Abstract: The present invention concerns a method, apparatus, and article of manufacture which provides an efficient way to change the function of a programmable logic unit included in a control device--where the control device manages the operational characteristics of a hardware unit--without having to disable system access to the hardware unit during the updating process. The hardware unit remains fully functional throughout execution of the updating method. To perform the update, the hardware unit must be connected to a host system by at least two communication channels. Each communication channel includes a control device including a programmable logic unit. The programmable logic unit is pre-programmed by a first data set which establishes its predetermined operational characteristics. Upgrading the programmable logic unit is accomplished by logically removing one of the communication channels leading from the host system to the hardware unit.