slc memory retention

I was working on some SLC's over the weekend and powered down the controls on both as we worked on the system they controlled. When I powered back up both were in Default (lost program) Since part of the work being done required some programming change I re loaded them. One showed battery and the other did not, (502 &503) I changed batteries but the 502 still goes to default on a power down. I saved to EEPROM on each but did not verify the save,
I have heard that sometimes it looks like it didn't load when it actually did?
I was using the UIC Cable. Luckily the PLC is only powered down when the main disconnect is off and apparently they only turn control power of. I worry if they get a power outage I'll get the call if they loos the program. Under Processor Status, Memory Module they have Memory Module Load on Boot
S:5/8 bit set to 1 all others are 0 , Should I make a change or probably get another old processor. Thoughts

We had this happen on a 5/03.
the power supply (memory retention capacitor) and battery circuit to the memory has failed and needs to be repaired. for me, I would get a 5/03. we use teamsesco to repair the units. it's half the cost of a new plc 5/02. teamsesco is a vendor of mine.
james

I have some 502‘s that I could test if you think you might be interested in.

I replaced the Processor yesterday with a 503, I know it was good since it had an old program still on it when I installed it because it came up with a name in Linx. Wend I changed my program from 501 to 503 and downloaded it everything was fine but when I power down and back up it faults and shows up in Linx as Default.
I tried several times making sure it was not set to boot from Memory Module (none installed) an it would not even show in Linxs until I had removed and reinstalled Processor then powered up. I cant think of anything in the programming that would cause this . Can it be a power Supply or back-plane issue. These was all used pieces they had in the plant that I pieced together to make an interface module to read off a DCM and swap I/O with another processor.

Replace the rack power supply.


Sounds like an internal short is draining the battery and it can't keep the RAM powered up to hold the program and data.


EDIT: ControlLogix power supplies have done this to me also.

I will do that first since its the easiest test and let you know, thanks

I_Automation said:

Replace the rack power supply.

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I would say 90% of the issues with the SLC's are power supply issue, I even had I/O issues that came back as a PS issue, no doubt the go to when strange things start to happen

Yes changing the power supply solved the issue. Thanks

geniusintraining said:

I would say 90% of the issues with the SLC's are power supply issue, I even had I/O issues that came back as a PS issue, no doubt the go to when strange things start to happen

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And the other 12-1/2% always seem to be a bad SLC analog card.

On a side note I also installed a 1761-NET -ENI I believe I got from www.plccable.com
(geniusintraining) along with some cables for it, everything fine once configured just wondering
why the RS-232 mini din has the notch instead of the flat. I didn't think it would work and was rough getting it in the first couple times but I guess it wore down enough to go in easier after flopping programming cables to run cables a few times.
I hope that was my problem the old AB one would stop comms with the Panelview and not the weintek HMI and I would cycle Powers to the NET-ENI to restore it. I know they have limited connections and this problem only started occurring after the 2nd HMI (WEINTEK) was added. I even took off the connection to machine from my office but it still would do this 4-5 times a day.

roxusa said:

On a side note I also installed a 1761-NET -ENI I believe I got from www.plccable.com
(geniusintraining) along with some cables for it, everything fine once configured just wondering
why the RS-232 mini din has the notch instead of the flat. I didn't think it would work and was rough getting it in the first couple times but I guess it wore down enough to go in easier after flopping programming cables to run cables a few times.

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First of all, thank you very much for the purchase... Yes they are a tight fit, its easy to make a PM02 cable with the flat side but unless you are buying thousands of them its hard to justify making a mold and having the female mini din 8 with the a flat side, the notch female is a off the shelf part and if it works we need to keep our cost down so we can pass on the savings to our customers, we dont make a lot of profit on them as we are selling them for a couple hundred bucks when others are selling them for 3 times that amount.

I_Automation said:

And the other 12-1/2% always seem to be a bad SLC analog card.

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And the other 14.28% is due to a bad program not working correctly... the program must have broke, you know they do that after about 10 years, they just get worn out and dont scan like they use to

geniusintraining said:

And the other 14.28% is due to a bad program not working correctly... the program must have broke, you know they do that after about 10 years, they just get worn out and dont scan like they use to

Click to expand...

I thought that was like 98% of the problem, but in the "Programming" category.


I was told that if my program was good enough that it wouldn't allow itself to be changed later.


And for the "10 years" - make that 3 months.