speed limits based on operating mode
Position ControlSet response times for PI, signal filtering and output curve shaping
Calculate inflection point (change in direction) of Position Setpoint

PI (Proportional / Integral) closed loop control

Calculate PI output
Clamp maximum integral error
Clamp PI output
Add ECS speed reference
Clamp maximum speed output
Convert degrees / second to RPM