--- In DynoMotion@yahoogroups.com, Tom Kerekes <tk@...> wrote:
>
> Hi Bengt,
>  
> I'm not sure why you feel you need the Spindle encoder or the Index.  In the video example you sent I don't think there would be any such requirement.  It simply needs to repeat the same angular positions while rigid tapping and then it needed to rotate 90 degrees to mill the "flats".  But if you wish to add them you may.
>  
> To convert 12 or 24V signals down to 3.3V a simple voltage divider may work.  In fact you can mux some encoder inputs to JP4 (see MuxEncoders.c example).  In this case there is an internal 150ohm pull down resistor.  So a series resistance of ~470 ohms to +12V would work.   150/(150+470) x 12V =  2.9V  The output must be able to supply 20ma.  Actually the output drive may just be internally a pull up resistor anyway.
>  
> Regards
> TK
>
> From: Bengt Sjoelund <cnc@...>
> To: DynoMotion@yahoogroups.com
> Sent: Sunday, February 26, 2012 4:20 AM
> Subject: [DynoMotion] Re: JP1/JP2
>
>
>  
> Hi Tom,
>
> Differential encoders on x/y/z + secondary spindle
>
> Lathe? No it is a milling machine with 4:h axis as spindle and A-axis
> Got the idea from here: http://alturl.com/2kri3
>
> So index is needed, question is how to get one with good resolution for accurate positioning?
>
> Encoder at hand for main spindle is single ended 1000lines but HTL not TTL so I have to get the levels down. 9-36VDC voltage to encoder.
> 12 or 24VDC? What do you suggest to do here? Connect to KFlop via JP5 but need to get output levels down to suit KFlop.
>
> Cheers
> Bengt
>
> --- In DynoMotion@yahoogroups.com, Tom Kerekes <tk@> wrote:
> >
> > Hi Bengt,
> >  
> > So it seems you do have differential encoders?
> >  
> > That sounds correct except the series 200 ohms may be too large.  The first 8 IO on JP4 and JP6 have 150ohms termination resistors (pull down).  You probably don't need any series resistor.  With a 150 ohm load most 5V outputs do not go above 3.9V so they can be connected directly.  You could check the output with a voltmeter with a 150 ohm load to see how high the voltage goes.  Otherwise put a 47 ohm resistor to be safe.
> >  
> > Regarding spindle encoder: I think you can get by with the encoder on the motor.  Actually the Index is not even really required at all.  If KFlop is told the exact number of encoder counts per rev of the spindle then that is all that is required.  Unless the absolute position of the spindle is required to be maintained from one power cycle to the next.  Is this a lathe?
> >  
> > You may unplug KFLOP JP5 from Kanalog which will only cause the loss of the differential signals on Kanalog JP2.
> >  
> > I suppose the Analog inputs could be treated as digital signals.
> >  
> > Regards
> > TK
> >  
> >  
> >  
> >
> > From: Bengt Sjoelund <cnc@>
> > To: DynoMotion@yahoogroups.com
> > Sent: Saturday, February 25, 2012 11:37 AM
> > Subject: [DynoMotion] Re: JP1/JP2
> >
> >
> >  
> > Hi Tom,
> > Now I have a better picture of the whole thing.
> > First step is to move (x/y/z) Z signals from JP2 to other inputs.
> > JP1 - 3 for the Main Spindle
> > JP2 - 4 for the Secondary Spindle (A-axis)
> > So now I have 3 differential encoder inputs free for future use.
> > Z signals from x/y/z/spindle/sec spindle to KFlop JP4 with series resistor of 200ohms, right?
> >
> > How can Secondary spindle Index be handled correctly via motor encoder? I think a new encoder must be placed on the spindle shaft for proper indexing and connected to Kanalog and leave the built in encoder for the driver, is this correct?
> >
> > You meantioned JP5 on KFLOP but isn´t it occupied by Kanalog?
> >
> > Still need more inputs for axis selection as well as step selection for the handwheel control as well as the A/B encoder signals.
> > KFlop JP6 will manage these signals.
> >
> > Can the analog input on Kanalog be used for on/off 5V switches if I need more inputs?
> >
> > Cheers
> > Bengt
> >
> > --- In DynoMotion@yahoogroups.com, Tom Kerekes <tk@> wrote:
> > >
> > > Hi Bengt!
> > >  
> > > I'm a bit confused.  Kanalog has differential encoder inputs that must be used with an encoder that has differential outputs (A+, A-, B+, B-).  You cannot just connect to the A+, B+ inputs and leave the complementary inputs floading.  A differential input looks for the polarity of the + and - signals to reverse to signal a transition.  There are low cost converter cables (~$12)  available from USDigital.com and Digikey that can convert single ended signals to differential signals.  Otherwise Kanalog just receives the differential signals, converts them to single ended and feeds them into the single ended KFLOP encoder inputs.  So if you bypass Kanalog you can connect single ended signals directly to KFLOP.  KFLOP JP5 is the most convenient.  You will need to take extra care against noise (shielded cables grounded at the KFLOP end to DC ground and probably some termination of 150
> ohms to ground at the KFLOP end).
> > >  
> > > KFLOP has 8 hardware encoder counters so encoder A/B signals must be connected to those.  The Z signals are handled by software (User Program) and may be connected to any spare input.
> > >  
> > > Regarding the spindle: I would think you can use the one on the motor.  If the driver doesn't have a separate encoder output then just parallel the encoder signals going to the driver also to KFLOP or Kanalog.  The Belt drive reduction will be just as if the encoder had a different resolution.
> > >  
> > > Handwheel encoders are usually low resolution and slow so they don't need to be handled by a hardware counter.  They usually have single ended outputs.  So they can be counted using software and so can be connected to any spare input pins.  See the MPGSmooth.c example.  Usually an MPG only has one encoder and uses a switch to select the axis to move.  It sounds like you have two encoders.  See the Init3AnalogPlusTwoMPGs.c example where two encoders are monitored.
> > >  
> > > HTH
> > > TK   
> > >
> > > From: Bengt Sjoelund <cnc@>
> > > To: DynoMotion@yahoogroups.com
> > > Sent: Saturday, February 25, 2012 6:12 AM
> > > Subject: [DynoMotion] JP1/JP2
> > >
> > >
> > >  
> > > Hi Tom,
> > > I have some questions as regards my need of encoders.
> > > Now I have 3 taken by X/Y/Z (0-1-2 on JP1 + 4-5-6 A+/B+ on JP2 for Z)
> > >
> > > For my main spindle JP1/3 and JP2/7 A+/B+ will be taken.
> > >
> > > So how do I setup my secondary Spindle that will serve as A-axis as well
> > > where I have encoder on AC-Servo, but this unit is geared via belt drive. Do I need another encoder on the spindle shaft or just use encoder on the spindle shaft and disregard the one on motor and have it only connected to the driver?
> > >
> > > Where do I connect the encoder on Kanalog?
> > >
> > > Next is that I have one handwheel encoder in my controldesk, where do I connect this encoder with A/B channels?
> > >
> > > Only free pins are on JP2 A-/B- 4-5-6-7 for two needed encoders.
> > >
> > > Cheers
> > > Bengt
> > >
> >
>