[wilcorp70]

I have an AMC B30A40 drive that I just got from their wonderful university outreach program. I am trying to figure out the easiest way to run it in constant torque mode. I am currently using LinuxCNC, but I'm a little unsure of what hardware I need to interface the PC to the drive. I know that the drive uses a +/- 10v control signal, is there a cheap solution to just running a single drive in current mode? I really don't need anything fancy, just my servo maintaining a constant torque.

[samco]

Short of making something your self - I would look at the mesa 5i25. The 5i25 + 7i77 that would be $239ish for the kit.

http://mesanet.com/

That gives you
PCI Anything I/O – 34/ I/O bits LX9 Spartan6 FPGA
6 axis analog servo interface - 48 isolated I/O for 25 pin Anything I/O
And that is expandable.

I don't know if you can get much cheaper than that. (but may be overkill for what you are doing)

You could do a 7I43-P with a 7i33 which gives you 4 analog servo interface and some unisolated i/o for $79+$69 but that is a parallel port interface instead of pci.

Other supported hardware
http://wiki.linuxcnc.org/cgi-bin/wik...orted_Hardware

sam

[wilcorp70]

I can use a parallel port, serial port or pci. I could also possibly build something myself if it wasn't too complicated. I read something about using a DAC with some solid state relays on this forum, but I'm not sure where to find a cheap DAC or how to know if it would be appropriate. That Mesa 7i43-p and 7i33 solution sounds very promising. Honestly, if I could just set the current/torque, I don't even need to interface to the computer if there is some standalone hardware that will do it, I just assumed it would be easier/cheaper.