The 7i43 really fits my needs in terms of I/O, cost and from what I've learnt over last few days, performance. I am a LINUX novice so I not sure how difficult the EPP issue is to fix, if its a case of running a .exe to force EPP mode then OK. If its a case of rebuilding EMC by myself then I'm much less comfortable although I'd probably learn a lot.
Andy do you force the RT processes on to one core in your D510MO setup? Andy -------------------------------------------------- From: "James Reed" <jsr...@hotmail.com> Sent: Saturday, October 23, 2010 11:29 PM To: "EMC USERS LIST LIST" <emc-users@lists.sourceforge.net> Subject: Re: [Emc-users] 7i43 or 5i20 > > Yes, but you can have the 7i43 or 5i20 perform the PID calculations. This > offloads the control update rates to the FPGA, and lessens the burden on > the parallel or PCI port. I am in the process of using a 7i43 for a > Bridgeport BTC-1 retrofit, and haven't had any problems with update rates. > >> From: andyi_w...@btinternet.com >> To: emc-users@lists.sourceforge.net >> Date: Sat, 23 Oct 2010 22:42:33 +0100 >> Subject: Re: [Emc-users] 7i43 or 5i20 >> >> Ok, so if I have this right: >> Servo thread periods of 1000us - 2000us are fine for 3/4 axis mill >> cutting >> steel / aluminium with rapids of say 120ipm. Benefit of hardware >> stepgens >> is improved resolution of accelerating / decelerating pulse trains - >> makes >> better use of stepper motors are high rpm. >> >> 7i43 on a parallel port should cope with 1 to 2kHz servo thread BUT there >> is >> an issue with setting the EPP parallel port mode on the D510MO when >> running >> Ubuntu 10.04. >> >> The other option is 5i20 or 5i23 PCI cards which don't have the EPP issue >> but are >x2 more expensive than the 7i43. >> >> Life is never easy :( >> Regards >> Andy >> >> -------------------------------------------------- >> From: "Jon Elson" <el...@pico-systems.com> >> Sent: Saturday, October 23, 2010 7:14 PM >> To: "Enhanced Machine Controller (EMC)" <emc-users@lists.sourceforge.net> >> Subject: Re: [Emc-users] 7i43 or 5i20 >> >> > Andy Pugh wrote: >> >> Possibly. I have read somewhere that a sane (200uS) servo-thread >> >> _execution_ period is only enough time to shift 50 bytes through a >> >> parallel port. That is potentially limiting, but has not been a >> >> problem I have noticed with my 4-axis machine. The software stepgens >> >> running in the base thread and twiddling pins individually are >> >> effectively shifting one word per thread cycle. >> >> >> > At first I was going to take major exception to your numbers, but if >> > your servo loop has >> > to read position, compute PID, etc. and then write velocity out to the >> > device, >> > actually, you may be just about right! Using a PCI parallel port in >> > EPP >> > mode, >> > 200 us should allow up to 250 bytes or so to be transferred, but that >> > would take up >> > the entire SERVO_PERIOD. You have to leave some slack for timing >> > variation, >> > and also for computation. So, the 50-byte figure might be quite close. >> > >> > For my USC board, for instance, there are 4 axes, with 3 bytes of >> > position and >> > 3 bytes of velocity for each. Plus a little digital I/O. So, it reads >> > 14 bytes and write >> > 13, plus setup and control overhead. Total of about 35 I/O operations >> > per servo >> > cycle. You could easily run a 10 KHz servo cycle with 4 axes, or 5 KHz >> > with 8 >> > axes on a modern CPU and PCI parport. >> > >> > Jon >> > >> > ------------------------------------------------------------------------------ >> > Nokia and AT&T present the 2010 Calling All Innovators-North America >> > contest >> > Create new apps & games for the Nokia N8 for consumers in U.S. and >> > Canada >> > $10 million total in prizes - $4M cash, 500 devices, nearly $6M in >> > marketing >> > Develop with Nokia Qt SDK, Web Runtime, or Java and Publish to Ovi >> > Store >> > http://p.sf.net/sfu/nokia-dev2dev >> > _______________________________________________ >> > Emc-users mailing list >> > Emc-users@lists.sourceforge.net >> > https://lists.sourceforge.net/lists/listinfo/emc-users >> >> >> ------------------------------------------------------------------------------ >> Nokia and AT&T present the 2010 Calling All Innovators-North America >> contest >> Create new apps & games for the Nokia N8 for consumers in U.S. and >> Canada >> $10 million total in prizes - $4M cash, 500 devices, nearly $6M in >> marketing >> Develop with Nokia Qt SDK, Web Runtime, or Java and Publish to Ovi Store >> http://p.sf.net/sfu/nokia-dev2dev >> _______________________________________________ >> Emc-users mailing list >> Emc-users@lists.sourceforge.net >> https://lists.sourceforge.net/lists/listinfo/emc-users > > ------------------------------------------------------------------------------ > Nokia and AT&T present the 2010 Calling All Innovators-North America > contest > Create new apps & games for the Nokia N8 for consumers in U.S. and Canada > $10 million total in prizes - $4M cash, 500 devices, nearly $6M in > marketing > Develop with Nokia Qt SDK, Web Runtime, or Java and Publish to Ovi Store > http://p.sf.net/sfu/nokia-dev2dev > _______________________________________________ > Emc-users mailing list > Emc-users@lists.sourceforge.net > https://lists.sourceforge.net/lists/listinfo/emc-users ------------------------------------------------------------------------------ Nokia and AT&T present the 2010 Calling All Innovators-North America contest Create new apps & games for the Nokia N8 for consumers in U.S. and Canada $10 million total in prizes - $4M cash, 500 devices, nearly $6M in marketing Develop with Nokia Qt SDK, Web Runtime, or Java and Publish to Ovi Store http://p.sf.net/sfu/nokia-dev2dev _______________________________________________ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
