[M Kiser]

Hello, I'm new to cnczone and am hoping that I can get an answer to a problem I'm having with my new Gecko 540.

I have it hooked up to a PC running Mach3. After quite a bit of messing around with configuring Mach3 I have it to the point that the steppers drive the slides just as the program tells them to. Outputs 1 and 2 however aren't doing so well. I hope to turn on a laser with an M03 and turn on shielding gas with M08. When the program runs, I measure voltages of 8 and 16 volts at terminals 5 and 6. My supply is 42 volts. Isn't that what I should be getting between the outputs and the positive terminal of the supply? When I connect a relay the voltage reading is zero and the relay does nothing at all.

Am I missing something?

[Khalid]

post wiring diagram, pls.

[john-100]

Hi

the G540 outputs can only sink current to terminal 12 and
don't supply any current from the positive supply terminal 11


Attachment 222818

you need to ensure the external circuit will limit the current to a maximum of 1A
and voltage to 50V


John

[M Kiser]

What exactly does "sink" mean? I've been assuming that it meant providing a current path to ground in this case. Is that wrong? I'm measuring the voltage between terminal 11 and terminals 5 and 6.

Thanks for responding.

Khalid, I'll see what I can do about a diagram.

[john-100]

you are correct in thinking the outputs only provide a path to ground
the G540 output circuit acts like a switch between the output terminal 5 or 6 and the ground terminal 12

when the output is switched on
current flows from your positive supply via the external load ( relay coil or what ever )
then INTO the G540 output terminal and then to G540 ground terminal 12

if your using a 48v relay that operates with a 42V supply
like this relay http://docs-europe.electrocomponents...6b80fa7aee.pdf

you just need to connect one end of the coil to + 42V and the other to the G540 output

the voltage between ground and the output should be +42V until the output is switched on
it then should drop to 0V


John

[Al_The_Man]

What exactly does "sink" mean?
.

Sink or Source here.
Al.

[M Kiser]

So it sounds like sinking is when it is switched on the negative side of the device and sourcing is when it is switched on the positive side. Why don't they just say that?

[Mzones]

So it sounds like sinking is when it is switched on the negative side of the device and sourcing is when it is switched on the positive side.
Why don't they just say that?

NO ! You not getting it.

I'm measuring the voltage between terminal 11 and terminals 5 and 6.

Why are you doing this?

Mike

[M Kiser]

My intention was to test outputs 1 and 2. Is that not the right way? When I MDI an m3 or m8 command I look for voltage at the outputs. Which I get. Just not the full 42V of the supply. More like something in between 42 and 8V which immediately drops to 0 when a load is applied. The relays don't do anything at all.

[ger21]

You need to measure at terminal 12, not 11.

[Khalid]

connect/touch G540 output to ground and see the behaviour of that output pin in mach3 diagnostics. If it blinks that means your output is good. Actually G540 output is 12V DC already optoisolated inside the G540. You only need to ground it to get it working. This depends upon how you ground it.

[Khalid]

And dont forget..All powersupplies and G540 grounds (DC) must be interconnected.

[M Kiser]

You need to measure at terminal 12, not 11.

With outputs on, the voltage between the output terminals and terminal 12 is 0. With outputs off, voltage is about 1.5.

[tjb1]

connect/touch G540 output to ground and see the behaviour of that output pin in mach3 diagnostics. If it blinks that means your output is good. Actually G540 output is 12V DC already optoisolated inside the G540. You only need to ground it to get it working. This depends upon how you ground it.

Why would the output show anything in Mach3 when grounding it? Does the G540 not pull the output to ground when activated and floats it/goes high when de-activated? Your post sounds like the procedure to test an input, not an output. To test output, you would activate with software and test continuity to ground.

[M Kiser]

connect/touch G540 output to ground and see the behaviour of that output pin in mach3 diagnostics. If it blinks that means your output is good. Actually G540 output is 12V DC already optoisolated inside the G540. You only need to ground it to get it working. This depends upon how you ground it.

Thank you for your response.
I grounded the outputs and the diagnostic lights in Mach 3 stayed off. Should they come on? How can Mach3 sense this?
Regarding a 12V output, I was under the impression that the G540 did not provide a voltage but only made the connection to ground. Does it actually have a 12V output?

[Khalid]

Sorry..tjb is right..Kiser please follow TJB advice..First check your Output pin rightly configured in Mach3.. Also show pictures of wiring with G540 (not the sketch but actual picture)..G540 has not tagged with output/input pins at its connector so be careful..

[M Kiser]

Why would the output show anything in Mach3 when grounding it? Does the G540 not pull the output to ground when activated and floats it/goes high when de-activated? Your post sounds like the procedure to test an input, not an output. To test output, you would activate with software and test continuity to ground.

I just activated both outputs in Mach3 (the lights are on in Mach3 diagnostic) and the resistance between ground and terminals 5 and 6 is 0.3 and 0.6 mega ohms.

Upon turning off the outputs in Mach3 they are completely open.

[Al_The_Man]

So it sounds like sinking is when it is switched on the negative side of the device and sourcing is when it is switched on the positive side. Why don't they just say that?

It can get a bit confusing, they way I prefer to think of it is both in terms of the input terminal and the device connected.
IOW, with a Sink input, the device or switch must provide the Source power +ve, in the case of a source input, the input switch or device has to sink the input to Common.
Al.

[M Kiser]

Yes it is confusing!

I just got off the phone after talking with the designer (!) of the G540. He asked if the charge pump switch could be turned on without causing a fault. When I told him it could not, he said that most likely the problem is that the PCI parallel card doesn't do EPP mode. Even though the BIOS is set for EPP, many cards are not set up for it. Does anyone know of a parallel card that is known to work with Mach3 and the G540?

While talking to him, I discovered another problem with my system. It turns out that the formula in the Gecko stepper motor manual that is used to calculate motor voltage does not apply to NEMA 17 motors. 42V is much to high and 24V will give more than enough speed. I sure wish that little tidbit had been in the manual so I wouldn't have thrown money away on the wrong power supply!

Looks like it's time to spend some more money!

[M Kiser]

Well, after a lot of messing around it finally seems to be working! I installed a parallel card from Practical Micro Design (PMDX-2PARPCI) that let the parallel port work the way that the G540 needed for it to work. I was pleased with tech support as well. Very friendly and knowledgable. I now have a working charge pump and outputs!

So, the bottom line seems to be that pci parallel port cards usually don't adhere to the original standard. PMD stepped up and fixed a problem that perhaps Gecko should have addressed in their own self interest. If you do a search "outputs not working in mach3" or "charge pump not working" you will get an idea of the number of people that are all having problems related to the PCI parallel cards that don't conform to the IEEE standard.

Thanks for the Help!