Rate Control Module, maybe Raven Control Module?  It does automatic section shut off and rate control.  That'd be all you'd need/want if this was a fresh setup. 

It seems you have some components of a Raven system already, but you haven't provided much detail there.  It gets a lot fuzzier if you're trying to upgrade a system.  Pictures of all the components and/or cable part numbers would let the experts here help you out a lot more.  There's lots of versions of 'Raven cables' you could have in the cab.