Hello shrawan;

Could you clarify your question a little bit? Please indicate which type and model of controller you are using, the part number of the module you want to change (and the part number you want to replace it with) in your system and the programming software you are working with.

There could be many reason to change a module in a project, aging of the equipment comes to mind.

Sometimes the existing part number is no longer available and the manufacturer suggests a slightly different part number as a replacement. sometimes the sensor in the field had to be changed and the existing input module is no longer adequate and must also be swapped. Until we know more about your project it is very difficult to help you out more precisely...

Hope this helps,

Daniel Chartier