Retentive data lost Micrologix1000

Deer

Member
Join Date
Jun 2002
Posts
124
Hi All,

Just want to know, what the meaning from "Retentive data lost " on Micrologix1000?
Yesterday, my Micrologix 1000 get fault.I have checked with RSLogix500, and the error is caused by retentive data lost.
On error tab(Processor status) the retentive data lost was set(s:5/8 =1).Problem will solve only if the s:5/8 =0, and I have done it.
My question is what cause and when the retentive data lost will occur, so in the future ,this error doesn't happend again.
Thanks all.


Regards,

Deer
 
http://www.ab.com/manuals/cp/1761-um003a-en-p.pdf

The above manual in chapter 14 page 7 or page 225 of Adobe Acrobat states:
The data files (input, output, timer, counter,
integer, binary, control, and status) are corrupt.


• Cycle power on your unit.
• Download your program and
re-initialize any necessary data
• Start up your system.
• Contact your local Allen-Bradley
representative if the error persists.
 
Retentive data lost

Other than your system program file 0, the retentive data will be in Timers, Counters, Input and Output files. These are MINOR faults and can be cleared by cycling power. These faults do not affect program files 2-15.

Too many variables to give you an exact fix but I had one experience that seems similar. I had a program that was getting a negative number placed into a timer, timers will not accept a negative number but will give you a fault instead. The problem was hard to isolate.

Sorry my help is limited but so is my experience with micrologic.

Good luck
Roger
 
noise problem

Micrologix and slc's are succeptible to noise. I have seen previous
posts on this subject here. If I am not mistaken one of the posts
here claimed that only earlier versions were highly succeptible to noise. AB may have done some improvements in terms of noise immunity
in recent years but I would suggest that you need to pay attention to
noise suppression.

1. Provide MOV's across all inductive loads on PLC's outputs.

2. Provide suitable noise filter at the PLC power terminals.

3. If you are using rs-232 to communicate to an HMI, i suggest that
you use an optoisolated cable or the very least use one of those
ring suppressors.
 
From my experience,Jiri is on the right track.We had a similar error showing up when our Micrologix faulted and we nailed it down to lack of suppression on a relay controlled from one of the outputs.We then proceeded to put a heavy earth wire on the earth terminal and made sure that we earthed to the frame of the S/Steel enclosure as close to the plc as we could and then suppressed the coil of the relay and we have had no more drama with it at all.Like all true blokes,I used to believe that the instruction booklets were just in there for packing purposes!Hope it helps mate.
Cheers,
Mark.
 
Thanks all for your reply, anyway our problem was solved with reset bit s:5/8( retentive data lost), I am just worry if this problem comes again.
Jiri, markmc, yes I think noise can caused this problem so the structure data (binary, timer, etc) corrupted , I should check the noise suppresion in my plc system.


Regards,

Deer
 
check the your earth wiring in the panel.....
if earth wiring loose or not proper grounding so problem occur in the PLC and many times PLC goes to Fault mode.....
you did good.........it's a same solution.......
 
Hi All,

Just want to know, what the meaning from "Retentive data lost " on Micrologix1000?
Yesterday, my Micrologix 1000 get fault.I have checked with RSLogix500, and the error is caused by retentive data lost.
On error tab(Processor status) the retentive data lost was set(s:5/8 =1).Problem will solve only if the s:5/8 =0, and I have done it.
My question is what cause and when the retentive data lost will occur, so in the future ,this error doesn't happend again.
Thanks all.


Regards,

Deer

I got called out tonight- same issue... Googled it, led me here. It would not stay in run until I set the bit manually to 0. Weird or what. I love this forum. Was home before 1:00 AM. Thanks guys😃
 
Hey! I may have a solution you never tried!!
Yesterday I bought a used micrologix1000 because mine has that Fault LED flashing and my plc can't be replaced or fixed (that's what I thought). Now that guy from who I bought the other plc use to fix plcs which is his job in fact. Here's our discussion:

Him: You have to manually clear the fault with RSlogix.
Me: I know I did it! I went in the STATUS table and clicked on 'Clear Major Error'. It
cleard both error bits S:5/8 Retentive Data Loss and S:1/13 Major Error Halt and
the Fault LED stopped blinking. But as soon I put the plc back on 'RUN mode', fault
is coming back.
Him: No no no, I meant that you have to 'MANUALLY' force the bits to zero. meaning
clicking in the error bit box and manually replace the '1' by '0'.

I was very sceptical about that, but going back home I couldn't wait to try it and what do you know IT WORKED !!!! So strange!! but it worked..the fault status is almost permanently cleared!! I still have to test my micrologix stability, but I can download program and run it without fault.
 
Lol Byron, I'm just reading your message. So you know that 'manual clear" solution.

Isn't it strange?? I mean, almost frustrating when I think about all those who had to buy another one without knowing that. I'm pretty sure AB knows that solution. Do they propose it?
 
My Micrologix 1000 PLC was Faulted RetentiveData Lost today.
I ended up changing S:5/8 from a 1 to a 0 and it is working again.
This was a very old PLC that has been running for years and years, so I don't think that it was a hardware issue.
Probably a loose connection or something.
The thing that surprised me was that the Clear error didn't go in and reset the bit, I had to reset it myself.

SetTo0.PNG
 
Probably not. If there is an error, and clearing the bit resets it without faulting the PLC, you could have a dangerous situation on your hands. Randomly changed setpoints and calculations? No thanks.

Alternatively, if it doesn't stop the program from faulting, it won't help because the program can't get to run mode to automatically clear the bit.
 

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