A system and method for controlling data communications between a server and a client device, such as a mobile device. The self-sealing area is greater than that of a traditional filling port, and reduces the severity of the consequences of an inadvertent puncture by a hypodermic needle during the filling process. Each of the ground rail, positive supply rail, negative supply rail, and the circuit block are coupled to a respective contact pad of the plurality of contact pads. The user often feels that for a small dose it is not as important to leave the needle unit within the body for the full waiting period and so does not allow the waiting period properly to elapse.