Hi Fellas;

Never seen one like this before...

Guy calls me to take a backup of RS-Logix application in a mcrologix 1200, I arrive at site only to find the red fault light on. RS-Linx does not establish a communication either. To unravel the fault, I need to go on-line right? Question is how... Is there a way to get out of this situation, without erasing the PLC logic.. I'd like to know ASAP.

My eternal thanks to anybody who can steer me through this..

Have a good one though...with my best wishes.

Raj S. Iyer

You might try its default comm. using the Comm Toggle Push Buttom, see PDF

I have had this before and needed to cycle the power to the Micrologix before I could establish connection.

Either Leadcommander has the correct answer or your going to have to replace it. If cycling power does not make the fault light flash then your not getting online and the unit must be replaced

For my own curiosity if the light does flash will you post the error code? I'm going to guess 8h

Must be human nature for people to think about backing up the program only after a major fault occurs :)

Thanx a million fellas,

Gratified to you all for the quick response especially from all the regulars here. Tell you what.. I've yet to see the day that a PLC problem posted here goes unhelped.

That red light was indeed on all the time and not blinking. Based on your input I've recommended the replacement of the ML-1200 and offered to re-develop the logic. So cheers to increased business and thanks once again. A month ago I was in San Diego visiting my brother there. Chance any of you stay anywhere near? so we could meet up over beer next time??

Bye for now, best wishes


Raj S. Iyer