Losing my MI's (or losing my mind)

[John_R]

Hey All,

Here's a strange one, anyone have an answer for this?

I have a V570 project that I built a few months back, all seemed good until the middle of last week.

seems that every morning when the machine is powered up, we find that all saved settings for the machine (stored in MI's) are at zero, as though the PLC was Initialized.

luckily I have all these settings hard coded into a subroutine so it is just a matter of "loading default settings".

but, still annoying...

I'm about ready to put a new PLC in and see what happens, but thought I'd reach out to the masses and see if anyone has experienced this.

JohnR

[Ausman]

Hi John, have you lost the bit in your mind that has told you to look at the battery?  Hmmmm? 

SB8, but also try a new one if possible.

cheers,

Aus

[Cam]

Check the Battery.  SB 8  0=good  1=low.

[John_R]

Hey Aus,

No, actually the battery was my first thought, and I changed it last Friday , and SB8 = 0

any other mind numbing ideas?

JohnR

[DaveE]

I had the same issue, however mine was my fault...

Timers were saved and loaded up on start up and then stored and recalled on start again, if they changed

Needless to say instead of loaded the saved number, I saved zero, and all my timers went away!

 

[Ausman]

Ohh well.  We are assuming the battery is good and actually making electrical stimulation.  Could you possibly check that it is actually seating properly, with some delicate meter probing?  And does SB8 change if you take it out?

Clutching at straws now.

1). What is SB9 showing?

2).  You haven't inadvertently got SB24, or SB300 firing off during shutdown?  Actually do a search.

3).  Actually DO an initialise and reset.  I have had occasional very odd behaviour that an I & R completely cures....must be something to do with "left-over" data. 

4).  Is the plc on a nice supply or perhaps needing a filter?  Or near anything doing lots of RFI?

5).  Vectors over-writing the area?  (Even though it is a pain, I always label everything to do with any vector work, so that I don't inadvertently use something in use)

6)  HMI data entry fields aren't momentarily active somehow during startup, and writing zeros? 

7) Is there expansion in use?  Check/wiggle all connections.

Good luck,

Aus

[sasdiscos]

I had a v350 that did the same, turns out it was faulty, sent me a new one. Never actually found out the problem.

 

Steve

[Ely]

Not really a solution to the problem, but perhaps a workable patch - you can initialize the values for power-up in the MI. Instead of running the function of restoring defaults, it'll load them up automatically. Will not help if the data is overwritten, but if that is the case, you'll have additional information to troubleshoot with and know it's not power issue.