Thread: G540Kit + VFD Build help needed

And I'm back again.

After determining the VFD is operating correctly, and my Parallel port and cable are operating correctly, I'm left with the conclusion that either the G540 is faulty, or I've misconfigured it somehow.

I have determined that when I set the spindle speed in Mach3 to 24000, a voltage of about 3.5V is coming down Pin 14 of the parallel cable. I have also determined that my connecting wires from terminals 7, 8 and 9 of the G540 have continuity, and 10V is supplied correctly from terminal 9, when measured against terminal 7, with the measurement being taken at the ACM and +10V terminals on the VFD.

What I cannot figure out is, why, when voltage is applied to parallel pin 14 (the spindle frequency control pin), the G540 is not sending any voltage out of terminal 8 (the G540 PWN control terminal). No matter what I set the spindle speed in Mach3, there is zero voltage coming out of terminal 8, when measured against terminal 7 (ground), and no response displayed on the VFD frequency display.

If anyone can give me a reason my conclusions above may be incorrect, or my testing incomplete, please let me know, otherwise I'll have to wait for Peter to get back from holidays to give me his conclusions.

In the meantime, I guess I can at least set the spindle speed manually and try out some test runs on the machine to see how everything else is working, but ultimately I want the spindle controlled from Mach3.

Thanks. Russell.

One thing, you have set the spindle output to PWM in Mach haven't you?

Originally Posted by Bob Willson

One thing, you have set the spindle output to PWM in Mach haven't you?

Yep.

Use Spindle Motor Output - Checked
PWM settings 50 & 5%

Welcome to 2012 everyone.

My cable to break out the motherboard LPT header to an external port arrived today. Not having progressed anywhere since my last post, I decided to give it a try. So I plugged it in, swapped the parallel cable from the PCI port to this one, started up Mach 3 & all the gear, hit the Spindle button, and up she spins!

So, it appears somewhere along the line, the PCI port, even though it was showing voltage on pin 14, something else was still wrong. The internal port is working perfectly, at long last.

Only wo minor things I could resolve now, but not critical is 1) I have to use the 'run' button on the VFD, can't seem to start it from Mach3, and 2) when stopped in Mach3, the spindle spins down 120Hz at stays there, which is the min freq. setting on the VFD, but how do you completely stop it from Mach3, or can I set the min freq. to 0, since I'm using water cooled?

Now, just gotta get the kids back to school so I have time to play

Russell.

Hi Russell,

Still on Holiday in Port Fairy myself but, you should be able to use a relay connected to the G540 to close and open the FWD contact on the VFD. Then in Mach3 you control that relay by the M3 and M4 setup in the Spindle control tab.

Hopefully that's not too cryptic.
Cheers,

Peter