Igor Chudov wrote: > I was working on adding a spindle encoder to make my Bridgeport Interact 2 > mill capable of rigid tapping. > > I finally added one today, and it works on a basic level, as in, EMC2 gets > the encoder value through Jon's PPMC. > > I am concerned with whether the readout from the encoder is accurate, or, > perhaps, it is missing some pulses due to some mistake of mine. > > The idea that I have is to run the spindle for, say a minute, and then > compare the count of index pulses with the value of spindle position. They > should be close within one, I think. > > I already get the encoder float value as ppmc.0.encoder.03.position. How do > I get index count? > > Unfortunately, there is nothing counting index pulses. > The encoder does output index pulses. > Yes, but the pulses are very short, and the sample rate is your servo loop rate, so you are likely to miss them. (Hmmm, actually, there is a LATCH that holds the index until the register has been read, so maybe the previous sentence is not true!) You should be able to rig a counter in a HAL component to count every time the index is 1. Because of the edge-triggered latch, it should always reset after it is read, so it will only show 1 for a single sample. Run a while, stop spindle and compare the counter output with the accumulated encoder position.
Jon ------------------------------------------------------------------------------ Lotusphere 2011 Register now for Lotusphere 2011 and learn how to connect the dots, take your collaborative environment to the next level, and enter the era of Social Business. http://p.sf.net/sfu/lotusphere-d2d _______________________________________________ Emc-users mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/emc-users
