On 2017/04/06 6:45 AM, Tim R wrote:
When I worked for a paper mill we had a machine lose memory, lightning storm I think. The Allen Bradley PLC had an EEPROM backup so we uploaded the program from it.

Counterintuitively to the maintenance section, "upload" to A-B means upload FROM the PLC, not TO the PLC. So we loaded the empty program into the EPROM, erasing it.

Not a problem, we had another EEPROM safely locked in a cabinet in the office.

Of course we repeated the same mistake on our only backup.


Ouch. I have done similar mistakes. That is why I have both on site and
off site backups these days.

John :-#(#

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