PLC 5 Failure

[BobLfoot 301]

Had a PLC 5/40 processor fail yesterday and it struck me as odd the way in which it failed. On Friday the unit was running normall and we shut down the process. On Saturday we shut down power to the plant. Power was off for Saturday and Sunday. On Monday when the power was turned on the PLC showed a solid red PROC light. I assume the battery was dead, but no BATT lightf, and changed the BATT. Tried to communicate with serial but autoconfig would not find it. Tried to communicate with DH+ but no COMM Led's. Used BootP to set Ip Address of ethernet sidecar. It would respond to PING, but RsLinx could not see it. Replaced the PLC 5/40 and was able to lsee in Linx and load program. Any thoughts anyone, why a healthy processor would die just from lack of power.

[bikerdude 0]

Bob, If you have one of those in chassis power supplies, maybe a poor connection at the backplane connector? Power surge at plant power-up maybe. Is there a power filter? Could be lots of things including bad luck. We had a 5/40E die last summer. $7,000 for a refurbished unit, OUCH!!!! BD

[jstolaruk 9]

Even on a "lights out" weekend many of my customers leave the PLCs running. Some of it because they haven't kept up on replacing batteries but mostly because they don't want a rash of startup problems Monday morning.

[BobLfoot 301]

Has not proven cost effective to plan alternate power for all 100 plus affected plc's. Took enough red tape to get an alternate feed into the data center and keep servers and phones alive during "lights out". The power supply is not in cahssis but the along side unit. Grounding is also to spec as far as I can tell. Chalk it up to age and bad luck. Edited 16 May 2006 by BobLfoot

[OkiePC 14]

My plant has about 200 PLC5/30, 40, and 80 processors and we have only had 3 failures in fifteen years. The first one ended up being a power supply (external). The processor was revived in the office, after a tech swapped in a good one. The P.S. died the next day. The 2nd one was filled with water and also was later revived in the office. That night there were 5 PLC5s running when the panels were flooded with water from a massive roofleak. The others were dried out with compressed air and contact cleaner and started back up. Only one lost it's program, comms config and went to a default state, so we swapped it. The third one got hit with 480 through an input card. We lost the input card, the backplane, the processor, and the power suuply on that one. I credit this incredible reliability to the PLC5 itself , and our use of constant voltage transformers for the PLC, and HMI supply. We use SOLA cvs, and even during plant shutdowns and power ups, when the incoming voltage goes as high as 520V, we get a steady 120vac out of the transformers. Paul http://www.solaheviduty.com/products/power...tioning/cvs.htm

[Been Around 0]

Boblfoot, Thats great performance for 100 plc's. The PLC-5 is a great processor. not just now, but for a long time. They are tanks. I have replace 62,535 slc's before plc5 for power issues(ha-ha) no, but alot more You do keep a spare? im sure. Maybe that processor went out OGK Keep up great posts!

[BobLfoot 301]

Yes we have a spare 5/11, spare 5/40 and spare 5/80 in stores at most all times. we also run only 7 of 8 lines leaving about 4 or 5 re-assignable plc 5's as well.

[Been Around 0]

Man that's great, you must be in like plc, programming, troubleshooting ....... HEAVEN!

[BobLfoot 301]

or HECK as the situation dictates. When many go down at once it cannbe a pain.

[Been Around 0]

Yes sir, Been there. but a 100 plc'sssssssssssssssssssssssss

[Been Around 0]

Ok, Can't say enough good about realibity of these. I have taken a 5 just as you describle and shorted volitle chips on board and revived. It was a trick learn years ago. Be careful, although plc is dead anyway. haven't work in all situtations but plc5 in my demostrator here just powererd up after I revived it over 5 years ago. I test alot of programming and electronics with it. You know I have it bad, plc at home. actually 3 plc5/25

[Mickey 71]

I also have 3 PLC's at home. SCADAPACK, Microligix 1500 and PLC5/11 I'm just as possessed as you are. Edited 19 May 2006 by Mickey

[Been Around 0]

Yes it's a passion. I truly enjoy controls. I've been around some kind of controls since 1983. Had a good teacher. My father and experience. Seen alot of changes in plc's over the years. Theres not much of a better time to be in controls. Not to many years ago there was no support. I remember many times just a manual and enthuasism. This is a good forum, lots of good reading, no lack of opposing views. Although it seems everyone has the bug and honestly tries to give good information. Good luck with programming. You need turn your computer occasionally OK, We got off the subject of Boblfoot, Sorry. I have never seen a 5/40 do this. did have a couple of 5/15s and a 5/25. Sent off and had repaired. Mickey, if your ever board (right) try this classic site http://blueballfixed.ytmnd.com/

[OkiePC 14]

Since we're off topic a little anyway, that reminded me of a trick with the Atari where you could get two missiles at a time on Space Invaders by flipping the power switch off and on quickly. Most of the time it would lock up as it's little memory mind was scrambled. The PLC5 is a tank...Yes, I've said that myself many times...I remeber another one...the Atari 400. I used to leave it running for months to keep from having to reload my tape programs. It never ever once locked up unless I POKEd it the wrong way. And that darn membrane keyboard took a beating. I did the power flip thing on it a bunch too. It still worked just fine when I sold it a few years ago for $20. Wish I had PLC at home. Don't get to program at work anymore. Looking for a programming job elsewhere even if it means a pay cut. Maybe I can find an Atari 800 on Ebay? PEACE