A method of operating an insulin treatment system that includes an insulin pump and a pump controlling device is disclosed. The method includes receiving, by the pump controlling device, a request to execute a function that is included on the pump controlling device. The function is governed by a rule having a parameter. The method also includes requesting, by the pump controlling device, a value for the parameter from the insulin pump, and receiving the value from the insulin pump. Also, the method includes executing, by the pump controlling device, the function using the received value for the parameter.