Mc_moveabsolute question

2017-08-06
2017-08-09
  • josepmariarams - 2017-08-06

    Hi all.

    As every plc-codesys manufacturer implements his own plcopen motion libraries which make codesys motion projects not portables, I am developing my own plc motion library.

    My question is.

    I can see that if an fb like mc-moveabsolute (or any other, like move_relative...) Is not executed every cycle when it has the axe control the axe goes to error. Does it be standard mandatory?. If yes, Why?

    For example: If a I am working with sfc, it make me possible to launch an fc_moveabsolute in one step and when the movement beguins transition to another step to do other things. In next step I can control if the movement has finished.

     
  • eschwellinger

    eschwellinger - 2017-08-09

    Hi Josep,
    in general there two solutions to do motion.
    Either the drives calculate the trajectory - you comand it (set where to go how fast and give the start)
    or in case of SoftMotion where you calc cyclic setpoints for all axis -> it is more or less mandatory to have this Kind of supervision of the motion
    calculation (if the fb is not executed anymore-> goto an errorstate)
    BR
    Edwin

     

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