Interfaces are provided which integrate mistake-proofing concepts in a way easily understandable by the operator and easily configured by a manufacturing engineer. This system, method and computer program utilizes a keystroke database in which keystrokes are associated with active screens and either fields on those active screens or functions that may be executed. The loss-less decoder is coupled to the data identifier and receives and decodes data of the first data type from the data identifier. The at least one outdoor unit communicates with the indoor units via a plurality of pipes, and includes an outdoor heat exchanger where heat exchange occurs. One method of software execution includes embedding a disk image in a system read only memory of a computer system; exporting the disk image through a universal serial bus interface after an operating system of the computer system loads; and executing software in the disk image in the computer system. Each air-cored insulating transformer includes a primary winding and a secondary winding configured to generate a voltage by a change of interlinkage of a magnetic field.