Modicon 984-A145 Run Mode

[Guest Chris B]

I am using a Modicon 984-a145 and Proworx NXT 2.1 . It appears that I have lost the entire program in the PLC yet I am able to put the CPU in Run mode. I am waiting a couple of days for the replacement program to load back on. Does the ability to put it in run mode mean I need to look at hardware failures? Or can this PLC be placed in run mode without logic? I believe the program was lost due to an electrician disconnecting the battery with no power to the PLC. Thank you in advance for any help!

[Crossbow]

If there is no program, the Compact PLC will go into RUN mode. It is not a hardware problems. Your idea that perhaps the battery was removed while powered down is what usually causes 95% of program loss in the Modicons. They have no EEPROM or Flash RAM in the old units unless you buy a card. You can't even put a memory card in the Momentum or Quantum families (funny the newer PLCs would have less function than the old Compact)... Edited December 8, 2004 by Crossbow

[mariosanchez]

To prevent this problem ever occur again, all you have to do is purchase a cheapy memory card and stick it in there. Then if you lose power or battery, the controller will load the program from the memory card. Buy it on ebay! cheap memory card...