First of all, thank you for your valuable inputs. Answering to them below:
What is the complete catalog number of your ML1400?
Do you have another PS to try?
I am using 1766-ML1400. Yes, I do have another PS to try with, and I did that as well. No difference.
It sounds like the power supply is undersized, either for the MicroLogix alone or for one of the circuits connected to it.
Isolate the power supply and the MicroLogix only, and see if the controller still goes through that cycle.
No, the power supply is a proper 24V DC supply. The same PLC was working on the 24V DC supply earlier, suddenly it starts behaving like this. The power supply is only for the PLC. There are no other connections in the circuit. I was programming the PLC and hence had taken it out of the panel.
What it supposedly means from the User Manual:
I did refer the UM. Did not find any pointers to the problem I have been facing and hence posted here. That was kind of you to post the reference to the User Manual.
The POWER LED never flashes as a diagnostic indicator.
If it's turning on and off, the controller supply power is also turning on and off, or the controller is rebooting.
If the controller is receiving continuous steady power and is still cycling on and off, it is defective and should be replaced.
No, the power supply is giving a constant 24V DC. I used a multi-meter and tested it and also connected another PLC in the circuit. The other PLC is working fine, but not this one.
I also figured a problem with the controller and would be contacting Rockwell for this now.
First things to try.
1) Put a meter on the 24vdc to see if it is also going on and off.
2) Unhook all other loads except for the PLC power supply and try again.
3) Try a larger supply
Based on the symptoms I would suspect the PS or some other device on the 24VDC than I would the ML.
1. Used a multi-meter, the supply is constant 24V DC.
2. The PLC in this case was the sole load for the PS.
3. Do you recommend trying a supply more than the recommended 24V DC for the PLC. For more clarification on the problem, please read the replies I have given above.
Thank You.