I used an Advantech ADAM as an isolated RS232/RS485 converter. It's rated for high baud rates.
Like I say, I couldn't find a ground on the X200 that I was supposed to use, not by the manual. The VFD's input does NOT use optos. IIRC I even took apart the VFD, found the internal interface IC, located its ground, and tried to find continuity to one of the input pins- no dice, as I recall. The X200/WJ200, I know they have a target freq and a "target freq locked" bit. But the live actual freq during spin-up, no, I don't know of that being available from a reg. Danny On 3/7/2016 4:14 AM, Gene Heskett wrote: > On Monday 07 March 2016 02:21:53 Danny Miller wrote: > >> Aaaaand that did it! Well, is there any reason to hook that enable up >> to anything? Won't it issue a stop via Modbus if we do Toggle Machine >> Power? (I should have checked that). >> >> I found the code has a bug, it's making a "calculated frequency" by >> multiplying the freq by 100x. But neither the x200 nor wj200 do that. >> They go by 10x (e.g. 100Hz is 100.0Hz and formatted as "1000" on both >> read and write). So it was trying to send impossible frequencies to >> the VFD. >> >> Now when I first hooked up this system under Mach3, the Modbus didn't >> read or write and it turned out to be a problem with massive >> common-mode noise on the VFD, even with no motor output. RS485 is >> differential, but unless it has opto isolating input stages, its input >> IC can't read a signal outside its common-mode range even if the >> differential is fine. > Ouch. The speed of the opto's may restrict performance at the higher > baud rates by causing errors. I'd certainly look at it with a o-scope. > >> I fixed that with an RS232-RS485 isolating converter. At least I >> thought I did. >> >> There's a problem that the X200 has no ground reference to tie the >> converter's RS485 ground to- not that I could find. But it worked >> fine. >> >> The thing is, now that I have fprintf reporting, I DO see that the >> readbits() task fails a LOT when the VFD is decelerating- and to a >> much lesser extent on acceleration. > That I'd suspect would be a direct artifact of the lack of a common mode > reference ground. > >> I suspect there's additional excessive ground noise going on during >> deceleration. Doesn't seem like it's gonna break anything, though. >> >> Danny > I expect that I had better test this vfd & motor I've purchased by > setting it up and driving with with a function generator. I have been > assured by the seller that its quite common to drive its 0-5 volt input > with a high frequency PWM logic signal, its well filtered and will > integrate the pwm just fine. Something the Mesa 5i25 is very good at. > It has a well marked common ground input that should work well. > > But it worries me that I'll lose rigid tapping unless I use it as a > replacement motor so my encoder still functions, so I may wind up > putting it on in place of the slow 1hp, fitting the gear from that > motor, or a replacement of it, to this motor in place of its ER16 chuck. > That will obviously require replacements of all the spindle and back > gear bearings with top quality stuff in order to deal with that whole > gearbox being turned at 6x the speed the existing motor can muster. > Something in the 6x territory if the nameplate speeds are used. That > would give about 13,500 revs for wood carving, a huge improvement over > the 2500 or a bit more that I can get now, using the Pico pwm-servo > driver. Bearing life is a huge ? though. > > That is unless someone can tell me if the speed tally this vfd returns is > actual motor speed, and not just the driving frequency, a question thats > been asked of the vendor and danced around for a reply. So my question > to this list is, has anyone attempted to do rigid tapping by using that > signal as feedback into an a/b/z encoder? Its not available as > quadrature, its a single pin which I believe is a copy of the driving > frequency. > > And I don't believe in magic. Not even when David Copperfield does > it. :) > >> On 3/6/2016 6:01 PM, andy pugh wrote: >>> On 6 March 2016 at 23:46, <dan...@austin.rr.com> wrote: >>>> I'm sure it will- how do I connect it?? Or just get rid of it? >>> Simplest is to "setp pin-name.enable 1" in the HAL file. > Cheers, Gene Heskett ------------------------------------------------------------------------------ Transform Data into Opportunity. Accelerate data analysis in your applications with Intel Data Analytics Acceleration Library. Click to learn more. http://makebettercode.com/inteldaal-eval _______________________________________________ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
