Issue with micrlogix 1400

Hey guys,
I am facing a weird issue with a micrologix 1400 series PLC installed in my facility.The IP address of the controller is set to default abruptly & as a result its communication with HMIs collapses.The PLC which is otherwise healthy runs for few weeks before IP settings are wiped out & I have to reenter the address for it to work..

What could be the issue? Could this be a hardware fault?

It could be that DHCP or BOOT UP are still enabled see bellow thread:
http://www.plctalk.net/qanda/showthread.php?t=94483

tarik1978 said:

It could be that DHCP or BOOT UP are still enabled see bellow thread:
http://www.plctalk.net/qanda/showthread.php?t=94483

Click to expand...

I have set the IP using the keypad , so I guess BOOTP might not be the cause.Futhermore, BOOTP issues surface with power recycling , but this problem occurs abruptly.

can you post a screenshot of your Ethernet channel configuration please?