UCCNC M10 Laser not turning off on M10 Q0 Command

[cncdrive]

OK, I see. And how is the laser control output from the UCCNC is routed from the UC100 to the laser controller's TTL input?
It mean is it running through any Stepcraft electronics? Just trying to figure out if there is anything which would distort/delay the signal between the UC100 and your laser controller board.

[mayhem2408]

Currently the TTL input on the laser is running from Pin 17 on the UC100 via a parallel breakout board. It was originally running through Stepcrafts Switchbox, but I bypassed that to try eliminate the problem.

[mayhem2408]

I am going to try a different breakout board tomorrow. The one I have uses opto isolators. I am going to try a simple patch panel break out board.

[cncdrive]

Yes, that is what I thought about to try, to connect the laser pin directly to cross this out, because it can be that the optocoupler is too slow for the laser signal.

[Robertspark]

Is 10khz not a bit fast as a carrier wave for uc100 to be switching M10 q 0-255

I mean in order to subdivide a pwm signal into 0-255 steps it would need to be switched very fast by way of sub division?

[mayhem2408]

Is 10khz not a bit fast as a carrier wave for uc100 to be switching M10 q 0-255

I mean in order to subdivide a pwm signal into 0-255 steps it would need to be switched very fast by way of sub division?

I am only using a 1KHz wave on the UC100, giving me about approximately 100 steps. I don't want to go much lower than that because I engrave at a resolution of 0.1mm and a feed of 2000mm/min. That's 333 pixels per second.

I use a 10KHz wave on my GRBL-Mega controller and get 10 bit resolution or 1024 steps. My laser driver as a switching speed of less than 100ns. I am considering upgrading to a UC400 very soon so I can use 400KHz kernel and with a Carrier of about 1500KHz I should get the full 255 steps. But I need to make sure UCCNC can do what I want first. In theory it supports what I want, just getting it to work in the problem at the moment.

[mayhem2408]

I have made up a short DB25 externtion lead with a fly out lead of pin 17s PWM signal. The result is exactly the same. This eliminates the Opto Isolators on my breakout board and any Stepcraft electronics.

Pulse Width Test.png (293 Bytes) Viewed 8760 times

[mayhem2408]

For the purpose of thorough testing, this is the Stepcraft machine, using the Opti Isolator Breakboard board, the stepcraft Switchbox and the same laser and driver. But using the GRBL-Mega instead of the UC100. As you can see, no problem. This definitely eliminates the laser/driver and all stepcraft gear.

[Robertspark]

Mayhem2408, I am not an expert of M10 qxxx use with a laser.

My question was sort of directed at cncdrive to consider.

You've provided more information which is great.

However I suspect there is a difference between gbrl and uccnc regarding the use of pwm and M10 qxxx

It sounds like you are trying to fire your laser directly using M10 qxxx, and I'm not sure if that is the purpose of M10 qxxx.

It sounds like you may be better using maybe an axis output.

Maybe I am not understanding your circuit and what you are trying to do (which is fine, I am sure cncdrive can now use the information you have provided to answer your question)

You talk about using M10 qxxx giving you 100 steps in a uc100 at 10khz. (Again I am no expert and would wait for cncdrive to reply) but I suspect you may not be understanding M10 qxxx.

M10 qxxx is scaled from 0% to 100% as 255 steps (according to the uccnc manual)

I don't think you can scale it from 0-100 unless you are using a macro to rescale the value. Also this is used to vary the pwm signal output from the UC motion controllers

Again don't shoot the messenger, please wait for in drive to reply, but I suspect with using UC motion controllers you are missing a piece of hardware. The reason why I say this is the Arduino board can be programmed to do everything and anything.

If motion controllers do motion, but they can also be programmed to do other things within reason. You mentioned the uc400 running at 400khz giving you 1500khz signal. That I do not believe is possible using just the output of the uc400 motion controller. The maximum pulse output is 400khz, it cannot step more than that.

Pwm is something slightly different.

It can have 255 steps , at 400khz kernel setting, the fastest you can set the pwm carrier wave is 400,000 / 255 = ~ 1568 Hz (i.e 1.5 khz ).... Not 1500khz as your last post

I've got to go to work now, I'll come back to this later

[Robertspark]

Mayhem, do you have a link to your laser which shows a wiring schematic.

In one of your earlier posts you mention the laser being able to switch up to 100ns signal.... Which is 10mhz and well beyond the capabilities of UC motion controllers

10mhz is quite a frequency and not only the hardware in achieving this frequency is very precise, but the wiring between it needs to be very precise to prevent noise, echo, resonance, capacitance etc between signal wires. I think you are missing a bit of hardware that will take a own signal and convert it to a high / adjustable frequency pulse train