Control Logix L5555

[dleehanson 0]

Has any body experieced memory loss with these controller. It seems to happen at random, no real sympton has been established. I beleive it is running version 12.24 firmware, i am not positive on this rev. Thanks

[Contr_Conn 4]

First, you should upgrade to the latest FW revision 12.27. This probably will correct memory loss issue. If you still have problem then you can contact techsupport to get Fault Log extraction utility. Memory loss may not create fault log, but you can try. If most of cases processor intentionally marks program as invalid if firmware detects illegal operation or found program corrupted. It's safer to have no program than execute corrupted one.

[gravitar 3]

Have you first ruled out the standard causes.. Proper grounding, clean power, no un-suppressed inductive loads, hi-voltage and lo-voltage wiring in separate raceways?

[dleehanson 0]

This plc is powered through a UPS. Grounding and isolation is good.

[TechJunki 0]

I have had the same problems with the 5555's, memory loss at random... I think this is an inherit problem... Have learned to deal with it as no one seems to have a "real fix". I have noticed this mostly with ver. 12 Firmware. I don't think I have seen a problem with our current ver 13 or ver 15 processors. My best sugestion would be to upgrade to ver 13 or 15 to see if this fixes the problem..keep us posted if this solution works.

[Guest]

this can be a good thing ... or it can be a bad thing ... most people think that a UPS (ANY brand of UPS) will “clean up” a dirty power source ... the best ones will - to a certain extent ... but those can cost a LOT more money than some of the cheaper brands ... the cheaper ones can actually cause more problems than they correct ... basic idea: while the plant power is on, the UPS is charging its batteries ... the PLC receives its power from the plant’s AC line ... when the plant’s power fails (or even flickers), the UPS must quickly switch over and start converting/inverting its stored DC battery power into AC for the PLC ... in the brief transition from line power to inverter power, there can be a MAJOR spike in the output voltage ... this quick high-voltage spike can confuse the PLC - and cause many different types of problems ... program loss is just one scenario ... personally I never thought of this “UPS spike” effect until I saw a side-by-side demonstration of various brands of UPS models ... of course the demonstration was performed by a guy who was selling the “high-priced-spread” - but the traces on his high-speed oscilloscope convinced me that he was telling the truth ... moral of the story: just because you’ve got a UPS in the line, don’t assume that all is well with the power ... going further ... I worked with one systems integrator who swore that they had NEVER/EVER had a PLC problem with “power” issues ... they ALWAYS used an expensive UPS ... ! AND ! ... they ALWAYS installed an expensive surge suppressor too ... they swore by that two-pronged solution - and they absolutely refused to install a PLC if the customer didn’t want to pick up the extra expense ... it doesn’t take too many emergency service calls to wipe out the profit margin on most jobs ... anyway ... that’s my two cents worth ... please come back and let us know how this turns out ... we’re all here to learn from each other’s experience ... finally ... I'd certainly check out all of those other excellent suggestions first ... I'm just trying to give you one more tree to bark up - just in case nothing else seems to help ...

[dleehanson 0]

guru I have had similar experiences with ups manufacturers in the past. The plc is powered off of the batteries at all times on this system. There is no actual transfer that takes place. Thanks for the suggestions.

[Ken Roach 194]

Are you using a non-AB HMI software package ? I've had significant problems with a major HMI vendor's ControlLogix Ethernet driver writing to protected memory in the Logix controller and causing a checksum error on the user logic files, which cleared the controller's memory. V13 firmware eliminated the loophole that Ethernet driver was exploiting, so some customers experiencing this particular problem chalked it up to "a problem with V12 firmware". I'm not saying that has to be the case in your installation, I'm just saying there are other possibilities.