l have an MC2 and want to replace ,what is the closest replacement

There is no direct drop-in replacement for the MC2.

For a machine manufacturer looking at redesign, the recommendation is to look at the IQAN-MC4x series of controllers: 

Master controllers - IQAN-MC41/MC42/MC43 | ParkerSE

Modifying the IQANdesign project file is relatively straight-forward for an application engineer. 

What takes more time is redesigning the wiring harness and testing. 

If this is about aftersales replacement on an existing machine, the lowest effort is to get a spare MC2 module from the machine manufacturer, who probably has some stock for this purpose.