Messages

3561

PoKeys / Re: Pokeys, mach4 no go?!

« on: October 11, 2018, 03:27:55 AM »

Hi,

MM is brand new so it shouldnt be shorted, but not really a top of the line fluke Smiley 

Doesn't need to be.

Read in the manual for it now, if measuring up 40mA the resolution is 10mA so it seems it wouldnt be able to read out 8mA then

That doesn't sound right. If a meter can read 40mA then it should have uA resolution. Post the manual. If that meter is not right or good
enough beg steal or borrow one that is. You also need some way to confirm its working. Either way we need that measurement otherwise we
are just guessing.

Craig

3562

General Mach Discussion / Re: 4axis-TB6560hq

« on: October 11, 2018, 02:26:12 AM »

Hi,
I am sorry to say that these Chinese made boards are very often unsupported. They are awfully quick to get your money but China
might as well be another planet when it comes trying to get manuals/help or anything.

Are you in a situation you can return it because the supplier doesn't have a manual?

Craig

3563

PoKeys / Re: Pokeys, mach4 no go?!

« on: October 11, 2018, 02:13:33 AM »

Hi,

What can cause my signals to not possibly be strong  enough? Faulty board?

No, I don't think its a faulty board, and I think its close enough to work as intended, we would know for sure one way
or another if you would only measure the current!

These are from the PoKeys 57CNC manual, I assume you have it?

On page 16 is the listing of the pin types in the motor output header, note all three outputs are of type DO_5.

On page 18 is a representative circuit of the DO_5 type output. The signal originates in the MCU and is buffered, that is the triangular symbol,
the current passes through the 100 Ohm resistor. PoKeys have put the resistor in the circuit to protect the buffer IC. If you accidentally shorted the
output to ground the current would be limited to about 50mA, probably just low enough that the IC doesn't fry up!

The downside is that if the output has to either source or sink any current the output voltage will suffer. With zero or near zero current from the output
the voltage of the pin will be 4.5V to 5V when high and 0.5V to 0V when low ie full TTL voltage swing. If the output is required to source/sink 10mA then the high voltage
will be reduced to 3.5V - 4.0V and the low voltage will increase to 1.5V - 1.0V. That is to say that the overcurrent protection resistor is now affecting the voltage swing of the output
so much that its borderline for TTL output.

Note that PoKeys determined that the output voltage swing is still acceptable if the input has to source/sink 8 mA.

Your stepper driver inputs require 10mA to switch so your PoKeys is borderline to drive the signals into the stepper driver. This is why I want you
to measure the current. Its going to be touch and go whether it will work without some modification. I think it will work but we absolutely NEED TO MEASURE
THE INPUT CURRENT TO THE DRIVER INPUTS.

If you cant do it yourself find someone who can.

If it turns out that the current is not enough don't panic we can fix that with a amplifier or MOSFET...easy. Still I think that the combination should work as is
if only you would knuckle down and make the required measurement.

Craig
 

3564

PoKeys / Re: Pokeys, mach4 no go?!

« on: October 10, 2018, 04:33:24 PM »

Hi,
the attached pic is from the PoKeys manual,
depending on the type of output (with or without the resistor) the output may not
have the grunt to reliably signal your driver.

Just to be sure I just put the MM in between the circuit connecting the dir pins on both pokeys and driver right? so that this acts as wire so to speak?

Yes.

Did, not sure if correct, MM set to measure mA, MM pins acting as a connection between Pulse/step of controller and driver, no readouts what so ever.

Do you have another low current circuit that you know works just to be sure that your meter is good and
you know how to use it. Most multimeter current circuits have a fuse internal to the meter and its very common for that fuse to
have popped. The only way you can tell is to run some current thruogh it with a known good circuit.

3565

PoKeys / Re: Pokeys, mach4 no go?!

« on: October 10, 2018, 02:08:17 PM »

Hi,
MEASURE THE CURRENT!!!! If you don't know what current is exciting the photodiodes you don't know whether they
are working.

Craig

3566

PoKeys / Re: Pokeys, mach4 no go?!

« on: October 10, 2018, 01:38:10 PM »

Hi,
if you measure the current in the DIR circuit you will establish whether the logic you have used to wire the pins is
correct. Have you measured the current?

Craig

3567

PoKeys / Re: Pokeys, mach4 no go?!

« on: October 10, 2018, 04:24:14 AM »

Hi,
no, you have to remove the normal connection and replace it with the multimeter circuit.

In current mode you might think of the multimeter as 'a bit of wire with a probe at each end'. It just so happens that the 'box of tricks'
the current passes through measures and displays the current.

Craig

3568

PoKeys / Re: Pokeys, mach4 no go?!

« on: October 10, 2018, 02:55:11 AM »

Hi,
no, that measures voltage, you want to know the current.....current s responsible for the photodiodes light output
in the drives optocoupler. With insufficient current the light output decreases markedly then the phototransistor
won't switch or saturate like it should.

If your multimeter has a DC current measurement range, that would work. Remember when your multimeter is in current measuring
mode your probes are almost shorted together....if you forget and try to measure the supply voltage to earth say then you'll pop something.

Craig

3569

General Mach Discussion / Re: Question before my next Mach3 question.

« on: October 10, 2018, 02:15:08 AM »

Hi,

My Question is about the 3 spindle outputs from the Blue Card, the inverter and Mach3

Well that is the question isn't it......without the manual or manufacturers documentation it could be anything.
Do you have any information on it at all?

Craig

3570

PoKeys / Re: Pokeys, mach4 no go?!

« on: October 10, 2018, 02:07:53 AM »

Hi,
from the sound of the stepper on your video I would have guessed that the signaling current to the stepper drive is
marginal/not enough. Can you put an ammeter in the DIR line and establish what the signaling current is?. From the specs
it should be at least 10mA.

Craig