Motion Control drivers and motors

[Gary]

Wiring looks fine, and the current is set to 4.2 A so that should be ok also.
The problem that you are seeing is a typical noise or low signal problem, or possibly both.
These are the points you need to address:

1) Use Shielded cable for all signal cables
2) Shield the motor phase cables.
3) keep signal and power / phase cables apart, and if they need to cross, they should cross perpendicular.


Also check the signals from the pc, the voltage should be about 5V, it it is low the driver can miss pulses and you can get the stuttering you are seeing.

[Gary]

I just had an email from Bruce, and it apears that his clock pulse is about 3.3V, and he is using a laptop.
This is most definately the problems, and is actually quite common when a laptop is used.
The solution would be to use either another laptop with higher voltage outputs, or a desktop PC with a parallel port.

Bruce,
Try this and give us your results.

Thanks

Gary

Aiming for Parallel and don't know what the wiring should be. So any help with be nice here.

Gary from Motion told me that the SW4 was meant only for dropping current down to half after a phase but I'm so lost now I'll try anything.

[irving2008]

I just had an email from Bruce, and it apears that his clock pulse is about 3.3V, and he is using a laptop.
This is most definately the problems, and is actually quite common when a laptop is used.
The solution would be to use either another laptop with higher voltage outputs, or a desktop PC with a parallel port.

Bruce,
Try this and give us your results.

Thanks

Gary

What breakout board is he using? The MDS drivers are optisolated so dont really need a sophisticated BOB and are pretty immune to cross-over noise on the signal lines due to the low impedance 'on' drive. Unless he has a very long cable from PC to BOB or the BOB is a old design with TTL rather than CMOS logic I'd be suprised that the use of a laptop was an issue.

[Gary]

Mot sure about the Bob, but The measured voltage was 3.3V, which is on the border line of working for the optos.
I have found that most support calls that end with the signal voltages being too low were on laptops.

What breakout board is he using? The MDS drivers are optisolated so dont really need a sophisticated BOB and are pretty immune to cross-over noise on the signal lines due to the low impedance 'on' drive. Unless he has a very long cable from PC to BOB or the BOB is a old design with TTL rather than CMOS logic I'd be suprised that the use of a laptop was an issue.

[bruce_miranda]

OK going to try and get my hand on a 'full' PC and see how things go.

Does anyone know of a supplier for a buffered Breakout Board similar to the ones CNC4PC do but in the UK? Hopefully that will give me a full 5V signal and I can use my laptops again.

[irving2008]

OK going to try and get my hand on a 'full' PC and see how things go.

Does anyone know of a supplier for a buffered Breakout Board similar to the ones CNC4PC do but in the UK? Hopefully that will give me a full 5V signal and I can use my laptops again.

Bruce - how are your drivers wired to the PC? The MDS series are opto-isolated. Unless there is some strange wiring issue a higher output voltage wont make any difference as they are active low drive.

[bruce_miranda]

Bruce - how are your drivers wired to the PC? The MDS series are opto-isolated. Unless there is some strange wiring issue a higher output voltage wont make any difference as they are active low drive.

I'm going to give Gary the benefit of the doubt here because he obviously knows his products better than I. So I've bought the only CNC4PC C1G breakboard board that was in stock. Hopefully this will solve my problem. If not then I'm back to the drawing board. Having said that the MSD542 manual does says that its looking for 4-5V for Active High and 0-0.5V for Active Low and since my laptop is giving 3.33V it may not be enought to kick the driver properly

[m_c]

Model Engineers Digital Workshop have a couple of the CNC4PC cards in stock here.

[bruce_miranda]

If I'm aiming for a parallel connection what should the wire colours connected to the driver look like.

[Lee Roberts]

Bruce, have a look at this mate:

http://www.mycncuk.com/pdf/wiring.pdf

That should help you out with the wiring of the bob, check you'v got all that right and then tonight ill give this a bit more time and work out what you need to do.

Lee