Hello Chaps,
Mach3
this has happened to me at least twice in the last few months
when I switch the system on i find that one or both steppers have changed direction.
I dont know - maybe someone can throw some light on the subject.
We have been experiencing a lot of mains power outages.
In order to alleviate the situation I have installed a 60KW 3 phase  generator set .
could this have something to do with it? maybe phases mixed up?
any discussion will be welcomed
regards fred

Please install power EMI filter for your machine controller box.

If single phase something like
https://www.ebay.com/itm/Single-Phase-AC-Power-Line-EMI-Filter-AC-115-250V-50-60Hz-20A-Suppressor-/123684313976

If three phase
google..

thanksfor the tip
what does this actually do?
regards

fred

this has happened to me at least twice in the last few months
when I switch the system on i find that one or both steppers have changed direction.

I can't think of anything that could cause this, except maybe a bad .xml file, or a pirated Mach3 license file?

A power loss can't change any Mach3 settings.
I can't see how an EMI filter would do anything.

Mch 3 currupts teh XML when the PC looses power and cannot fully create /Save the XML. You SHOULD have saved off a copy of a good XML so you can restore it on power up after a power loss. You can create a Batch file to auto transfer teh backup file to the mach3 folder.

(;-) TP

thanksfor the tip
what does this actually do?
regards

fred

Here is a good read:-
https://product.tdk.com/en/products/emc/emc/power-line/technote/pdf/generaltec_power-line_en.pdf

I suspected that motor direction change is a malfunction cause by CONDUCTED NOISE along the power cable(s). Hence I proposed Mains Input EMI filter.
Motor direction is just a signal change at at dir pins of the BOB and not necessarily will corrupt  the MACH3  XML file.

I had a electronically controlled Centralized gas heater that blew 3 times and ALWAYS in WINTER just because I did not have Filters and/or Surge protectors installed. After I put in a filter, I have had over 10 years FREE of problem.