Thread: Driver wiring advice needed...
Firstly, I must confess to being an electronics dunce. Hmm, probably not just electronics, but I'll stay on topic.
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:
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)
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!
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.
Last edited by JAZZCNC; 19-08-2013 at 05:18 PM.
Just found a bit more info on these drivers over at the Wantai site:
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..!
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!
This thread is handy.... a large package arrived today with some DQ860MAs and a DB25-1205 BOB
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.
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?
Last edited by ruffle; 22-08-2013 at 08:32 AM.
26-08-2013 #9Make sure you set the step outputs in software to active low.
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.
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)
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.
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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