On 4/6/16 11:12 AM, andy pugh wrote: > On 6 April 2016 at 16:53, hubert <[email protected]> wrote: > >> They currently use drivers that convert step and direction to servo >> control and have BOB that uses usb to talk to the computer. While it >> would be easy for me to just continue using those drivers I am not >> certain that would take full advantage of LinuxCNC. > In principle, sending a pulse-stream as a velocity command is not so > different from sending an analogue voltage. > Do you know what communication methods are available at the drive end? > They sent me a copy of the driver manual but it is going to take me a while to digest its 73 pages. >> I need to determine what kind of BOB to install in the machine that >> both allows them test the machine before shipment and me to easily hook >> it up to my computer when it arrives. > I would be tempted to ask them to check with their normal interface, > then not ship it. But I don't know much about the system. They are going to check it with Mach 3 and then not ship their usb interface. I still have a couple of weeks to finalize the wiring. > >> Also which type on encoder should I ask for. Incremental or Absolute. > Incremental is likely to be easier just because it has been done so > many times. Do you know what the data format of the absolute encoders > is? > I personally like absolute encoders, but then I also like a challenge > :-). Mesa have an interface for SSI and BiSS encoders, but I don't > know of anyone who has actually used them on a machine yet. The servo comes with an embedded Incremental encoder so for the time being I will stick with that. Intuitively I like the idea of absolute better, but if I have a functional system to work with I could play with different encoders at a later date.
Thanks for the answers, It gave me enough to come up with a game plan. I decided to go with the Mesa 7I76-6I25 PNG kit. I will start working with that to give me some experience. At this time I don't have any servos on hand but I do have steppers and encoders so I can start playing with a feedback loop, HalScope etc. To date I have only used steppers with Gecko drivers through a parallel port with software stepping. The US distributor of the mill also ordered the same Mesa set and plans to take it back with him to China when the get to the testing phase so they can try things before shipping. He has interest in offering a LinuxCNC solution as well their other control solutions. ------------------------------------------------------------------------------ _______________________________________________ Emc-users mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/emc-users
