8i20 power supply variation.

After many -many many hours of having problems with random following errors in finally have found something that links. 
so, when it's not sunny outside the voltage i read on the 8i20 card is 315v dc. When the sun is in full swing it reads 325v dc. This doesn't seem to relate to anything I know, but I have no errors when the sun isn't doing much,  and  plenty when it is, I'm thinking that there is probably some induced ripple from our solar system,  and the dodgy fanuc power supply im using probably has a bad cap. Any ideas ???

Ripple should not make too much difference, you might plot the bus voltage in halscope
to see if there's anything suspicious.

I'd look at a component heating issue first. Maybe just below "bad things" when it's not sunny outside, and pushed over the edge when it's sunny outside.
TBH honest the sun is huge, like really huge current thinking has it at 99.8% of the TOTAL mass of the solar system, all the planets and sundry matter make up 0.2% of the solar system (and our sun isn't all that big). And whether it's sunny or not outside it's still fusing ~600 million tonnes of Hydrogen per second into ~596 million tonnes of helium, thus fusing continues (element by element) until all that is left is iron, then we die, and being twisted by magnetic fields and the rest. So basically it's always on, doing what the sun does best fussing atoms into other atoms, generating heat and all manner of electromagnetic radiation.

I'm pretty sure if the ripple was being caused by the solar system you'd be noticing many many more items playing up.

But if you really want to check on the cosmic microwave background grab an old CRT tv, turn it on and turn to a channel that has no terrestrial signal, it'll give a reasonable idea of the radiation around. That's what a small part of the static is.

I'm thinking more it's a bad filter cap and a rough infeed from the 3phase fronius solar inverter. It does bump the voltage up.

Hahaha I look stupid, I thought "our solar system" you meant the solar system, some kind of weird google translation. Not a solar inverter as mentioned later.

You have my permission to make as much fun at my expense as you feel necessary. I honestly feel I deserve it.

Sorry if you thought I was making fun of you. Please accept my apologies.

I'm waiting for some parts to turn up, going to build a power supply- three phase rectifier and 4 large caps, the fanuc one I've been using is basically a bridge rectifier I'm not sure how good the caps are,  if I power it up it displays a fault code. It has been 2metres under floodwater (two washing machines in 'merican speak). So i don't really trust it. The issues I have are during hard acceleration from stopped, or high speed travel(rapid moves). Say I'm moving an axis 8in - 200mm, it will throw an error at around the 7in mark, this i can fix if I lower the travel speed a bit. I never lose encoder position but I geuss the mesa cards have that under control.  I would have preferred an Ethernet style card, but not much was available during covid etc. I don't believe the computer is the issue from tests I've done and the bios settings in place etc. It never shows any errors about realtime etc.