try with mremoteng and set ssh version 2 under protocol
besides this are you using the correct port with putty? or you need maybe to forward it through your router
This could be it, each router must have a local ip; putty should try to access an specified S4, that means that it would be, depending on your settings something like:
192.168.1.xx <- 1 antminer s4
192.168.1.xx+1 <- another antminer s4 and so on,
You have to use different ports for each s4 (update their internal configuration) and then, on your router 192.168.1.1 <- you should forward connections from the outside to each s4 using the port established for it. If you need further help, please, let me know your router so I can point you where to go.