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Author Topic: Power Supply for Motion Controlling  (Read 8543 times)

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Re: Power Supply for Motion Controlling
« Reply #20 on: September 23, 2010, 04:41:47 PM »
The voltage(s) that I am measuring are around 3.4, however the fact that I had them running in one direction at least illustrates that the voltage supply is sufficient to power them. Having re-examined the wiring and grounding the common cables again, I sorted out the problem that I was having (Faulty wiring I think0. However a new problem has arose.

For the enable and direction signals that I am sending to the driver I am having no problem, register around 3.4V or so, with the direction going to 0 when the direciton is changed from the Mach3 panel (jogging). Similarly the enable is high when I wish so and disables when I suspend it. However the "pulse" port on my Astrosyn P402, which I have connected to the "step" pin port in Mach3 is staying high even when I try to jog so I am not getting a pulse signal to the driver, only a high or low which does not change unless I change the active high or lo setting.

Put simply, I am not getting a pulse to my driver through pin 5 (direction and enable are pins 6 and 8 respectively). Tried both configurations of active lo (checked and unchecked) still to no avail. Is there another setting that I must assign to enable the pulse train to go from the PC to the driver?. Am getting quite a bit of pressure from people wishing to use the machine also as this is what I need to get it working.

Best regards,
PJ

Offline Tweakie.CNC

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Re: Power Supply for Motion Controlling
« Reply #21 on: September 24, 2010, 02:11:07 AM »
If pin 5 is a problem you could try using another pin number and allocation to see if you have the same problem.

What model breakout board / stepper driver are you using ?.

Tweakie.
Success consists of going from failure to failure without loss of enthusiasm.  Winston Churchill.
Re: Power Supply for Motion Controlling
« Reply #22 on: September 24, 2010, 03:10:22 AM »
The Astrosyn P402. It is optically isolated and am driving three motors on three drivers. I dont think its a pin assignment problem as none of the motors are operating, however the direction and enable works on each just not the "pulse" signal. I am presuming that this connects to the "step" assignment within Mach3

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Re: Power Supply for Motion Controlling
« Reply #23 on: September 24, 2010, 05:11:29 AM »
Hi PJ,

I think we are going round in circles here.

The Astrosyn 402 spec says that it's inputs are TTL compatible (in my book, that's the 5V standard) it does not specifically state that it complies with the 3.3 Volt standard. As I said earlier 3.3 Volt may not be enough to operate some opto-isolators, at least not reliably and I think you should check this point with Astrosyn before proceeding further and looking for problems that may not exist.

You could try using a PC with 5 Volt parallel port or fit a PCI parallel port card with 5 Volt output, either of these two options may solve the problem.

Tweakie.

nb. You are correct - the pulse is associated with step within Mach.
Success consists of going from failure to failure without loss of enthusiasm.  Winston Churchill.
Re: Power Supply for Motion Controlling
« Reply #24 on: September 29, 2010, 07:14:48 AM »
OK, what I have now done is implemented solid state relays between the drivers and the 25 pin D sub. The relays require a 3V input to trigger a max 24V output, which I have connected to the drivers. The problem now seems to be that the pulse width is too narrow for the relays to activate therefore not enabling the drivers to operate. is it possible to raise the pulse width of the signal from 1-5us which is located on the motor tuning tab to well say 100us+?

Offline Hood

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Re: Power Supply for Motion Controlling
« Reply #25 on: September 29, 2010, 07:34:46 AM »
You can set to 40uS pulse width by using Sherline mode. At 25KHz kernel that is half pulse width so basically that is the max Mach will allow you to set.
Hood