I need to read digital inputs from multible machines(+30) ( Cycle time, counter, and alert) (each machine with its own board)
What sort of digital input? This could be anything from a pin going HIGH or LOW to 2Mbits of serial data.
Are you trying to use one Arduino to read from 30+ machines, or will there be 30+ Arduinos trying to send data to some other machine (Arduino or PC)?
The data is needed to be sent to a server of some sort and be able to read the data in real time.
That will require that each Arduino wear an ethernet shield, and be connected to a router. A 30+ port router is not going to be real cheap.
What the server does with the data is up to the server. Typically, the server just stores the data. Some application on the server then accesses the data and does something useful with it.
Don't rush out and buy 30+ Arduinos and 30+ Ethernet shields. It is likely that one Arduino can handle data from more than one machine (depending, of course, on what that data consists of). Make sure that the project works for a machine or 2 or 3 before you scale to 30+.