Page Comparison

ECS or Local HMI send mode, position reference, velocity reference.

All motion control logic is located in Routine Control_position.

Sequence of operation

Wait for position command

Wait for mode

Routine Az_Mode sets mode based on ECS or Local commands.

Control_position is active only in Local PTP or Remote PTP, Jog, Offset.

Wait for command

ECS sends new ID and position ID or new position reference from ECS or Local.
Each change in ID or position reference are executed and replace any current operation.

Reset

Reset position logic when:

• Entering or leaving PTP mode

• Entering tracking mode

• PLC first scan

• Fault reset

Point to Point or Offset or Remote Jog move

Position reference

Assign Position Reference based on mode.

Check for valid Position Reference.

Check for valid move direction.

Check if Actual Position crossed Position Reference.

Position error

Calculate Position Error.

Check if Position Error is within tolerance.

Wait for motion command

• change in ECS command ID

• change in Position Reference

Stop move

Manual command, available only in PLC editor

New move

Initialize

Reset state controls and parameters.

Validate motion  parameters.

Calculate 

• Starting Speed (based on mode and Position Error).

• Accel, decel, distance & time 

• Direction of travel

Start move

Move in Progress = ON

End move

Wait for

• Position Error < stop lead distance

• Actual Position crossed Position Reference (Position Error changed sign)

• Safety stop

• Entering Tracking Mode

• Cancel move

Move in progress = OFF

While move in progress

Control speed

• Initial Speed Reference = Starting Speed

• While position error < near distance : Speed = near speed

• While position error < creep distance : Speed = creep speed

• While position error < final distance : Speed = final speed

Control acceleration

While position error > 3° (Ramp control)

• Accel = 100 RPM / sec (~0.1° / sec)

• Decel = 50 RPM / sec

• Jerk = 20  RPM / sec / sec (S-curve)

While position error < 3° (Quick response for stopping)

• Accel = 500 RPM / sec (~0.5° / sec)

• Decel = 500 RPM / sec

• Jerk = 500 RPM / sec / sec (no curve)

Tracking mode

Position Error smoothing

Selectable

First order low pass filter with tunable time constant.

Reduce response to encoder jitter

Speed reference

= Velocity + (Position error * proportional gain)

Tracking motion control

Speed output control

If Tracking or Move in progress

Send Position Speed Reference to Control_Speed

else Speed reference = 0

Control Loop

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