The answer is yes.
Once you have your account setup with a valid processor and a correctly keyed pinpad(of course this has to be one that is supported) setup the pinpad on the RMS opos and wallah.
I would avoid PCCharge at all cost. you need an additional addon with PCCharge for debit and it doesnt always work correctly.
If you are going to go with middleware for processing go with TPI. Also by going with TPI this expands your acceptable hardware you can use like a hypercom 4150 or 4250.
Any questions let me know