Duet 2 wifi to control spindle

speaker2animals

Hi, trying to set up a duet 2 wifi running RR3.3 to control a spindle on an Ooznest CNC.

If I run these commands:
M950 R1 C"e0heat" L1000
M563 P1 S"Spindle" R1
M3 P1 S1000

When I measure e0heat I get about 24V (dc)

I don't seem to be able to use "M3 P1 Sxxxx" to change the measured voltage on e0heat - it is either 24V or 0v.

I'm sure I'm missing something - can anyone give me hint as to what?

TIA
Tony

jay_s_uk

@speaker2animals what spindle are you trying to control? Are you sure it doesn't need 0-10v? If it does you'll need a PWM to analogue converter board

speaker2animals

@jay_s_uk I already have the PWM to analog converter, I’m trying to confirm that when I issue M3 Sxxxx the output actually changes before I connect the converter.

My testing so far has been inconclusive in that changing the value of S does not appear to affect the measured output - it is fully on all the time.

Thoughts, comments?

gloomyandy

@speaker2animals How are you measuring the output from e0heat? The signal will be a PWM signal that will basically be pulsing between 0 and 24V (assuming you are measuring between +24V and e0heat the e0heat output is switched on the 0V side), this signal will be pulsing many times a second (the actual frequency can be set with the Q parameter to the M950 command), the amount of "on time" v "off time" of this signal will be changed based on the S parameter to M3, but you will probably not be able to observe this unless you are using something like an oscilloscope or logic analyser to observe the output (don't use a logic probe/analyser unless you know hat you are doing as they may not like the 24V signal). If you are measuring the output with a simple volt meter I suspect it will just seem to be either 0V or 24V.

speaker2animals

@gloomyandy You are quite correct. I am measuring the voltage using a digital voltmeter. (I do not have access to an Oscilloscope) I had a suspicion that this may not show the variation in voltage because of the PWM. But I did not know enough about the subject to be sure. I will install the PWM to analog converter and measure the output from that.
Thanks for your comments. I think they were helpful.