SimpleMotion motion control strategies

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SimpleMotion V2 allows building single and multi-axis motion control applications in three different strategies. The table below summarizes the options.

Strategy Implementation Features Cons Need real-time host Synchronized multi-axis motion
Parameter communication

Send setpoint commands to a target drive with simple "write parameter" commands

  • The easiest way to do point-to-point motion control
  • Motion acceleration and velocity trajectories are produced by drive and can be set before motion is started
  • Can modify any drive parameter on the fly
  • Can be used together with other setpoint sources
  • No multi-axis synchronization, all axes operate in point-to-point mode individually
No No
Buffered motion commands

List of positions are uploaded to drive command buffers and executed by drives based on clock

  • Allow synchronizing multiple axes and running arbitrary motion paths
  • Motion acceleration and velocity profiles are generated by user application
  • Drives syncronize clocks so motion stays in sync infinitely
  • Typical setpoint update rates are 250 Hz to 1000 Hz for 1 to 4 axis systems
  • Use of Setpoint smoothingCIS smoothens any motion above 250 Hz to silky smooth
  • Delay caused by buffering (0.1-1.0 sec buffering is recommended to avoid buffer underruns and stopping of motion)
  • Update rate will reduce as more axes are added to the system (due to bus bandwidth limit)
No Yes
Real-time motion commands

Position commands are sent to drives just like in parameter communication strategy, except in high update rate and from real-time host

  • Allow synchronizing multiple axes and running arbitrary motion paths
  • Motion acceleration and velocity profiles are generated by user application
  • Use of Setpoint smoothingCIS smoothens any motion above 250 Hz to silky smooth
  • There is virtually no delay between command and action
  • Higher scalability, can use multiple SimpleMotion buses to support large number of axis
  • Update rate will reduce as more axes are added to the system (due to bus bandwidth limit), however, see the scalability feature in Features column
  • For smooth unterrupted motion, need hard real-time host, such as RTLinux, PLC or microcontroller platform.
  • SimpleMotion V2 USB adapter may add uncertainty to timing, so use of other adapter may be necessary (PCI, PCI-E, PLC port or other peripheral, such as microcontroller USART).
Yes Yes

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