[Mariss Freimanis]

We'll know how well the G540 runs by Tuesday.:-) Here's the G250 preliminary datasheet some have been requesting.

Mariss

[CROSSHATCH]

OMG! I can't wait too buy the 540's!


-Jason

[chafik]

We'll know how well the G540 runs by Tuesday.:-) Here's the G250 preliminary datasheet some have been requesting.

Mariss

Thanks for the latest datasheet. Any chance you could include details on
the input pins (step, dir, enable) and how they are hooked up to the opto-couplers (cathode, anode, resistor value...etc).

Thanks,

Chafik

[chafik]

Thanks for the latest datasheet. Any chance you could include details on
the input pins (step, dir, enable) and how they are hooked up to the opto-couplers (cathode, anode, resistor value...etc).

Thanks,

Chafik

Hate to follow up to my own post, but the G25x have NO optocouplers... Now that I had my coffee I can see the obvious.

Chafik

[Mariss Freimanis]

The STEP and DIRECTION inputs have 3.32K resistor pullups to the drive's 3.3VDC supply. The signals pass through 10K, 100pF low-pass filters on the CPLD Schmitt programmed inputs. Inside the CPLD the signals pass through digital filters before they are applied to the rest of the drive logic. This makes the STEP and DIRECTION inputs noise immune to pulses narrower than 1uS.

If you wish to use external optoisolators, connect the collectors to STEP and DIRECTION, the G250 already has the pullup resistors. The collector current will be 1mA. Connect the emitters to SIGNAL GND (pin 30). This is the drive's "quiet ground" pin. Do not connect the emitters to GND (pins 1, 2, 3 and 4). These pins carry motor currents and are noisy.

Mariss

[yngndrw]

Can the Step and Direction inputs tolerate 5V ?

[CROSSHATCH]

Where are the results! :P....


-Jason

[Mariss Freimanis]

OK, here's the preliminary test results on the G540:

1. Runs fine with 4 axis running 3.5A motors on all axis. Tested from 18VDC to 60VDC. The G540 does get hot; hot enough require a heatsink and/or fan to make me feel more comfortable anyway. I will instrument it with a thermocouple to get a number for "hot".

2. Short-circuit protection works fine. Tested from 18VDC to 60VDC by shorting a motor winding output to ground. The attached thumbnail data was taken at 60VDC. The blue trace is the short-circuit current which peaked a 40A. The yellow trace is the response of the short-circuit protection circuit. It shuts the drives down when it goes to 0VDC (6uS after initiation of short-circuit). The drives respond another 6uS after that for a total response time of 12uS.

3. Inputs and outputs test fine. Maximum frequency response of inputs and outputs is 10kHz measured. Outputs also tested for shutdown on DISABLE input activation and Mach3 charge-pump signal loss.

4. Screwups: Printed on cover axis STEP and DIRECTION DB25 connector pin-outs bear no resemblance to reality except they are DB25 pins 2 through 9. That's it for the screwup list; it's a short one for a change.

Mariss

[CROSSHATCH]

Have you tested them with the Keling KL23H276-30-8B steppers? These are the ones I have.

-Jason

[yngndrw]

Sounds good.

When the drives fault in a short-circuit condition, do they self reset every so oftern or does the power need to be reset ? Same question to when the charge-pump looses it's signal.

[Mariss Freimanis]

yngndrw,

1. Charge pump failure shuts off the drives and the 4 general purpose outputs (DB25 pins 1, 14, 16 and 17) within 5 milliseconds. The G540 will self-restart 1 second after the charge pump starts up again. DB25 pin 1 is assigned as the charge pump signal. The charge pump can be disabled allowing pin 1 to be a normal output. The red FAULT LED lights while the drive is shut off.

2. A short-circuit will shut everything off and will not self-restart. The red FAULT LED lights while the G540 is in short-circuit shut off. Cycling the DISABLE input will clear the shut-off, turn off the red FAULT LED and turn on the Green POWER LED.

3. The DISABLE input shuts off the G540 while the DISABLE input is shorted to GND. The green POWER LED is off, the red FAULT LED is on while in DISABLE. The G540 enables 1 second after releasing the DISABLE input.

4. The G540 enables 1 second after power-up. During the 1 second interval, the drives and outputs are disabled, the FAULT LED is lit and the POWER LED is off. Afterwards the G540 enables and starts operating normally provided conditions in (1), (2) and (3) are met.

Mariss

[Mariss Freimanis]

If anyone can fill me in on how Mach3 handles VFD drives ( if PWM, what frequency, which pin preferred, etc) and maybe the next revision of the G540 can have an optoisolated VFD output as well.

Mariss

[CROSSHATCH]

Have you tested them with the Keling KL23H276-30-8B steppers? These are the ones I have.

-Jason

Mariss, any idea?

-Jason

[Mariss Freimanis]

Jason,

This week is dedicated to proofing out and bringing on-line all the G540 features. Once it's clear everything works as designed then testing can move on to generating speed-torque data on specific motors. Having said that, I have a burned thumb and index finger from foolishly trying to stall the motor you mention while it was turning at 1,500 RPM.:-)

Mariss

[CROSSHATCH]

I'll take that as a good thing ahahah YES!!!!!!

This will be my 1st Gecko purchase.

-Jason

[tauntdesigns]

I'll take that as a good thing ahahah YES!!!!!!

This will be my 1st Gecko purchase.

-Jason

But, not your last!!!!! Once you go GECKO, you'll never go back!!

Jack

[yngndrw]

"Once you go GECKO, you're gonna need a wheelchair."

Mariss: Thanks for your reply, sounds good. I'll have to see if my budget can strech to one of these.

May I suggest as a small and quick product a dedicated charge pump. I.e. A board which just has a charge pump on it, even a kit of parts would do. I noticed that you released a .pdf with two simple circuits for charge pumps but could not find the specific components. I think that there would be a good amount of people interested in such a product.

[Mariss Freimanis]

All you need to do is find the G540 schematic I posted earlier someplace in this thread. Among other things, the schematic contains the charge pump circuit.

Mariss

[yngndrw]

Well it was more for the parts I was personally interested in.

I have the circuit which you produced here:
http://www.artofcnc.ca/ChargePumpSafety.pdf
However I cannot find a local source of these parts. I will have a look at your latest version though, may use easier to find parts.

Edit: In your G540 schematic, there are two diodes which are part of the charge pump - a BAT54. Does it matter what diodes are used here ? Can I use a 1N**** diode in it's place ?

It also seems to label the power and fault LEDs the wrong way around and doesn't show what the transistor in the 12V regulator is connected to.

[tauntdesigns]

"Once you go GECKO, you're gonna need a wheelchair."

How did you know..... Did my SIG give it away. Now, that's funny! lol

Cheers,
Jack