2017-02-03 23:05 GMT+02:00 Peter C. Wallace: > You need a RS-422 interface to connect a sserial device to the FPGA, so > 7I44, > 7I52, 7I47, 7I47S, or RS-422 interface chip on a little board like our > 485X1 > for just one channel >
> But if you only have the OPTO racks and the step/dir pins, you should not > need > and sserial I/O expansion (unless it makes wiring easier to have the OPTO22 > interface at some distance from the 7I80) > Yes, I think I don't really need sserial... > If its sinking current, yes, you can get 5V swings (so OK for drives with > common +5 on the Opto inputs) if sourcing, it can only swing to 3.3V or so > which is not so good. > Good for me, the desired drives have common +5V. > > Note that if you use bare FPGA I/O, a single wiring mistake will ruin your > day... > Sure, that's a risk... I would take 7i47S if I needed an analog output... or 7i47 if I needed encoders. 7i42TA would do the job either? Andrew ------------------------------------------------------------------------------ Check out the vibrant tech community on one of the world's most engaging tech sites, SlashDot.org! http://sdm.link/slashdot _______________________________________________ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
