5/04 Fault

[Switchman]

Check AB's knowledgebase ID 23987

I've run into just about this very thing several times on 5/03 and 5/04 with and without the programs ending up frapped. Every time it has proved to be the power supply. Good luck.

 

[exiled]

Cpu reset

Alaric

Tark, I have a SLC5/04 that I keep on my desk for experimenting with. Everyonce once in a while it does the same thing - faults out and I cannot go online. I think the battery is getting weak - esp since it spends most of the time turned off, ubt it doesn't give a battery alarm yet. I disconnect the battery and short the Vbb pin to the Gnd pin to reset the PLC and wipe memory. I've been able to get back online with it everytime that way. I don't know if that is of any help to you or not

I think i have the same problem on a SLC5/03. Used for test only so doesnt get powered up for long.
Was doing a reset, came up with a fault (number i forget) now cant get online to reset (i can commnicate over DH485 & 232) I get the option of loading from an eprom.

Are the Vbb & Gnd terminals the same in both processors? if so where are they?

If so how do you do you wipe the memory.

cheers dudes.

 

[Mickey]

exiled,
See PDF

 

[Tark]

I should have posted an update to this some time ago. But better late than never.

It was the power supply.

 

[Jimmie_Ohio]

I should have posted an update to this some time ago. But better late than never.

It was the power supply.

This is a perfect lesson to both novices and experts. Strange, unexplainable problems, especially when nothing "changed" seem to point to power issues in general and many times, power supplies in particular.

Glad you got your problem solved, Tark. I was surprised it took you so long. Your replies to the questions from others seem so thorough, I didn't think you'd get stumped for so long on this issue.

 

[R_Stone]

4 - 20 signals can cause math overflows if they are messed up. Have you been able to get the fault ID at all? Make sure that the analog signal is limited so it cant go out of bounds.

Good suggestion. I usually drop all of the I/O wiring (disconnect the swing out wiring connectors) and then reconnect them one by one. Most of the time I have found problems with field devices shorted or grounded. I have had very few actual PLC failures.

Robert

 

[Tark]

Glad you got your problem solved, Tark. I was surprised it took you so long. Your replies to the questions from others seem so thorough, I didn't think you'd get stumped for so long on this issue.

It's been fixed for a long time, I just forgot to post an update.