Rob Antonides wrote: > Hi, > > I would like to use one of Mesa's FPGA cards to drive 8 stepper axes. I > would ideally use 4 of their 7I32 stepper driver cards to drive all 8 > steppers. This is for a 6 axis hexapod with a rotary axis on top and > another stepper for extrusion. > > >From what I understand EMC2 only supports EPP or PCI. I also need at least > 4 50 pin headers to connect to the stepper daughter cards. > > This leaves me with the 5I22. > > Is the 7I60 also an option? I don't think so because it only has serial > ports. The 7I60 is a nice solution for me, because eventually I would like > this to be a standalone controller with the motion control program right on > the FPGA. Is the Xilinx WebPack easy to program with? Does someone have > experience with this? > FPGA programming is quite different from traditional computer languages. In nearly all computer languages, one small step is performed on each line of code. With FPGAs, in many cases, EVERY line of code is executed on every clock cycle of the FPGA. This makes them very powerful, but there are also many conditions that you have to be very careful with, or you will have a BIG mess. I have made a ramping one-axis positioning controller with an FPGA, and after resolving some dumb errors and faulty assumptions on my part, I did get it working. If you want complex arbitrary motion of a hexapod all in an FPGA, I think you are asking for big trouble. The only sane way to do that is with a very large FPGA with a power PC core on it, and run Linux on that CPU. Be comfortably seated when pricing one of these larger Virtex parts! Preferably, have someone standing by with smelling salts. Suddenly, a PC sounds like a very reasonable solution. Anyway, if you are not skilled in digital logic design, you will find the transition to VHDL or Verilog has MANY pitfalls that you had no idea existed. Also, you can't just put in a print statement to find out what is going on in an FPGA - you need at least a digital storage oscilloscope and most likely a logic analyzer.
Two of my universal stepper controllers and your choice of Gecko stepper drives would also work, but at greater cost than the Mesa products. Jon ------------------------------------------------------------------------------ Crystal Reports - New Free Runtime and 30 Day Trial Check out the new simplified licensing option that enables unlimited royalty-free distribution of the report engine for externally facing server and web deployment. http://p.sf.net/sfu/businessobjects _______________________________________________ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
