Not all, the 7i90 being a rather glaring exception, it's cheap for it capabilities but needs another $135 in 7i42TA's to protect it. I suspect that any of the Mesa cards that output via 50 pin scsi connectors have similar restrictions.
Yes, the FPGA boards do need buffering but any logic level I/O device needs buffering to control relays etc. You also need to protect inputs. If you want to roll your own I have a design for a Mesa compatible I/O buffer board that has opto isolated inputs and 100mA Darlington outputs that can be configured to drive high side or low side. I/Os are configurable at build time in groups of 8. Each group can be input or output, high side or low side. All thru hole components for ease of hand soldering. I originally designed it as a practice project when transitioning to using Kicad and have used it on a couple of machines now. I've been meaning to release it as open source hardware but never found the round tuits. If anyone is interested I'll knock up some docs and stick it on the wiki page or something.
Les _______________________________________________ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
