Micrologix reverting to old program on power loss.

pharma1

Guest

P

• Apr 2, 2012

• #1

I am able to change the program on our Micrologix 1200 PLC. It accepts the new program and runs it without a problem. We shut the power down on the weekends because no one is here. When the plc powers back up, it runs the old program as if I never changed it. Any ideas?
Thanks

 

Mickey

Lifetime Supporting Member

Join Date

May 2003

Location

Palmdale,Ca

Posts

10,659

• Apr 2, 2012

• #2

Does it have a memory module?

 

OkiePC

Lifetime Supporting Member

Join Date

Mar 2005

Location

ENE of Nowhere Oklahoma

Posts

11,791

• Apr 2, 2012

• #3

Memory Module installed and:
a) low battery
b) noise or power surge + possible grounding issues
Solution: download one more time, leave the unit in Program mode, go online, and then go to RSLogix500 menu: Comms, EEPROM, Store to EEPROM. If the module is not write protected, your new program will now be stored on it.

Paul

 

pharma1

Guest

OP

P

• Apr 2, 2012

• #4

Yes it does have a memory module. And the machine has been there a while. The battery could be bad. I will also try the way OkiePC mentioned.

Thanks,
Dale

 

rguimond

Lifetime Supporting Member

R

Join Date

Jul 2009

Location

Escuminac

Posts

666

• Apr 2, 2012

• #5

The memory module is your problem. PLC is configured to boot from EEPROM. Either save the correct version to the EEPROM or change the configuration so it doesn't boot from EEPROM

 

pharma1

Guest

OP

P

• Apr 2, 2012

• #6

Just wanted to thank everyone. The eeprom was the issue. The eeprom did not have a battery or a place to put one. I wound up doing the solution that OkiePC suggested and it worked perfect.

Dale