Private message regarding: Tutorial - VXM - Get Position / Get Position "On-the-Fly"

[Le Pham]

In case I need to get X-position quite often while the motor is in motion, up to several times per second, are there any other options?

Thanks, Le

On Thursday, August 22, 2013 at 11:58:12 AM UTC-5, Velmex Controls wrote:

Description:    How do I get positions from the VXM? Can I get positions while the motor is moving?

    Typically to get position you would send one of the following commands
    These commands are considered "Immediate" commands, meaning they are not part of a program, for example
    "F,C,I1M1000,X,R"     =    Position would return at some point within the first few steps of the movement
   
    Commands for motor position
    X    =    Motor 1
    Y    =    Motor 2
    Z    =    Motor 3
    T    =    Motor 4
   
   
    Typically motor positions are read while the motor is stopped for things such as data-acquisition,
    but positions can be read while the motor is moving (Motors 1 & 2 only), but should only be done for display purposes.
    The problem being that due to communication baudrates the position retrieved is not repeatable (meaning that if you performed
    the same movement 3 times and read the position, then you would most likely get 3 different answers. Also the motor is no longer
    where it was when you asked the position.
   
    It is also important to not ask for position too often for the following reasons
        I.) It could induce a "Buffer Over-flow" problem (user over flows the VXM buffer by sending another request while the
            VXM is still responding to a previous request)
        II.) It could cause the VXM to lose synchronism and the motor will stall