Just a short addendum. The 7i92 manual says the outputs are capable of sourcing 24mA. Putting a 330 ohm resistor to ground onto pin 1 of the Probotix BoB will sink 15mA when the 7i92 outputs a high level so it's within spec. When the 7i92 goes inactive which it seems to do when LinuxCNC shuts down the resistor pulls the output low. Since Pin1 is my system enable the Probotix BoB now sees it as low and drives a logic low out to the Bergerda Servo Enable and the motor now stops. As it should when Linux stops.
I could probably use a 510 Ohm resistor and cut that back to less than 10mA. Still prefer a Charge Pump but this little Probotix board https://www.probotix.com/BREAKOUT-BOARDS/PBX-RF was always meant for simple stepper based CNC routers so it's not surprising that they wouldn't have dealt with this issue. Just something to be aware of when building up a system. John > -----Original Message----- > From: John Dammeyer [mailto:jo...@autoartisans.com] > Sent: June-14-21 8:53 PM > To: 'Enhanced Machine Controller (EMC)' > Subject: Re: [Emc-users] all the MESA cards talk made me think > > Hi Ron, > Well other than the rather annoying motor start-up when LinuxCNC is stopped > issue the reason for the test set is to now install a > different BIT file into the 7i92H, use a slightly modified to replace the > PWM/DIR with stepper. > 14 1 IOPort StepGen 5 > Step/Table1 (Out) > 16 5 IOPort StepGen 5 Dir/Table2 > (Out) > > And then set a couple of parameters in the Bergerda to use pulse for speed > rather than 0-10V. I don't have to change anything in > the little yellow box. It's already configured to deliver differential > stepping and direction signals to the Bergerda. The 0-10V is on a > separate connector and Analog direction is on a different pin. > > If that works then I don't need the 0-10V module anymore. The problem before > was StepGen5 was on the second parallel port and > the Encoder0 was on the first plus it stepped on the standard ESTOP DB25-10 > pin. So now I can add an encoder to the mill spindle > and run this slower than about 150 RPM. > > More when it happens. > John > > > > -----Original Message----- > > From: R C [mailto:cjv...@gmail.com] > > Sent: June-14-21 8:40 PM > > To: emc-users@lists.sourceforge.net > > Subject: Re: [Emc-users] all the MESA cards talk made me think > > > > that's ool.? Once I clear out my "work bench" a bit,? I might et up a > > few things,? possbly even with an RPI4 or so, and just test some setups. > > > > > > I wonder if I have more fun playing/messing with these CNC machines the > > actually doing stuff with them? (which I want to, I have that telescope > > project too). > > > > > > Ron > > > > > > On 6/14/21 9:27 PM, John Dammeyer wrote: > > > Here's my test setup. > > > > > > from left to right. > > > 1. MESA 7i92H connected via Ethernet to the Pi4 1Gb sitting under my > > > monitor. > > > The Pi is running LinuxCNC. > > > 2. Probotix Break out Board and although it could be isolated I'm using > > > the same 12V supply for both sides with the BLK/WHT > > twisted wires. > > > It generates the 5V to run the MESA 7i92H. BLK/RED twisted wire. > > > 3. The PWM Spindle Control board I pulled from the mill because I was too > > > lazy to assemble another one for this testing. > > > It too is powered from the 12VDC adaptor (actually more like about > > > 16V) Grey jacket cable to black connector. > > > This holds the little PWM to 10V module and is driven by the BoB via > > > DB25 pins 14-PWM, 16-DIR and 1-ENABLE > > > 4. Bergerda AC Servo showing that it's running the motor at 558RPM which > > > I set from the LinuxCNC buttons. > > > > > > Now the first surprise when I stopped the LinuxCNC program. I've been > > > spoiled by the ChargePump on the PMDX-126 BoB I use. > > With this small Probotix board the program stopped and the parallel port > > output pins all went high. Not a problem for a stepper > > motor. Big issue when the PWM input thinks that is 100% and the ENABLE > > signal which is active high goes high. Motor started > > turning at full speed. > > > > > > I'm not surprised. So many of the Break Out Boards out there are > > > designed only with stepper motors in mind but in this case this > is > > the spindle. This enable signal would also run a master power relay which > > would also stay on after LinuxCNC went away. Not > good. > > > > > > With the Charge Pump gone the Break Out Board automatically disables > > > outputs so they can't source current out to a drive and it > > definitely switches off any relays on the BoB. So not too impressed with > > this small BoB. > > > > > > Or maybe the issue is with the 7i92? Perhaps on loss of communications > > > with the host it should set the outputs low. It's looking > > like it sets them high since the PWM output was 0 and the ENABLE output is > > also LOW set by the "Toggle Machine Power F2" > button > > on the user interface. > > > > > > > > > > > > > > >> -----Original Message----- > > >> From: R C [mailto:cjv...@gmail.com] > > >> Sent: June-14-21 8:14 PM > > >> To: emc-users@lists.sourceforge.net > > >> Subject: Re: [Emc-users] all the MESA cards talk made me think > > >> > > >> > > >> On 6/14/21 3:50 AM, andy pugh wrote: > > >>> On Mon, 14 Jun 2021 at 02:16, R C <cjv...@gmail.com> wrote: > > >>> > > >>>> I have seen the 7i92? mentioned, and others,? can they do multiple > > >>>> stepper motors?? (right now I am using a parallel BOB,? that connects > > >>>> to? steopper drivers (ala DM542), which drive the actual steppers.) > > >>> The Mesa FPGA card replaces the parport card, and in some cases also > > >>> replaces the BoB. > > >>> > > >>> The 5i25 and 7i92 replace only the Parport card and would retain the > > >>> same BoB. They can both be used with the same BoB as you currently > > >>> use, or you could use a 7i76 (probably overkill) > > >> right I have been looking at some.? I don't mind using existing BOBs, > > >> since I have several, and since I am not really running high-tech, > > >> industrial stuff..? it shouldn't be too expensive. > > >> > > >> (I saw some between 50-100 bucks, that would work (?) > > >> > > >> > > >>> Alternatively you could look at a 7i96 or 7i76E which both connect to > > >>> the ethernet port and replace both the parport card and the BoB. > > >> I'll look into those too. > > >> > > >> I wonder how these things need to be programmed though, John explained > > >> some of that.? I think in a bit, when I have more time, I? just buy a > > >> few and just jum in (but build a test setup first. > > >> > > >> > > >> Ron > > >> > > >> > > >>> There are not any PCI cards which also directly replace the BoB, and > > >>> none that replace the stepper drivers. > > >>> > > >> _______________________________________________ > > >> Emc-users mailing list > > >> Emc-users@lists.sourceforge.net > > >> https://lists.sourceforge.net/lists/listinfo/emc-users > > >> > > >> > > >> _______________________________________________ > > >> Emc-users mailing list > > >> Emc-users@lists.sourceforge.net > > >> https://lists.sourceforge.net/lists/listinfo/emc-users > > > > _______________________________________________ > > Emc-users mailing list > > Emc-users@lists.sourceforge.net > > https://lists.sourceforge.net/lists/listinfo/emc-users > > > > _______________________________________________ > Emc-users mailing list > Emc-users@lists.sourceforge.net > https://lists.sourceforge.net/lists/listinfo/emc-users _______________________________________________ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
