Sebastian Kuzminsky <s...@...> writes: ... > > Are you using m5i20 (hostmot) or hm2_pci/hm2_5i20 (hostmot2)?
Sebastian, I am using the m5i20 (hostmot) version at this time. After talking to Peter on the phone today, it looked as if I might be looking for a more mundane problem such as noise and/or signal integrity interfering with the spindle encoder data stream. Sure enough, it took nothing more than a volt meter to ferret out the problem. I was powering the spindle encoder through about 15 feet of ribbon cable, and the voltage drop near the encoder (4.32V) was enough to cause a loss of signal integrity at higher speeds. The encoder is nice older unit with thru-hole components and I am sure that the insufficient Vcc/Gnd was enough to cause some quadrature phase shift, which I witnessed on the scope. Oh well, problem solved! Jeff, Thanks for the info re: the filter being hardcoded in hostmot. Peter and I were wondering about that. There's another reason to start planning to upgrade to hostmot2. Kirk, Yes, I am using a Danfoss vfd, which is capable of switching at very high speeds and comes with excellent ferrites on the motor outputs, and reactor filters on the dc lines, which makes for a big & heavy unit. I checked the motor leads by waving the scope probes near them, and there is a short length of unshielded cable that emits detectable emi, but it is no where near the logic level lines. All the logic/signal lines seemed clean on the scope, but who knows what ultra high freq junk lurks there... I have an older 150mHz Tek 2445, and I could see some "fog" at the small time slices. I re-configured the vfd core switching frequency to a lower 8kHz to see what, if anything that might do, and it didn't seem to hurt or help... it just makes a nice audible turbine-like whine now when the spindle spins up. A huge "Thank You!" to all for following and helping with this. ------------------------------------------------------------------------------ SF.Net email is Sponsored by MIX09, March 18-20, 2009 in Las Vegas, Nevada. The future of the web can't happen without you. Join us at MIX09 to help pave the way to the Next Web now. Learn more and register at http://ad.doubleclick.net/clk;208669438;13503038;i?http://2009.visitmix.com/ _______________________________________________ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
