Unable to Set Spindle Speed via G-Code <resolved>

[Nigelo]

Frankly, I'm surprised anything worked but at least you are now making progress. Why? Imagine trying to make sense of a phone call when you can only hear 1 word out of 3 in every other sentence and I'm not talking of selective hearing

I think you could also usefully tidy up / replace the wiring especially the loose foil shield near the VFD which looks dangerous from the photo. FWIW, I only use multi-core shielded cable

[cnckeith]

I noticed those as well – I am using a very high quality shielded ethernet cable, but will try a different one just for giggles.

Would that cause this kind of issue?

lots of things.. list is here.
https://centroidcncforum.com/viewtopic.php?f=61&t=1451

[ShawnM]

.....Why? Imagine trying to make sense of a phone call when you can only hear 1 word out of 3 in every other sentence and I'm not talking of selective hearing

This is a GREAT analogy Nigel. Well stated.