Independent ATM owners will charge for the use of their machines, but that will maintain an incentive to grow their network. Otherwise, it is likely that the independents as a source of competition would diminish over time, reducing consumer choice.
Access to the system will be governed by a code, which caps the price of connections, so that new competitors cannot be unduly hampered by the incumbent players over-charging to connect. The essence of the changes is simple. People have always been paying, one way or another, to use ATMs.