slc 5/03 eprom

I have a slc 5/03 that crashed. I had the guys send me the equipment and found that the eprom had the program stored. I went to go online with the processor and it allowed me to restore the config off of the eprom into the processor since the fault had dumped the memory. My question is, in the case of a fault that dumps the memory, is there anyway to make it reload the program off of the eprom using the keyswitch? this seems like a lazy question but the processor didnt have the keyswitch with it and I will give it a shot with my spare keyswitch tomorrow(which I didnt have with me), just wanted to see if it was possible to do a reload via keyswitch instead of by software. thanks.

Yes the eprom can be set to reload in case of failure, but I am not sure if it is with power cycle or key switch.

The SLC bootloader's morning

Yaawwwn. Wow, I slept hard last night. I don't even remember leaving the party.

OK, inventory check. Is there an EEPROM in my pocket ? Oh, good. Let's see what's in the initialization sector of the EEPROM.

Hey, look, the initialization sector says "Load On Corrupt Memory". OK, I'll check the RAM, it should still be good.

Man, maybe it's 'cause I haven't had any coffee, but that user program length looks wrong. I'll run a checksum.

Well, that didn't take long, since the RAM's empty and everything. I'll run that checksum again later, after I transfer this binary off the EEPROM and into RAM.

Oh, hey, that hit the spot. Loaded off EEPROM, checked the program in RAM, we're ready to get this party going.

Last thing, poke a bit to tell the user program they've lost retentive values. I swear, I don't think I left them on the roof of the car last night, but, whatever, they're gone now.

RUN TIME !!!!

Umm... YEAH, what KEN said.

The only time it ever happened to me, I was instructed by someone over the phone to disconnect the battery AND discharge the retention capacitor on the CPU card by shorting its solder terminals. The combination of those things completely wiped the ram and when I powered the unit up it reloaded itself from the chip..... just like Ken said.

: )

ANOTHER alternative is to use a DTAM.

Stationmaster

That should replace the manual description . Much more fun. Kind of like 'dude, what happened to my car?'

good info here. nobody has mentioned if you can get everything going without using software though. any takers?

diat150 said:

good info here. nobody has mentioned if you can get everything going without using software though. any takers?

Click to expand...

Yes, Ken did...

Initially, you have to tell the PLC to load the EEPROM, either on-fault or everytime it powers up. If you'll look in the PLC configuration (S registers), you'll find one of the bits that's called "Load On Corrupt Memory" (or something similar) Enable the proper bits and the PLC will automatically load from EEPROM.

If you don't intentionally change those bits, though, the default is to do nothing with the EEPROM. At that point, IMO, you have wasted your money when you purchased that EEPROM... After all, it's just excess baggage if you don't properly configure the PLC to read from it.

Ken's description, though it may seem silly, is really a very, very good description of what happens in the PLC on startup.

Set one or more of the circled bits depending on what conditions you want to cause the load from eeprom.

Do that when offline, then download it the the CPU. Go online, and while still in program mode, do a store to eeprom so that those bits are also set in the EEPROM copy of the program.

Depending on your comms method, you may get an error saying that the store to eeprom failed, but that message may be erroneous and simply mean that you lost communication during the store procedure before RSLogix received a message saying that it had worked.

You can test it by clearing the memory and cycling power.

This is very handy with 5/01 and 5/02 processors which have no keyswitch.

Ken Roach said:

...Last thing, poke a bit to tell the user program they've lost retentive values. I swear, I don't think I left them on the roof of the car last night, but, whatever, they're gone now.

RUN TIME !!!!

Click to expand...

That bit Ken referenced in his colorful explanation is S:5/8. You can check its status (or monitor it in the program...) to see if a load from EEPROM actually has occurred.

Paul

thanks guys, yall really helped me out on this.