[Vatorman]

Hello
I have an SX3 converted with x4 electronics working in manual mode but am trying to figure out wiring to work with A Gecko g540 for the spindle control.
On the spindle board it has 7 pins which are +12v, +5v, none, none, F/R, PWM, GND. How can I make this work with g540.
Any suggestions would be great.

[Vatorman]

Here are some pictures of the x4 mother and daughter board.Attachment 212286 Attachment 212288

[TangentAudio]

Your photos didn't work for some reason.

I haven't seen or used the X4 electronics myself, but from the sounds of the pin labels it shouldn't be that hard. The PWM signal should be the input to the X4 board to control the speed. The F/R is probably the forward/reverse signal. The voltage pins (+5, +12V) are probably power output from the X4 board. You could confirm that by measuring from GND to the pins with a multimeter on DC volts mode. For that matter, I'd be curious to know what voltages you measure on the PWM and F/R signals as well. It could help me answer some questions.

You need to figure a few things out:

- What voltage levels is the X4 board expecting? It may only be 5V logic, and it simplifies matters if it is.
- Does your control logic need to be isolated? Many drives can't share a ground reference with your control logic, or bad things happen. If you can get a clear, high resolution photo of the board posted I might be able to help you figure out if it's got optoisolators on it already.

I took a quick look at what the G540 offers. It looks like it's set up to provide an isolated 0-10V analog signal, which isn't very useful if the X4 board has a true PWM input.

However, it looks like they use pin 14 of the parallel port to create that 0-10V signal with a PWM output from your control software. You should be able to pick off that pin from the DB25 connector and use it, perhaps with a little bit of interface logic if necessary, to feed the X4 board's PWM signal.

You can probably also use the G540's OUTPUT 1 or OUTPUT 2 signal to drive the F/R signal, providing you're not already using them for something else. You may do it directly off of the parallel port pin, or you could do it using one of the G540 relay outputs which are provided for you.

Once you get it working, you will also want to think about a way to provide a good, safe emergency stop solution. But you can cross that bridge a little later.


How comfortable are you with electronics? You may need to build a small circuit with a few parts to make this work.

[Vatorman]

I'll see if can upload some better photos

As for voltage readings to ground
12vdc= 0,
5v= 4.5,
PWM =4.5,
F/R =4.0
I believe the board is optoisolated but I will show some pictures to verify, Looks to be there are optos on both boards but not 100% sure.
I have no problem with electrical being I troubleshoot elevators for a living (relay logic,solid state,I/O,etc) Just not familiar with this animal, and having no prints or manuals doesn't help, so definitely comfortable, but don't wont to fry anything. Plus I've seen some of your videos and you seem to be very knowledgeable in this area.
Thanks

Attachment 212448
Attachment 212454

[TangentAudio]

That definitely looks promising.

I believe all of those white IC packages are optocouplers. The A7840 on the right definitely is, but I can't read the other ones. They're in the right place on the board to be providing isolation, and optos are quite often encased in white epoxy like that. If you can give me the numbers on the four smaller 4-pin chips and the other 8 pin chip I can verify.

The voltage measurements look promising as well. I see one of the pins is labeled "Run/Stop" .. You will probably need to use that as well. Can you measure the voltage on that pin?

The 5V rail is measuring a bit low, but since the PWM pin measures the same I think it's pulled up to that "5V" rail through a resistor. This is a good sign, it tells me it's most likely designed to work with 5V logic.

If run/stop also measures out at about 4.5 volts, it looks like it's all active low logic. If this is the case, your first experiment would be to see if the motor runs if you short the run/stop pin to ground.

If it doesn't run, it may be because a high input to the PWM input may mean "0% speed" where a low may mean "100% speed". You could try grounding PWM and run/stop at the same time in that case to see what happens.

If it does run just by grounding run/stop, then we know the logic on the PWM input is 100% speed with high, 0% with low. Pulse Width Modulation (PWM) on that signal is what gets you the range in between 0% and 100%.

Let me know how that test goes then we can see where to go from there.

I think you'll probably be able to drive this directly from some parallel port pins. It also looks like you may be able to get an error output back into your control as well - that is a good idea if you have the pins to spare, since it's nice to halt the axis motion if the spindle motor faults.

[Vatorman]

I measured voltage to gnd with spindle in off state 0 rpm and with it being mid rpm 2500 and max at 5000. to see any change. Not significant change +/- .01v.
And also I am using both outputs on the gecko for mist/coolant to some relays for the pump and solenoid. Also using An auto zero probe tool connected to an input.
Also forgot to mention that I run a usb smooth stepper. Is it possible that the x4 board can go to the smooth stepper instead of the gecko. Dont know a lot about the ss just that its worked out great.

[Vatorman]

The smaller packs are all .042
P181
YE
Large one is 1036
TLP250

[TangentAudio]

It looks like the Smooth Stepper has a second port that you might be able to use to get this hooked up. I assume you have your G540 connected to "Port 1" on the Smooth Stepper board?

I assume you're probably running Mach? I can't help much there unfortunately, though it shouldn't be hard to figure out if it supports both ports on the SS.

[TangentAudio]

OK, those are all optoisolators. Good sign.

[Vatorman]

I have a spindle switch on the console wired in and its for manual and cnc mode. enabled that and tested run/stop to gnd and no movement.
Shorted PWM to GND and i get a burst of movement then nothing until i repin and another burst.
PWM to run/stop no movement.

[TangentAudio]

The burst of movement may be a good sign, but the controller may need to see some pulses and not just a constant high or low signal.

Do you have any electronics lab equipment, like an oscilloscope and a function generator? A function generator configured to output a 5V square wave would be the quick way to test it.

If you don't have any bench gear to do it, the next best thing will be figuring out how to configure your software to generate the signals and put them out on one of the Smooth Stepper pins. Mach (or any other software, for that matter) should have no problems generating a PWM output, you just need to figure out how to configure it to do so. An oscilloscope would come in handy to know that's working, though another way to test it would be to output it on that pin that the G540 uses for its VFD 0-10V output. You could measure the 0-10V output with your multimeter to know if it was set up right.

[Vatorman]

Unfortunately I don't own an O-scope or a function generator. Might be able to get one from work but might be a hassle. So your saying connect the g540 terminal 9 (VFD IN), I believe i have look for the print to verify, And configure in mach and check voltage 0-10v.

[TangentAudio]

Unfortunately I don't own an O-scope or a function generator. Might be able to get one from work but might be a hassle. So your saying connect the g540 terminal 9 (VFD IN), I believe i have look for the print to verify, And configure in mach and check voltage 0-10v.

Pin Number
1 INPUT 1 (DB25 PIN 10)
2 INPUT 2 (DB25 PIN 11)
3 INPUT 3 (DB25 PIN 12)
4 INPUT 4 (DB25 PIN 13)
5 OUTPUT 1 (DB25 PIN 17)
6 OUTPUT 2 (DB25 PIN 1)
7 VFD GROUND
8 VFD OUTPUT
9 VFD +10VDC
10 DISABLE INPUT (E-STOP)
11 SUPPLY +18 – 50VDC
12 POWER SUPPLY GND

Those are on the green screw terminal block on the G540. You will want your meter black on VFD Ground (pin 7), red on VFD Output (pin 8), and set up to measure volts DC.

Then, do whatever you need to do in Mach to get it to output spindle speed on pin 14 of the parallel port. The G540 has a circuit inside to convert the PWM output from that parallel port pin to a variable DC voltage, and it also has isolation circuitry. You'll know it's working right when you can get different voltages on the voltmeter by varying the spindle speed in Mach. It should go from 0V at 0% speed, 5V at 50% speed, 10V at 100% speed, etc.

Once it's working, you can unplug the G540 and use the parallel port pins directly... pin 14 will go into the PWM input on the X4 board, and any from 18-25 is GND and should connect to the GND next to the PWM pin. You'd still need to do the run/stop manually, but it would at least let you get PWM pulses into the controller.

[TangentAudio]

Also, I'm wondering if that pin labeled "AVI" is Analog Voltage In on the X4 board... But it's harder to know what the safe voltage range is. I'd stick with this PWM plan for the moment.

[Vatorman]

I'll get back to you and let you know what happens. You've been a huge help thanks for the assistance.

[TangentAudio]

How's it going, Vatorman? Any progress?

[Vatorman]

Been super busy lately haven't had much time. I should have sometime possibly tonight or this weekend to do some more testing.

[Vatorman]

I've been having some trouble getting an output 0-10v from my g540. I have gone over all pin outs and outputs possible in mach3 and smooth stepper config. to my knowledge and still can't seem to get anywhere. I may have a bad vfd output on the g540. All variables and i get no voltage.

[Vatorman]

I did jump a 9 volt battery across pin 7 & 9 and got 9.5v across 7 & 8 so I believe that the gecko is ok. It must be something in mach. I'll have to figure that out first before going forward.

[Vatorman]

OK, I finally got my new g540 hooked up and tested. Testing through mach also and all is well. Here is what I did to test through mach to verify gecko is working.
9 volt battery test went like this.
Main Terminal Block (gecko)
pos 7 vfd ground ---- -9 volt
pos 8 vfd output -----------
pos 9 vfd+ 10vdc ---- +9 volt

Then I ran mach 3 spindle to 5000 rpm's (100%) and tested pos 8 output and pos 7 gnd. and got 9.23vdc and at 2500 rpm's (50%) at 4.68vdc.
I will be sending the original g540 back to gecko for repair since the vfd i/o was not working correctly and just have a backup.

Since I got that going, now I can move on to try and setup the X4 spindle board to work with the g540.