Driver wiring advice needed...

[Wal]

Hello,

Firstly, I must confess to being an electronics dunce. Hmm, probably not just electronics, but I'll stay on topic.

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I'm currently working on my driver box and it seems to be going okay (thanks in no small part to Clive.S - a top bloke who has helped me out massively) but as Clive is using a different BOB to me, I thought I'd throw my plans out here to see if I was heading down the right path...

I'm using 3 Wantai drivers (DQ860MA) at 70v along with the free BOB that comes with 'em, which I'm powering from the integrated 5v auxiliary on my power supply.

The first question - if you look at the picture of the BOB - how come there are 2 sets of inputs for the power - my board has them marked as +5V/GND/GND/VDD - or is the idea that you power the board with one set and are then able to take power from the other set?

I know that P1&P2 are intended for XPUL and XDIR respectively. P3&P4 are intended for YPUL and YDIR respectively and (yep) P5&P6 are for ZPUL and ZDIR. I've also been told not to worry about the ENBL+/- pins for my application.

So, with that in mind, will this wiring work:

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Or, should I use P1&P2, P3&P4, P5&P6 to go to the PUL-/DIR- pins of the drivers and then take multiple wires from the VDD terminal to all of the PUL+/DIR+ pins?

Now, to throw the cat amongst the pigeons, I found this post:

LinuxCNC Support Forum :: Topic: LinuxCNC, DQ542MA driver and DB25-1205 BOB (1/1) (http://www.linuxcnc.org/index.php/english/forum/16-stepconf-wizard/26886-linuxcnc-dq542ma-driver-and-db25-1205-bob)

Which looks identical to the set-up I've illustrated in the image above, although it looks like he's re-purposed pin 16 (in Linux CNC) as 'Amplifier Enable' and will use run multiple wires from this pin to all of the ENBL+ pins - what would the purpose of that be, exactly?

What are your thoughts guys?

Cheers - and apologies for the rudimentary nature of my questions!

Wal.

[JAZZCNC]

Ok well don't know this BOB but I'll take educated guess and say that VCC is the positive to power the board and GND is obviosly the ground.
The +5v & Gnd will be a output the BOB provides for powering other things.

Regards the wiring then Yes the diagram is correct and will work. Don't take power from the Vdd to the Pul/dir.

Can't see the Linux link but again I'll take a guess.? . . . Chances are he's done this so when there a Limit or E-stop it disables the drives but doesn't Kill power so the Motors stay Energised and don't lose holding torque, the Enable just stops any signals getting thru.

[Wal]

Cheers Jazz.

Just found a bit more info on these drivers over at the Wantai site (http://www.wantmotor.com/ProductsView.asp?id=271&pid=82):

When the high electrical level is active, all control negative signals will be connected together to GND. When low electrical level is active, all control positive signals will be connected together to public port.

Which I guess translates to:


If your parallel port pulses at 3v then connect all the positive pins on the driver to +5v on the BOB and the negative pins to the control pins (2-7).
If your parallel port pulses at 5v then connect all the negative pins on the driver to GND on the BOB and the positive pins to the control pins (2-7).


Guess I need to test it..!

Wal.

[Jonathan]

Here:

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Make sure you set the step outputs in software to active low.

[Wal]

Cheers Jonathan.

Hmm, so nothing connects to the PUL-/DIR- pins on the driver...?

>Make sure you set the step outputs in software to active low.

How can you be sure that this is the case? Would this not be entirely specific to what pulses my parallel port is sending..?

Oh yeah - PM me your PayPal details for the spindle mounts, man!

Wal.

[Jonathan]

Cheers Jonathan.

Hmm, so nothing connects to the PUL-/DIR- pins on the driver...?

They go to ground.


>Make sure you set the step outputs in software to active low.

How can you be sure that this is the case? Would this not be entirely specific to what pulses my parallel port is sending..?

With this setup, when the parallel port output is low the output of the breakout board is 'open', so the driver pin will be pulled high. It's therefore inverted, hence the parallel port needs inverting to restore normality.

[ruffle]

This thread is handy.... a large package arrived today with some DQ860MAs and a DB25-1205 BOB :friendly_wink:

No documentation of course :) The BOB has jumpers and I've no idea what they do. I'll email the supplier and see if there's any info.

Wal - please update this thread as you go; I'll be one step behind you.

[ruffle]

Found this:

http://www.nbglin.com/download/cnc25.pdf&sa=U&ei=s8YVUsahBsqZ0QW-4IGABg&ved=0CBsQFjAA&usg=AFQjCNH-YdDjXuf1ESHFg63R68R-Yj4h1A

which 'documents' the BOB. It's in terrible chinglish (although better than my Mandarin!). Changing jumpers J1&J2 changes from single to double power supply.

One picture shows VCC, VSS, GND and VDD for the power connector and the other one POWER+5V, POWER-GND, DB25-GND and DB25-VDD for the same connector.

Huh? Now I'm confused. Does this make sense to anyone?

[Wal]

Make sure you set the step outputs in software to active low.

Any idea how to do this in LinuxCNC?

Wal.

[Wal]

Okay, so I connected an axis up using the control pins (2/3) to PUL+ / DIR+ respectively with the PUL- / DIR- going back to the GRND on the BOB.

Nowt.

Set the step outputs to 'active low' - thanks again Clive for pointing out how to do this: check the 'invert' box in the Parallel Port Setup window (Stepconf utility)

Still nothing.

After a fair amount of head-scratching I measured the voltages coming into the PUL+ / DIR+ terminals on the driver - I know that it's gonna fluctuate when the 'test axis' utility is running, but the voltage was peaking at about 2v, both at the driver and the BOB. A bit more head-scratching before connecting the control pins (2/3) on the BOB to the PUL- / DIR- and +5v to the PUL+ / DIR +. Output pins still set to 'active low' and hey presto...

Pics and (rather meaningless, yet somehow satisfactory) video of my motor rotating back and forth attached.

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http://youtu.be/mRMpELNAJNs

Another question - as shown in the diagram here, will it be okay to take the +5v from the PS into a 13amp terminal block and distribute the power to the BOB and the drivers from there? I can't see why it wouldn't, but there's the duncery kicking in again...

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[JAZZCNC]

Another question - as shown in the diagram here, will it be okay to take the +5v from the PS into a 13amp terminal block and distribute the power to the BOB and the drivers from there? I can't see why it wouldn't, but there's the duncery kicking in again...

Yep that will be fine.!!

[Wal]

Hello again.

Sorry to resurrect an old topic - I've been working away from home for a while and am just catching up a bit with bits and pieces of the build. Since my last post, I've come across some instructions for the drivers I'm using, but they're in German - although I think it's probably fairly straightforward to decipher the diagrams if you know what you're looking at.

I've attached a couple of images - one is of the German instructions and the other of the LinuxCNC Stepper Mill config window - the bit I'm concerned with is the "Driver Timing Settings" section.

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I'm led to believe that the German instructions pertain to the "Driver Timing Settings" and this is how the text translates:

Schrittimpuls = Step Pulse

Richtungssignal = Direction Signal

Freigabesignal = Enable Signal

My motors work with the default settings - indeed, they work with a load of different settings, but since this info comes from a German manual distributed by a vendor, it's probably more likely to be correct, rather than me mashing in a load of numbers...

So, based on the diagrams, am I correct in thinking that:

Step Time = 1000
Step Space = 2500
Direction Hold = 2500
Direction Setup = 1000

Any thoughts?

Wal.

[Clive S]

Wal I think you will find if you just use 5000 in each of the boxes it will be fine ...Clive

[Jonathan]

Clive is correct, but if lower values work then your maximum step frequency can be set higher.

[Wal]

Cheers guys - thanks (as ever) for the info!

Wal.

[dazza]

Thanks for posting this wal.
I bought 6 of the same drives recently and received two of those bobs in with em.
Almost a year on hows the bob doing?i dismissed using them after reading a bit of neg feedback but im about to try and wire up my mill so i might give them ago,

[Wal]

Hi deisel,

No problems at all from the drivers or the BOB - the only time I've had a missed step (on one axis) is when I think I may have been feeding too high and spinning too slow on a heavier than usual cut. Other than that everything's worked well with no problems at all. I think Jonathan's used this gear in the past, as has Clive S - both have no doubt moved on to more advanced kit, but for my purposes this gear works well.

Wal.

[routercnc]

Hi deisel, Wal,

For what it's worth I've also just received this simple BoB with the DQ860MA drivers. Little way off setting it all up but will let you know how I get on if I decide to use it.